Title of Invention

PROCESS FOR PRODUCING PROPYLENE AND AROMATIC HYDROCARBON

Abstract It is an object of the present invention to provide an improved process whereby the yield structure of the components can be varied by a simple method, and the products can be produced stably and efficiently in a process for producing propylene and aromatic hydrocarbons from a hydrocarbon feedstock containing C4-12 olefins using a medium pore diameter zeolite-containing catalyst. A process for producing is disclosed which comprises a propylene production step wherein a specific zeolite catalyst is used to remove a C4+ hydrocarbon component from a reaction mixture, and part of the hydrocarbon component is recycled as necessary without modification, and an aromatic hydrocarbon production step wherein all or a part of the C4+ hydrocarbon component is used as the raw material.
Full Text DESCRIPTION
PROCESS FOR PRODUCING PROPYLENE AND AROMATIC HYDROCARBONS,
AND PRODUCING APARATUS THEREFOR
Technical Field
[0001] The present invention relates to a process for producing propylene and
aromatic hydrocarbons by catalytic conversion and catalytic cyclization from a
hydrocarbon feedstock, and to a producing apparatus therefor.
Background Art
[0002] Thermal cracking has been widely used for obtaining propylene and
aromatic hydrocarbons from hydrocarbon feedstock, but by its very nature thermal
decomposition requires severe reaction conditions, and a common by-product is
methane, which is difficult to use as petrochemical feedstock. Moreover, the product
yields of propylene and other olefins and benzene, toluene and other aromatic
hydrocarbons as percentages of the decomposition product are generally limited, and
the yield structure is not sufficiently flexible among other problems.
[00O3] Patent Document 1 discloses a method wherein silver is carried on
crystalline aluminosilicate zeolite in order to improve selectivity for lower olefins.
Although propylene yield is improved by this method, the yield of aromatic
hydrocarbons is poor. Also, in methods for catalytic conversion of hydrocarbons
using zeolite, coke accumulates on the catalyst and must be frequently removed by
combustion to regenerate the catalyst, but the problem is that in the case of the acid
zeolite described above, repeated regeneration operations cause permanent
degradation of catalyst activity. This occurs because coke combustion generates
steam that hydrolyzes the zeolite, causing aluminum to be released from the zeolite
crystals and eliminating protons that are active sites in the catalyst. This poses a

serious problem that must be solved if proton-type zeolites are to be used in these
kinds of reactions.
[0004] Patent Document 2 discloses a proton-free zeolite catalyst along with a
method for using this catalyst to convert hydrocarbon feedstock into ethylene,
propylene and monocyclic aromatic hydrocarbons. The catalyst used in this method
has the advantage of being resistant to regeneration degradation, but is still
vulnerable to the problem of coking deterioration. Moreover, because the
aforementioned paraffin conversion reaction is an endothermic reaction, a large
amount of heat must be supplied to the reaction vessel. As a result, this method
requires a complex and expensive reaction system.
[0005] An effective means of increasing the flexibility of the propylene / aromatic
hydrocarbon yield structure is to obtain these components by separate processes.
However, the reaction technologies that have been used for each in the past need to
be improved in order to obtain both components efficiently and stably.
[0006] For the propylene production step, methods of catalytic conversion from
hydrocarbon feedstock containing olefins using catalysts containing zeolite have
been adopted, and there are many reports of methods for producing propylene from
hydrocarbon feedstock containing olefins by catalytic conversion using catalysts
containing zeolite. However, efficient, long-term and stable production of propylene
from hydrocarbon feedstock containing olefins by catalytic conversion using a
catalyst containing zeolite is difficult for the following reasons.
[0007] Propylene is an intermediate in reactions for converting olefins into
aromatic hydrocarbons in the presence of a zeolite catalyst, and is converted into
aromatic hydrocarbons by the subsequent reaction. Consequently, when attempting
to produce propylene by catalytic conversion of hydrocarbon feedstock containing
olefins using a catalyst containing zeolite, the catalyst activity and reaction conditions

need to be strictly controlled in order to obtain the desired product with a high yield.
That is, if the catalyst is too active or the contact time is too long, the resulting
propylene will be converted to aromatic hydrocarbons by the subsequent reaction.
Conversely, if the catalyst is not active enough or the contact time is too short, the
propylene yield will be poor. Because olefins are highly reactive, however,
deposition of coke on the surface of the catalyst is likely to occur during catalytic
conversion of the hydrocarbon feedstock containing olefins using the catalyst
containing zeolite. In continuous conversion reactions, the catalyst deteriorates due
to coking (coking deterioration), and catalytic activity quickly declines. Regeneration
operations are required as described above in order to reactivate the catalyst, but
after repeated regeneration operations catalytic activity can no longer be adequately
restored.
[0008] As discussed above, coking is particularly likely in catalytic conversion
reactions of the hydrocarbon feedstock containing olefins using catalysts containing
zeolite, and regeneration degradation is also extremely likely because of the
consequent need for frequent regeneration operations.
[0009] Patent Document 3 discloses a method for converting C4-12 olefins into
ethylene and propylene using a proton-free ZSM-5 zeolite containing an IB group
metal and having an SiO2 / Al2O3 ratio of from 200 to 5000. When a zeolite-
containing catalyst is used to selectively convert C4-12 olefins to propylene, olefins
with about 4 to 8 carbon atoms are produced as reaction products in addition to
ethylene and propylene. This is because the raw material olefins are dimerized and
decomposed by the catalyst, resulting in an olefin composition similar to the
equilIbrium composition under the reaction conditions. Consequently, in order to
efficiently convert the raw material olefins into propylene, the C4+ olefins in the

reaction product need to be efficiently recycled back to the reaction container by a
simple method, and converted to propylene.
[0010] Patent Document 3 describes a method for removing the heavy fraction
with a boiling point at or above that of the C8 aromatic hydrocarbons from the
reaction product and recycling the C4-8 olefins back into the reaction vessel, but this
method requires multiple separators to obtain the raw material for recycling, thereby
complicating the equipment and operations, so there is a demand for simpler
methods, but so far it has not been possible to achieve both efficiency (equipment,
operating costs and yield) and stable production. Patent Document 3 also makes no
mention of the effect on coking deterioration of the diolefin concentration in the
hydrocarbon feedstock. The higher the diolefin compound concentration in the
hydrocarbon feedstock, the more activity deteriorates due to coke production.
Removal of diolefins from the feedstock is highly unpractical on an industrial scale
because it requires that the feedstock be purified by pretreatment such as separation
by distillation, partial hydrogenation or the like.
[0011 ] For the aromatic hydrocarbon producing step, however, many methods
are known for producing aromatic hydrocarbons using zeolite catalysts. As in the
propylene producing step, the biggest problems with methods of producing aromatic
hydrocarbons by catalytic cyclization using a zeolite catalyst are controlling coking
deterioration during the reaction and controlling regeneration (permanent)
degradation that occurs when the coke on the deteriorated catalyst is removed by
combustion to regenerate the catalyst.
[0012] Many proposals have been made in recent years for preventing both
kinds of deterioration. Specifically, Patent Document 4 reports that coke precipitation
during the reaction and permanent degradation due to dealumination during catalyst
regeneration can be simultaneously controlled by using a high-silica zeolite catalyst

of a specific particle size that exhibits a specific surface acid site / total acid site ratio
and amounts of pyridine adsorption before and after steam treatment, or in other
words specific changes in acid site behavior. In this method, however, the preferred
method of synthesizing the zeolite is one using a seed slurry, which has low
productivity, and moreover the stable production range of ZSM-5 zeolite is narrow,
limiting the SiO2/ AI2O3 ratio so that the primary particles are likely to be relatively
large. According to Patent Document 4, both coking deterioration and regeneration
degradation are controlled, but because the zeolite particle size is relatively large, it
does not appear that coking deterioration is adequately controlled. A zeolite with a
smaller primary particle size would be preferable, but according to Patent Document
4 this results in greater accumulation of coke during the reaction, and more rapid
regeneration (permanent) degradation. These are serious obstacles to the industrial
manufacture of aromatic hydrocarbons.
[0013] An example using a proton-free zeolite is given in Patent Document 2.
The catalyst used in this method is effective at resisting regeneration degradation as
described above, but the problem of coking deterioration remains. Consequently,
coking deterioration is likely when the hydrocarbon feedstock contains large amounts
of olefins. Moreover, this document makes no mentioned of the effect of the particle
size of the zeolite used in the catalytic cyclization reaction.
[Patent Document 1] Japanese Patent Application Laid-open No. H02-184638
[Patent Document 2] WO 1996/013331, pamphlet
[Patent Document 3] WO 2000/010948, pamphlet
[Patent Document 4] Japanese Patent Application Laid-open No. H10-052646
Disclosure of Invention
Problems to be Solved by the Invention

[0014] It is an object of the present invention to provide a process for producing
propylene and aromatic hydrocarbons from hydrocarbon feedstock containing C4-12
olefins, wherein the yield structure of the two components can be varied by a simple
method, along with a producing apparatus.
Means for Solving the Problems
[0015] As a result of exhaustive research aimed at solving the aforementioned
problems, the inventors in the present invention concluded that it was desirable to
produce the different components in separate processes using specific zeolite
catalysts in order to easily vary the production ratios of the two target components,
propylene and aromatic hydrocarbons, and perfected the present invention based on
this finding.
[0016] That is, the first aspect of the producing process according to the present
invention provides:
[1] a process for producing propylene and aromatic hydrocarbons, comprising:
(1) a propylene production step wherein a hydrocarbon feedstock
containing 50 % by mass or more of at least one of C4-12 olefin is brought into contact
in a propylene production reactor with a molded catalyst A containing a first zeolite
fulfilling conditions (i) through (iv) below to thereby perform a catalytic conversion
reaction on the at least one of C4-12 olefin, resulting in a reaction mixture containing
propylene, the reaction mixture is separated into fraction C containing mainly
hydrogen and C1-3 hydrocarbons and fraction D containing mainly at least one of C4+
hydrocarbon, and propylene is isolated from the fraction C:
(i) having a medium pore diameter zeolite with a pore diameter of from
5 to 6.5 A;
(ii) containing substantially no protons;

(iii) containing at least one metal selected from the group consisting of
metals in Group IB of the periodic table; and
(iv) having an SiO2/ AI2O3 molar ratio of at least 800 but no more than
2,000; and
(2) an aromatic hydrocarbon production step wherein a raw material
containing entirely or partly all or a part of the fraction D is brought into contact in an
aromatic hydrocarbon production reactor with a molded catalyst B containing a
second zeolite fulfilling conditions (v) through (vii) below in a gaseous phase at
650°C or less:
(v) having a medium pore diameter zeolite with a pore diameter of from 5
to 6.5 A;
(vi) with a primary particle diameter in a range of from 0.02 to 0.25 µm; and
(vii) containing at least one metal element selected from the group
consisting of metal elements in group IB of the periodic table,
[2] the process according to item [1], wherein the hydrocarbon feedstock containing
50 % by mass or more of at least one of C4-12 olefin which is used in the propylene
production step contains 2.5 % by mass or less of at least one of C3-12 diolefin
compound,
[3] the process according to item [1] or [2], wherein the first zeolite contains silver,
[4] the process according to any one of items [1] to [3], wherein the first zeolite is an
MFI zeolite,
[5] the process according to any one of items [1] to [4], wherein a value obtained by
dividing an amount of component [% by mass] of the C6-8 aromatic hydrocarbons
produced in the propylene production reactor by a hydrocarbon partial pressure
[MPa] is 13 or less,

[6] the process according to any one of items [1] to [5], wherein, in the propylene
production step, 10 % by mass to 95 % by mass of the fraction D is recycled back to
the propylene production reactor and used as part of the hydrocarbon feedstock,
[7] the process according to any one of items [1] to [6], wherein the fraction C is
separated into fraction C1 containing mainly hydrogen and hydrocarbons of 1-2
carbon atoms and fraction C2 containing mainly hydrocarbons of 3 carbon atoms, and
at least part of the fraction C1 is recycled back to the propylene production reactor
and used as part of the hydrocarbon feedstock,
[8] the process according to any one of items [1] to [7], wherein the propylene
production reactor is an adiabatic fixed-bed reactor,
[9] the process according to any one of items [1] to [8], wherein a reaction
temperature for the propylene production step is from 500°C to 580°C, a partial
pressure of the hydrocarbon feedstock is from 0.05 to 0.3 MPa, and a weight hourly
space velocity of the hydrocarbon feedstock based on a weight of the molded
catalyst A is from 2 hr-1 to 20 hr-1,
[10] the process according to any one of items [1] to [9], wherein the molded catalyst
B contains at least one selected from the group consisting of the metals belonging to
groups IB, IIB, IIIB and VIII in the periodic table and compounds of these,
[11] the process according to any one of items [1] to [10], wherein the second zeolite
contains silver,
[12] the process according to any one of items [1] to [11], wherein the second zeolite
is an MFI zeolite,
[13] the process according to any one of items [1] to [12], wherein the aromatic
hydrocarbon production reactor is an adiabatic fixed-bed reactor,
[14] the process according to any one of items [1] to [13], wherein the fraction C is
separated into fraction C1 containing mainly hydrogen and hydrocarbons of 1-2

carbon atoms and fraction C2 containing mainly hydrocarbons of 3 carbon atoms, and
at least part of the fraction C1 is used as part of the hydrocarbon feedstock in the
aromatic hydrocarbon production step.
[0017] A preferred mode of the first aspect of producing process according to the
present invention provides a process for producing propylene and aromatic
hydrocarbons from a hydrocarbon feedstock, comprising the steps of:
(1) producing propylene by catalytic conversion from the hydrocarbon
feedstock, wherein the hydrocarbon feedstock containing 50 % by weight or more of
at least one of C4-12 olefin is brought into contact in a propylene production reactor
with a molded catalyst A containing a first zeolite fulfilling conditions (i) through (iv)
below:
(i) the first zeolite is a medium pore diameter zeolite with a
pore diameter of from 5 to 6.5 A
(ii) the first zeolite contains substantially no protons
(iii) the first zeolite contains at least one metal selected from
the group consisting of the metals in group IB of the periodic table, and
(iv) the first zeolite has an SiO2/AI2O3 molar ratio of at least
600 but no more than 2,000,
thereby performing a catalytic conversion reaction on the at least one of C4-12 olefin,
resulting in a reaction mixture containing propylene, the reaction mixture is separated
into fraction C containing mainly hydrogen and C1-3 hydrocarbons and fraction D
containing mainly at least one of C4+ hydrocarbon, and propylene is isolated from the
fraction C, wherein the propylene production process fulfills the following conditions
(v) and (vi):

(v) a value obtained by dividing an amount of component [%
by mass] of C6-8 aromatic hydrocarbons produced in the propylene production reactor
by a hydrocarbon partial pressure [MPa] is 13 or less;
(vi) 10 to 95 % by mass of the fraction D is recycled back to
the propylene production reactor and used as the hydrocarbon feedstock; and
(2) producing aromatic hydrocarbons by catalytic cyclization from a
hydrocarbon feedstock, wherein a part of the fraction D, as all or part of the
hydrocarbon feedstock, is brought into contact in an aromatic hydrocarbon
production reactor with a molded catalyst B containing a second zeolite fulfilling
conditions (vii) through (ix) below in a gaseous phase at 650°C or less:
(vii) the second zeolite is a medium pore diameter zeolite with
a pore diameter of from 5 to 6.5 A;
(viii) the second zeolite has a primary particle diameter in the
range of from 0.02 to 0.25 µm; and
(ix) the second zeolite contains at least one metal selected
from the group consisting of the metal elements in group IB of the periodic table,
wherein the zeolite-containing molded catalyst B also contains at least one element
selected from the group consisting of the elements belonging to groups IB, IIB, IIIB
and VIII in the periodic table.
[0018] The second aspect of the producing process according to the present
invention provides:
[15] a process for producing propylene and aromatic hydrocarbons, comprising:
(1) a propylene production step wherein a hydrocarbon feedstock
containing 50 % by mass or more of at least one of C4-12 olefin is brought into contact
in a propylene production reactor with a molded catalyst A containing a first zeolite
fulfilling conditions (i) through (iv) below to thereby perform a catalytic conversion

reaction on the at least one of C4-12 olefin, resulting in a reaction mixture containing
propylene, the reaction mixture is separated into fraction E containing mainly
hydrogen and C1-2 hydrocarbons and fraction F containing mainly at least one of C3+
hydrocarbon, the fraction F is separated into fraction F1 containing mainly C3
hydrocarbons and fraction F2 containing mainly at least one of C4+ hydrocarbon, and
propylene is isolated from the fraction F1:
(i) having a medium pore diameter zeolite with a pore diameter of from
5 A to 6.5 A;
(ii) containing effectively no protons;
(iii) containing at least one metal selected from the group consisting of
the metals in Group IB of the periodic table; and
(iv) having an SiO2/ Al2O3 mole ratio of at least 800 but no more than
2,000; and
(2) an aromatic hydrocarbon production step wherein a raw material
containing entirely or partly all or a part of the fraction F2 is brought into contact in an
aromatic hydrocarbon production reactor with a molded catalyst B containing a
second zeolite fulfilling conditions (v) through (vii) below in a gaseous phase at
650°C or less:
(v) having a medium pore diameter zeolite with a pore diameter of from
5 A to 6.5 A;
(vi) with a primary particle diameter in the range of from 0.02 µm to
0.25 µm; and
(vii) containing at least one metal element selected from the group
consisting of metal elements in group IB of the periodic table,
[16] the process according to item [15], wherein the hydrocarbon feedstock
containing 50 % by mass or more of at least one of C4-12 olefin which is used in the

propylene production process contains 2.5 % by mass or less of at least one of C3-12
diolefin compound,
[17] the process according to item [15] or [16], wherein the first zeolite contains silver,
[18] the process according to any one of items [15] to [17], wherein the first zeolite is
an MFI zeolite,
[19] the process according to any one of items [15] to [18], wherein a value obtained
by dividing an amount of component [% by mass] of the C6-8 aromatic hydrocarbons
produced in the propylene production reactor by a hydrocarbon partial pressure
[MPa] is 13 or less,
[20] the process according to any one of items [15] to [19], wherein, in the propylene
production process, 10 % by mass to 95 % by mass of the fraction F2 is recycled
back to the propylene production reactor and used as part of the hydrocarbon
feedstock,
[21] the process according to any one of items [15] to [20], wherein at least part of
the fraction E is recycled back into the propylene production reactor and used as part
of the hydrocarbon feedstock,
[22] the process according to any one of items [15] to [21], wherein the propylene
production reactor is an adiabatic fixed-bed reactor,
[23] the process according to any one of items [15] to [22], wherein a reaction
temperature for the propylene production step is from 500°C to 580°C, a partial
pressure of the hydrocarbon feedstock is from 0.05 MPa to 0.3 MPa, and a weight
hourly space velocity of the hydrocarbon feedstock based on a weight of the molded
catalyst A is from 2 hr-1 to 20 hr-1,
[24] the process according to any one of items [15] to [23], wherein molded the
catalyst B contains at least one selected from the group consisting of metals
belonging to groups IB, IIB, 1MB and VIII in the periodic table and compounds of these,

[25] the process according to any one items [15] to [24], wherein the second zeolite
contains silver,
[26] the process according to any one of items [15] to [25], wherein the second
zeolite is an MFI zeolite,
[27] the process according to any one of items [15] to [26], wherein the aromatic
hydrocarbon production reactor is an adiabatic fixed-bed reactor,
[28] the process according to any one of items [15] to [27], wherein at least part of
the fraction E is used as part of the hydrocarbon feedstock in the aromatic
hydrocarbon production step.
[0019] A preferred mode of the second aspect of the producing process
according to the present invention provides a process for producing propylene and
an aromatic hydrocarbon from a hydrocarbon feedstock, comprising:
(1) producing propylene by catalytic conversion from the hydrocarbon
feedstock, wherein the hydrocarbon feedstock containing 50 % by mass or more of at
least one of C4-12 olefin is brought into contact in a propylene production reactor with
a molded catalyst A containing a first zeolite fulfilling conditions (i) through (iv) below:
(i) the first zeolite is a medium pore diameter zeolite with a
pore diameter of from 5 to 6.5 A;
(ii) the first zeolite contains substantially no protons;
(iii) the first zeolite contains at least one metal selected from
the group consisting of the metals in group IB of the periodic table; and
(iv) the first zeolite has an SiO2/ AI2O3 mole ratio of at least
600 but no more than 2,000,
to thereby perform a catalytic conversion reaction on at least one of C4-12 olefin,
resulting in a reaction mixture containing propylene, the reaction mixture is separated
into fraction E containing mainly hydrogen and C1-2 hydrocarbons and fraction F

containing mainly at least one of C3+ hydrocarbon, the fraction F is separated into
fraction F1 containing mainly C3 hydrocarbons and fraction F2 containing mainly at
least one of C4+ hydrocarbons, and propylene is isolated from the fraction F1, wherein
the propylene production step fulfills the following conditions (v) and (vi):
(v) a value obtained by dividing an amount of component [%
by mass] of C6-8 aromatic hydrocarbons produced in the propylene production reactor
by a hydrocarbon partial pressure [MPa] is 13 or less; and
(vi) 10 to 95 % by mass of the fraction F2 is recycled back to
the propylene production reactor and used as the hydrocarbon feedstock, and
(2) producing aromatic hydrocarbons by catalytic cyclization from the
hydrocarbon feedstock, wherein a part of the fraction F2, as all or part of the
hydrocarbon feedstock, is brought into contact in an aromatic hydrocarbon
production reactor with a molded catalyst B containing a second zeolite fulfilling
conditions (vii) through (ix) below in a gaseous phase at 650°C or less:
(vii) the second zeolite is a medium pore diameter zeolite with
a pore diameter of from 5 to 6.5 A;
(viii) the second zeolite has a primary particle diameter in the
range of from 0.02 to 0.25 µm;
(ix) the second zeolite contains at least one metal selected
from the group consisting of the metal elements in group IB of the periodic table,
wherein this zeolite-containing molded catalyst B also contains at least one selected
from the group consisting of the metals belonging to groups IB, MB, 1MB and VIII in
the periodic table.
[0020] An aspect of a producing apparatus according to the present invention
provides:

[29] a producing apparatus for producing propylene and aromatic hydrocarbons from
a hydrocarbon feedstock, comprising:
(a) a first reactor that receives the hydrocarbon feedstock and produces a
reaction mixture containing propylene;
(b) a separator that receives the reaction mixture and is connected to the
first reactor; and
(c) a second reactor connected to the separator, wherein the aromatic
hydrocarbons are produced,
[30] the producing apparatus according to item [29], wherein the separator has a
conduit for directly conducting a part of a separated product obtained from the
separator to the first reactor and second reactor,
[31] the producing apparatus according to item [29] or [30], wherein a part of a
fraction obtained in the separator is recycled and contained in the first reactor,
[32] the producing apparatus according to any one of items [29] to [31], wherein a
fraction that is obtained from the separator and contained in the first and second
reactors is a fraction containing mainly at least one of C4+ hydrocarbon,
[33] the producing apparatus according to any one of items [29] to [32], wherein a
part of a fraction containing mainly hydrogen and C1-2 hydrocarbons that is obtained
from the separator is contained in the first reactor and the second reactor,
[34] the producing apparatus according to any one of items [29] to [33], wherein the
separator is a distilling column or flash drum.
Advantageous Effects of the Invention
[0021] According to the producing process of the present invention, propylene
and aromatic hydrocarbons can be efficiently and stably produced from olefinic

hydrocarbon feedstock, and the production ratios thereof can be easily varied as
necessary.
[0022] Further, the amount of at least one of C3-12 diolefin compound contained
in the C4+ component produced in the propylene production reactor (which is the raw
material in the aromatic hydrocarbon production step) is reduced below the amount
of diolefin compounds in the hydrocarbon feedstock (which is the raw material in the
propylene production step and contains 50 % by mass or more of at least one of C4-12
olefin). Because they are highly reactive, diolefins are known to promote soiling of
the equipment and coking of the catalyst surface, so by reducing the amount of
diolefin compounds in the raw material for the aromatic hydrocarbon production step
it is possible to achieve more stable continuous operation in the aromatic
hydrocarbon production step.
[0023] Furthermore, according to the producing apparatus of the present invention, propylene and aromatic hydrocarbons can be efficiently and stably
produced from olefinic hydrocarbon feedstocks by using a simple apparatus and
especially a single separator.
Best Mode for Carrying Out the Invention
[0024] Embodiments of the present invention are explained with reference to the
drawings. The following embodiments are only examples for explaining the present
invention, and the intent is not to limit the present invention only to these
embodiments. The present invention can be implemented in a variety of modes as
long as these do not depart from the spirits of the present invention.
[0025] Figure 1 shows a schematic view of a producing apparatus according to
one embodiment for implementing the producing process according to the present
invention. Producing apparatus 1 according to the present invention comprises

propylene production reactor' 12, which receives the hydrocarbon feedstock and is
used to produce a reaction mixture containing propylene by catalytic conversion from
the hydrocarbon feedstock, one separator 16 connected to propylene production
reactor 12, which receives the aforementioned reaction mixture and is used to
separate the reaction mixture into specific fractions and then isolate the propylene,
and aromatic hydrocarbon production reactor 18, which receives a part of the specific
fractions described above, is connected to separator 16 and is used to produce
aromatic hydrocarbons by catalytic cyclization. Each reactor and separator is
connected via conduit 20 as shown in Figure 1. Specifically, separator 16 is
connected via a conduit which conducts the separated product obtained in separator
16 directly to propylene production reactor 12 and aromatic hydrocarbon production
reactor 18.
[0026] Propylene production reactor 12 receives the hydrocarbon feedstock via
heat exchanger 10, and a reaction mixture containing propylene is obtained by
catalytic conversion inside reactor 12 by means of contact with the zeolite molded
catalyst A described below. Note that this heat exchanger 10 can heat the
hydrocarbon feedstock being supplied to producing apparatus 1 according to the
present invention using the heating value of the hydrocarbon fluid inside propylene
production reactor 12. The reaction mixture containing propylene that is obtained in
propylene production reactor 12 is compressed as necessary by compressor 14 and
sent to separator 16.
[0027] A part of the specific fractions separated in separator 16, and specifically
a part of the fractions D or F2 described below, are preferably recycled back to
propylene production reactor 12, contained in this reactor 12 and subjected to
catalytic conversion. This recycling aspect is described below in the context of the
propylene production step.

[0028] In order for propylene to be efficiently produced in propylene production
reactor 12, a value obtained by dividing an amount of component (% by mass) of the
C6-8 aromatic hydrocarbons produced in the propylene production reactor by the
hydrocarbon partial pressure [MPa] is preferably 13 or less, more preferably 10 or
less.
[0029] In separator 16, propylene is separated from the reaction mixture
containing propylene that was obtained in propylene production reactor 12. Modes of
separation may include, but are not limited to, a mode by which the reaction mixture
is separated into fraction C containing mainly hydrogen and C1-3 hydrocarbons and
fraction D containing mainly at least one of C4+ hydrocarbon, and propylene is
isolated from fraction C, and a mode by which the reaction mixture is separated into
fraction E containing mainly hydrogen and C1-2 hydrocarbons and fraction F
containing mainly at least one of C3+ hydrocarbon, fraction F is separated into fraction
F1 containing mainly C3 hydrocarbons and fraction F2 containing mainly at least one
of C4+ hydrocarbon, and propylene is isolated from fraction F1. Specific examples of
separator 16 may include a distilling column, a flash drum (gas-liquid separator) and
the like, and a distilling column is preferred.
[0O30] Aromatic hydrocarbon production reactor 18 is a reactor for producing
aromatic hydrocarbons by catalytic cyclization, and aromatic hydrocarbons are
produced as described below by contact with zeolite-containing molded catalyst B
(described below) from all or a part of a specific fraction separated by this separator
16, specifically fraction D or fraction F2.
[0O31] Note that a fixed-bed reactor, moving-bed reactor, fluidized-bed reactor or
stream transport system can be used for propylene production reactor 12 and
aromatic hydrocarbon production reactor 18, and an adiabatic fixed-bed reactor is
preferred. Propylene production reactor 12 and aromatic hydrocarbon production

reactor 18 are preferably made primarily of a metal material such as carbon steel or
stainless steel.
[0O32] Producing apparatus 1 according to the present invention is suitable for
implementation of the producing process according to the present invention
discussed below, which comprises a propylene production step and an aromatic
hydrocarbon production step. Separation of the Cg+fraction has conventionally been
necessary when producing propylene and aromatic hydrocarbons from olefinic
hydrocarbon feedstock, but this is not required in producing apparatus 1 for
implementing the producing process according to the present invention. Therefore,
because producing apparatus 1 according to the present invention comprises
propylene production reactor 12 and aromatic hydrocarbon production reactor 18
with only one separator 16 between propylene production reactor 12 and aromatic
hydrocarbon production reactor 18, it is a simple apparatus capable of efficiently and
stably producing propylene and aromatic hydrocarbons from an olefinic hydrocarbon
feedstock.
[0O33] In the following explanation, the propylene production step and aromatic
hydrocarbon production step of the producing process according to the present
invention are discussed separately.
[0O34] [Propylene production step]
A hydrocarbon feedstock containing 50 % by weight or more of at least
one of C4-12 olefin is used in the propylene production step.
In the propylene production step, the term "hydrocarbon feedstock" refers
to a raw material containing mainly at least one selected from the group consisting of
the C1-12 hydrocarbons, such as for example the C1-12 normal paraffins, isoparaffins,
olefins, cycloparaffins (naphthenes) and cycloparaffins having side chain alkyl groups.
The term "olefin" used in the producing process according to the present invention

refers to cycloparaffins as well as straight-chain, branched and cyclic olefins. If the
olefin content is less than 50 % by weight, the propylene yield will be insufficient.
This hydrocarbon feedstock may also contain, as impurities, small quantities of tert-
butanol, methyl tert-butyl ether, methanol and other oxygen-containing compounds.
[0O35] The hydrocarbon feedstock can be used as is in the propylene production
step if the total content of propadiene, butadiene, pentadiene and other diolefin
(diene) compounds and methyl acetylene and other acetylene compounds is not
more than 2.5 % by mass. When more stable propylene production is desired, the
content should be 2 % by mass or less. These dieolefin compounds are highly
polymerizable and are known as a cause of coking deterioration. Of course, it is
generally desirable to reduce diene compounds as much as possible by a treatment
such as distillation, partial hydrogenation or the like, but such pre-treatment is of
course extremely impractical for industrial purposes.
[0O36] Desirable examples of hydrocarbon feedstocks that can be used in the
propylene production step include the following.
(1) C4 and C5 fractions isolated from products of thermal cracking of naphtha and
other petroleum hydrocarbons, and fractions obtained by partial hydrogenation of
diolefins into olefins in these C4 and C5 fractions;
(2) Fractions obtained by isolating and removing some or all of the butadiene and
isobutene from the aforementioned C4 fractions;
(3) Fractions obtained by isolating and removing some or all of the isoprene and
cyclopentadiene from the aforementioned C5 fractions;
(4) C4 fractions and gasoline fractions isolated from products obtained by fluidized
catalytic cracking (FCC) of vacuum gas oil and other petroleum hydrocarbons;
(5) C4 fractions and gasoline fractions isolated from cokers;

(6) C4 fractions and / or gasoline fractions isolated from hydrocarbons synthesized by
Fischer-Tropsch reaction (FT synthesis) from carbon monoxide and hydrogen.
These may be used individually, or two or more may be used as a mixture.
[0O37] In the propylene production step, the hydrocarbon feedstock such as
those described above is brought into contact in propylene production reactor 12 with
a specific zeolite-containing molded catalyst to thereby perform a catalytic conversion
reaction of at least one of C4-12 olefin contained in the hydrocarbon feedstock,
producing a reaction mixture containing propylene, and propylene is then separated
from the resulting reaction mixture in separator 18.
[0O38] In the propylene production step, a so-called "medium pore diameter
zeolite" with a pore diameter of from 5 to 6.5 A is used as the zeolite in the
aforementioned zeolite-containing molded catalyst A. The term "medium pore
diameter zeolite" refers to a zeolite with a range of pore diameters between the pore
diameters of small-pore zeolites (typically A-type zeolites) and the pore diameters of
large-pore zeolites (typically mordenite and X-type and Y-type zeolites), which zeolite
has an 10-membered oxygen ring in the crystal structure. Examples of the medium
pore diameter zeolites may include ZSM-5 and so-called pentasil zeolites, which are
structurally similar to ZSM-5. These may include ZSM-5, ZSM-8, ZSM-11, ZSM-12,
ZSM-18, ZSM-23, ZSM-35 and ZSM-39. Of these zeolites, the most desirable types
of zeolites are those represented as MFI structures according to the IUPAC
nomenclature for zeolite frameworks, and ZSM-5 is particular desirable. A zeolite
similar to ZSM-5 or ZSM-11 as described in PA. Jacobs and J. A. Martens, "Stud.
Surf. Sci. Catal.", 33, p. 167 to 215 (1987, Netherlands) can also be used.
[0O39] A zeolite containing substantially no protons can be used as the zeolite in
zeolite-containing molded catalyst A in the propylene production step. The term
"containing substantially no protons" in the producing process according to the

present invention means that the amount of proton (i.e., amount of acid) of the zeolite
is 0.02 mmol or less per gram of zeolite as measured by the liquid phase ion
exchange / filtrate titration method explained below. Preferably, the amount of proton
is 0.01 mmol or less per gram of zeolite.
[0040] The liquid phase ion exchange / filtrate titration method is described in
Intrazeolite Chemistry, "ACS Symp. Ser." 218, p. 369 to 382 (1983, USA); Nihon
Kagakukaishi (Bulletin of the Chemical Society of Japan), 3, p. 521 to 527 (1989,
Japan) and the like. Using this method, the amount of proton can be measured as
follows. A zeolite-containing molded catalyst is calcined in air and then subjected to
ion exchange treatment using an aqueous NaCI solution, after which the molded
catalyst is collected by filtration, and a filtrate is also obtained. The collected molded
catalyst is washed with pure water, and the whole amount of the resultant wash liquid
is collected and mixed with the aforementioned filtrate. The amount of proton of the
resulting mixed solution is measured by neutralization titration, and a value per
weight of the zeolite in the zeolite-containing molded catalyst is given as the amount
of proton of the zeolite. Ammonium ion-type zeolites and multivalent metal cation-
type zeolites (such as rare earth metal cation-type zeolites) are known to generate
protons by heating. Therefore, the zeolite-containing molded catalyst should be
calcined prior to measurement of the amount of proton by the aforementioned
method.
[0041] The zeolite of zeolite-containing molded catalyst A in the propylene
production step contains at least one metal selected from the group consisting of
metals belonging to Group IB of the period table (hereinafter referred to as "Group IB
metals"), or in other words from the group consisting of copper, silver and gold. Of
these metals, copper and silver are preferred, and silver is especially preferred. The
term "periodic table" in the present specification means the periodic table described

on pages 1 to 15 of the CRC handbook of Chemistry and Physics (75th Edition) by
David R. Lide et al. (published by CRC Press Inc., 1994-1995).
[0042] The term "Containing a Group IB metal" means containing the Group IB
metal in the form of the corresponding cations. However, in addition to cations of the
Group IB metal the zeolite may further contain the Group IB metal in another form,
such as oxide form. Examples of methods of incorporating the Group IB metal into
the zeolite may include methods of treating a zeolite containing no Group IB metal by
the conventional method, such as ion exchange, impregnation or kneading, and
preferably by an ion-exchange method. When the ion-exchange method is used to
incorporate the Group IB metal into the zeolite, a salt of the Group IB metal must be
used. Examples of the Group IB metal salts may include silver nitrate, silver acetate,
silver sulfate, copper chloride, copper sulfate, copper nitrate and gold chloride.
[0043] The amount of the Group IB metal contained as Group IB metal cations in
the zeolite-containing molded catalyst is not strictly limited, but is preferably from 0.01
to 5 % by mass, more preferably from 0.02 to 3 % by mass, based on the weight of
the zeolite. If the Group IB metal content is less than 0.01 % by mass, the catalytic
activity of the zeolite-containing catalyst will be unsatisfactory, while addition of more
than 5 % by mass will generally result in no further improvement in the performance
of the zeolite-containing catalyst. The Group IB metal content of the zeolite can be
determined by the known method such as x-ray fluorescence analysis.
[0044] Because in a preferred embodiment as discussed above the zeolite of
zeolite-containing molded catalyst A in the propylene production step contains
substantially no protons, the ion-exchange sites remaining after exchange with the
Group IB metal cations are preferably ion-exchanged with the cations of at least one
of the metal selected from the alkali metals and alkali earth metals. More preferably
they are ion-exchanged with the cations of at least one of the metal selected from the

alkali metals, and still more preferably with the cations of at least one of the metal
selected from the group consisting of sodium and potassium. In other words, the
zeolite of the zeolite-containing molded catalyst in the propylene production step is
preferably a zeolite that contains both the Group IB metal and at least one of the
metal selected from the alkali metals and alkali earth metals.
[0045] The method used to incorporate at least one metal selected from the
alkali metals and alkali earth metals into the zeolite may be one similar to the method
used for incorporating the Group IB metal into the zeolite. The content of the at least
one metal selected from the alkali metals and alkali earth metals differs depending on
the type of metal, but is preferably in the range of from 0.01 to 0.4 % by mass, based
on the weight of the zeolite in the case of sodium and 0.01 to 0.8 % by mass, based
on the weight of the zeolite in the case of potassium.
[0046] When preparing zeolite-containing molded catalyst A for use in the
propylene production step, there are no particular limits on the number of times or
order in which the method for incorporating at least one metal selected from the alkali
metals and alkali earth metals into the zeolite and the method for incorporating the
Group IB metal are performed. In any case, however, as discussed above, the
zeolite must be made to contain the metal in such a way that it also contains
substantially no protons. For example, when preparing a silver / sodium cation
exchange-type catalyst as the zeolite-containing molded catalyst for the propylene
production step, because some of the silver cannot be carried as silver cations if an
alkali component is present in the zeolite-containing molded catalyst, the zeolite is
preferably converted to a proton type during molding. Thus, the zeolite-containing
molded catalyst, which has been molded as a proton-type zeolite, is first exchanged
with sodium (preferably using an aqueous sodium nitrate solution) to convert it into a

sodium (proton-free) type, and then exchanged with silver cations (preferably using
an aqueous silver nitrate solution).
[0047] A SiO2 / AI2O3 molar ratio of the zeolite in zeolite-containing molded
catalyst A in the propylene production step is preferably at least 800 but no more
than 2,000. If the'SiO2/ AI2O3 molar ratio is less than 800, the zeolite-containing--
molded catalyst will deteriorate more rapidly due to coking in the conversion reaction,
resulting in a greater replacement frequency when the propylene production step is
accomplished by a fixed bed 2-reactor swing system for example, and therefore in
greater regeneration frequency. Consequently, regeneration degradation is also
accelerated. When the hydrocarbon feedstock contains diolefin compounds,
moreover, coking deterioration is more severe and the replacement frequency is
even greater, which soon makes it difficult to continue stable operation. To avoid this,
it is necessary to pre-treat the diolefin compounds in the raw material, which is
impractical for industrial purposes.
[0048] On the other hand, the SiO2/ AI2O3 molar ratio of more than 2,000, there
is a problem from the standpoint of catalyst preparation. To maintain the catalyst
activity of the zeolite-containing molded catalyst A with a high SiO2/Al2O3 molar ratio,
the ion-exchange rate of the zeolite must be increased so as to adjust the silver
content to an equivalent amount. However, the ion-exchange rate declines as the
exchange rate increases when preparing the proton-free, IB metal-exchanged
catalyst by ion exchange of a zeolite-containing molded catalyst.
[0049] To avoid this it is necessary to increase the metal concentration of the
exchange liquid. When the SiO2/ Al2O3 molar ratio of the zeolite exceeds 2,000, it
becomes more difficult to accomplish both ion exchange with the alkali metal and ion
exchange with the Group IB metal, and a long time and many steps are required for
catalyst preparation when the present invention is used industrially. An excess of

chemical liquid is also required, thereby greatly increasing the amount of wastewater
produced among other problems.
[0050] The SiO2 / Al2O3 molar ratio of the zeolite contained in the zeolite-
containing molded catalyst A used in the propylene production step is preferably at
least 900 but no more than 1,800, more preferably at least 1,000 but no more than
1,600. WO 2000/010948 discloses a similar zeolite catalyst. However, in this
example the focus is on a zeolite with a SiO2/ AI2O3 molar ratio of 300, and reaction
results are only disclosed up to 24 hours. A zeolite catalyst with a SiO2/ AI2O3 molar
ratio of 3,000 has also been described, but this was obtained by compression
molding of zeolite powder, and there are no examples of zeolite catalysts that are
industrially applicable.
[0051] The SiO2 / AI2O3 molar ratio of the zeolite can be measured by the
conventional method, such as for example the method in which the zeolite is
completely dissolved in an aqueous alkali solution or aqueous hydrofluoric acid
solution, and the resulting solution is analyzed by plasma emission spectrometry or
the like to determine the ratio.
[0052] A metalloaluminosilicate in which some of the aluminum atoms in the
zeolite framework are replaced by atoms of Ga, Fe, B, Cr or the like, or a
metallosilicate in which all the aluminum atoms in the zeolite frameworks are
replaced by such atoms, can also be used as the zeolite of zeolite-containing molded
catalyst A in the propylene production step. In this case, the SiO2/ AI2O3 molar ratio
is calculated after converting the contents of the aforementioned elements in the
metalloaluminosilicate or metallosilicate into moles of alumina.
[0053] If desired, at least one metal selected from the group consisting of the
metals in Groups lIb, III, Vb, Vlb, Vllb and VIII, such as V, Cr, Mo, W, Mn, Pt, Pd, Fe,
Ni, Zn, Ga or the like, may be included in zeolite-containing molded catalyst A in the

propylene production step in order to suppress coking deterioration and improve the
propylene yield.
[0054] If desired, the zeolite-containing molded catalyst A in the propylene
production step may be heat treated at 500°C or more in the presence of steam prior
to contact with the hydrocarbon feedstock in order to improve the resistance of the
zeolite to coking deterioration. This heat treatment is preferably performed at a
temperature of at least 500°C but no more than 900°C under a steam partial
pressure of 0.01 atm or more.
[0055] The zeolite-containing molded catalyst A in the propylene production step
may suffer from coking deterioration if used in the conversion reaction for a long
period of time. The deteriorated catalyst can be regenerated by burning off the coke
on the catalyst at a temperature of 400 to 700°C, usually in an atmosphere of air or a
gaseous mixture of oxygen and an inert gas (this treatment is hereinafter referred to
as "regeneration treatment").
[0056] For the zeolite-containing molded catalyst A in the propylene production
step, a porous, flame-resistant, inorganic oxide such as alumina, silica, silica /
alumina, zirconia, titania, diatomaceous earth or clay is generally mixed as a binder
or molding diluent (matrix) with the aforementioned zeolite to obtain a mixture which
is then molded, and the resulting molded body is used as the zeolite-containing
molded catalyst. When using the matrix or binder, the content thereof is preferably
from 10 to 90 % by mass, more preferably from 20 to 50 % by mass, based on the
total weight of the zeolite and the matrix or binder.
[0057] In the propylene production step, the reaction container is filled with the
zeolite-containing molded catalyst A such as that described above, and a catalytic
conversion reaction is performed with at least one C4-12 olefin. The catalytic
conversion reaction of the C4-12 olefin is preferably effected under the reaction

conditions described below, whereby the C4-12 olefins in the hydrocarbon feedstock
are converted to propylene with high selectivity, with substantially no reaction of
paraffins coexisting in the hydrocarbon feedstock. The reaction temperature is
preferably from 400 to 600°C, more preferably from 500 to 580°C. The pressure of
the hydrocarbon feedstock should be low, and is generally from 0.01 to 1 MPa,
preferably from 0.05 to 0.3 MPa. The weight hourly space velocity (WHSV) of the
hydrocarbon feedstock should be in the range of from 1 to 100 hr-1, preferably from 2
to 20 hr-1, based on the weight of the zeolite-containing molded catalyst. The contact
time between the hydrocarbon feedstock and the zeolite-containing molded catalyst
A is preferably 5 seconds or less, more preferably 1 second or less.
[0058] The hydrocarbon feedstock may be a mixture with a dilution gas.
Examples of the dilution gas may include an inactive gas such as hydrogen, methane,
steam, nitrogen or the like, but hydrogen dilution is not desirable. This is because
although hydrogen can be used to suppress coking deterioration of the catalyst, it
also causes hydrogenation reactions of the resulting propylene and the like, thereby
detracting from the propylene purity (propylene / (propylene + propane)). In the
producing process according to the present invention, hydrogen dilution is preferably
avoided because stable operation with minimal coking deterioration of the catalyst
can be achieved without diluting with hydrogen.
[0059] When the propylene production step is performed under the
aforementioned conditions under which there is substantially no reaction of paraffins,
the olefins in the hydrocarbon feedstock selectively undergo a conversion reaction
while paraffin conversion reactions are suppressed, and bi-products such as
methane, ethane, propane and the like that are produced by paraffin conversion are
controlled, facilitating separation and purification of propylene from the reaction
mixture.

[0060] In the propylene production step, a fixed-bed reactor, moving-bed reactor,
fluidized-bed reactor or stream transport system can be used as the propylene
production reactor wherein zeolite-containing molded catalyst A is brought into
contact with the hydrocarbon feedstock, and a structurally simple adiabatic fixed-bed
reactor is preferred.
[0061] Because the zeolite-containing molded catalyst A used in the propylene
production step resists deterioration due to coking, propylene can be stably produced
for a long period of time even using the fixed-bed reactor. The conversion reaction of
paraffins is highly endothermic, whereas the conversion reaction of olefins is slightly
endothermic or exothermic, depending on the reaction conditions. When olefins in
the hydrocarbon feedstock are selectively reacted under the aforementioned
conditions under which substantially no reaction of paraffins in the hydrocarbon
feedstock occurs, therefore, it is not necessary to supply reaction heat, and a simple
reactor system such as the fixed bed, single-stage adiabatic reactor can be used.
[0062] Propylene is separated from the propylene-containing reaction mixture
thus obtained. Specifically, in the first process of propylene separation the
aforementioned reaction mixture is separated into fraction C containing mainly
hydrogen and C1-3 hydrocarbons and fraction D containing mainly at least one of C4+
hydrocarbon, and propylene is separated from fraction C. In the second process, the
reaction mixture is separated into fraction E containing mainly hydrogen and C1-2
hydrocarbons and fraction F containing mainly at least one of C3+ hydrocarbon,
fraction F is separated into fraction F-i containing mainly C3 hydrocarbons and
fraction F2 containing mainly at least one of C4+ hydrocarbon, and propylene is
isolated from fraction F-i. These separation processes can be accomplished through
a combination of various known methods such as fractional distillation, extraction and
the like.

[0063] As discussed above, in addition to propylene the aforementioned reaction
mixture contains C4+ olefins and aromatic hydrocarbons. Consequently, a so-called
recycling reaction system, in which a part of the C4+ olefins in the reaction mixture are
recycled back to the reactor and reacted again, can be used to increase the
propylene yield based on the weight of the hydrocarbon feedstock containing 50 %
by mass or more of at least one of C4-12 olefin which is the feedstock in this propylene
production step, thereby making more effective use of the hydrocarbon feedstock.
[0064] In the producing process according to the present invention, a part of
fraction D or fraction F2 can be recycled back to the propylene production reactor and
used as part of the hydrocarbon feedstock. That is, the simplest possible recycling
process can be constructed by using the aforementioned fraction D or F2 as is as a
raw material for recycling without any refinement.
[0065] In order to efficiently obtain propylene from the recycling process in the
propylene production step, a value obtained by dividing the amount of component (%
by mass) of the C6-8 aromatic hydrocarbons produced in the reactor by the
hydrocarbon partial pressure [MPa] is preferably 13 or less, more preferably 10 or
less. This calculated value means that it is desirable, in order to efficiently obtain
propylene, to minimize production of the C decrease in catalytic activity is likely if the value is 13 or more or in other words if the
reaction conditions are such that aromatic hydrocarbons are easily produced. When
more of the C6-8 aromatic hydrocarbon component is produced in the reactor, not
only does the propylene yield decrease, but the ratio of C6-8 aromatic hydrocarbon
components and Cg+ aromatic hydrocarbon components in the recycled raw material
increases. As a result, accumulation and coking become a problem in the reactor.
The advantage of the calculated value of 13 or less is that the ratio of olefin
components increases in the Cg+ component, which converts relatively easily into an

aromatic hydrocarbon component, and the propylene yield can be increased by
recycling this component.
[0066] A propylene production ratio can be easily increased by increasing the
recycling ratio. Conversely, the aromatic hydrocarbon production ratio can be
increased by either decreasing the recycling ratio in the propylene production step or
stopping recycling and supplying more hydrocarbon components to the subsequent
aromatic hydrocarbon production step.
[0067] The method of suppressing production of C6-8 aromatic hydrocarbon
components in the propylene production step is not particularly limited, but a normal
method is to reduce the olefin conversion ratio of the hydrocarbon feedstock. The
olefin conversion ratio here is the olefin conversion ratio based on butene as
represented by the following formula.
Olefin conversion ratio (%) = {(C4+ olefin concentration in hydrocarbon
feedstock at reactor inlet - butene concentration in hydrocarbon components
at reactor outlet) / C4+ olefin concentration in hydrocarbon feedstock at
reactor inlet} x 100
A desirable olefin conversion ratio is 40 to 75 % by mass.
[0068] The method of reducing the olefin conversion ratio is not particularly
limited, but possible methods include raising the weight hourly space velocity of the
hydrocarbon feedstock, lowering the reaction temperature, or raising the SiO2/ AI2O3
molar ratio of the medium pore diameter zeolite in the medium pore diameter zeolite-
containing catalyst. Moreover, the zeolite of the present invention, which contains at
least one metal element selected from the group consisting of the metal elements in
group IB of the periodic table and substantially no protons, produces few C6-s
aromatic hydrocarbons in comparison with commonly used H-type zeolites, allowing

the olefin conversion ratio to be increased, which has the effect of increasing the
propylene yield.
[0069] In the propylene production step, the recycling ratio of fraction D or
fraction F2 is preferably from 10 to 95 % by mass, more preferably from 15 to 90 %
by mass. If the recycling ratio is less than 10 % by mass, the propylene yield will not
be greatly improved. If the recycling ratio exceeds 95 % by mass, paraffin
components contained in the hydrocarbon feedstock and C6-8 aromatic hydrocarbon
components produced in the reactor will accumulate in large quantities, increasing
the burden on the reaction apparatus.
[0070] The ratio of Cg+ hydrocarbon components in fraction D or F2 in the
propylene production process is preferably 20 % by mass or less, more preferably
15 % by mass or less. When the conditions are such that this ratio of Cg+
hydrocarbon components exceeds 20 % by mass, the ratio of aromatic hydrocarbon
components in this Cg+ hydrocarbon component will be greater, and propylene will
not be obtained efficiently.
[0071] The propylene production step is explained in more detail using an
example in which the hydrocarbon feedstock is a C4 fraction (fraction containing
mainly C4 hydrocarbons such as butane, isobutane, butene, isobutene and the like)
obtained from a steam cracking product of petroleum hydrocarbons.
[0072] Figure 2 shows a preferred embodiment of the recycling reaction system
of a propylene production step using a C4 fraction as the hydrocarbon feedstock. A
reaction mixture (comprising hydrogen and Ci+ hydrocarbons) is separated into a
fraction containing mainly hydrogen and C1-3 hydrocarbons (hereinafter referred to as
"H2~-C3 fraction") and a fraction containing mainly at least one C4+ hydrocarbon
(hereinafter referred to as "C4+fraction"). Examples of the apparatus used for
separation (C3 separator) may include a distillation column, flash drum (gas-liquid

separator) or the like, preferably a distillation column. Propylene is collected from the
resulting H2~C3 fraction. At least part of the C4+fraction can be recycled back to the
reactor and used as part of the propylene production raw material. When the
C4+fraction is recycled, the butane contained in the hydrocarbon feedstock is
concentrated in the C4+fraction. Since butane therefore accumulates when the entire
C4+fraction is recycled, butane accumulation can be controlled if the amount of the
C4+fraction that is recycled back to the propylene production reactor is limited to part
of the obtained C4+fraction.
[0073] The H2~C3 fraction may be further separated into a fraction containing
mainly hydrogen and C1-2 hydrocarbons (hereinafter referred to as "C2-fraction") and
a fraction containing mainly hydrocarbons with 3 carbon atoms (hereinafter referred
to as "C3 fraction"). Examples of the apparatus used for separation (C2 separator)
may include a distillation column, flash drum (gas-liquid separator) or the like,
preferably a distillation column. Ethylene can be collected from the C2-fraction, or
when selectively producing propylene, at least part of this C2-fraction can be recycled
back to the reactor, and the ethylene in the C2-fraction can be used as part of the raw
material. Because the C2-fraction contains hydrogen, methane and ethane in
addition to ethylene, hydrogen, methane and ethane accumulate when the entire C2-
fraction is recycled. Therefore, accumulation of hydrogen, methane and ethane can
be controlled if the amount of the C2-fraction that is recycled back to the reactor is
limited to only part of the obtained C2-fraction.
[0074] The aromatic hydrocarbon yield can also be increased by using this C2-
fraction as a raw material in the subsequent aromatic hydrocarbon production step.
Moreover, propylene collected from the C3 fraction can be used as is as chemical
grade propylene if the reaction conditions and separation conditions are set
appropriately.

[0075] The C4+fraction can also be separated into a fraction containing mainly C4
hydrocarbons (hereinafter referred to as "C4 fraction") and a fraction containing
mainly at least one of Cs+hydrocarbon (hereinafter referred to as "Cs+fraction"). The
C4 fraction can be separated from the C4+fraction either before or after the
C4+fraction is recycled. Examples of the apparatus used for separation (C4
separator) may include a distillation column, flash drum (gas-liquid separator) or the
like, preferably a distillation column. Part of the resulting C4 fraction and / or
Cs+fraction can be recycled back to the propylene production reactor and used as
part of the hydrocarbon feedstock.
[0076] Figure 3 shows another preferred embodiment of a recycling reaction
system using a C4 fraction as the hydrocarbon feedstock. A reaction mixture
(comprising hydrogen and Ci+ hydrocarbons) is separated into a fraction containing
mainly hydrogen and C1-2 hydrocarbons (hereinafter referred to as "C2-fraction") and
a fraction containing mainly at least one of C3+ hydrocarbon (hereinafter referred to
as "C3+fraction"). Examples of the apparatus used for separation (C2 separator) may
include a distillation column, flash drum (gas-liquid separator) or the like, preferably a
distillation column. Ethylene can also be collected from the C2-fraction. When
selectively producing propylene, at least part of this C2-fraction can be recycled back
to the propylene reactor as discussed above, and the ethylene in the C2-fraction can
be used as part of the raw material. It can also be used as the raw material in the
aromatic hydrocarbon production step in order to increase the aromatic hydrocarbon
yield.
[0077] Likewise, the C3+fraction can be further separated into a fraction
containing mainly C3 hydrocarbons (hereinafter referred to as "C3 fraction") and a
fraction containing mainly at least one of C4+ hydrocarbon (hereinafter referred to as
"C4+fraction"). Examples of the apparatus used for separation (C3 separator) may

include a distillation column, flash drum (gas-liquid separator) or the like, preferably a
distillation column. Moreover, propylene collected from the C3 fraction can be used
as is as chemical grade propylene if the reaction conditions and separation
conditions are set appropriately.
[0078] At least part of the C4+fraction can be recycled back to the reactor and
used as part of the propylene production raw material. When the C4+fraction is
recycled, the butane contained in the hydrocarbon feedstock is concentrated in the
C4+fraction. Since butane therefore accumulates when the entire C4+fraction is
recycled, butane accumulation can be controlled if the amount that is recycled back
to the reactor is restricted to only part of the obtained C4+fraction. As explained
above with reference to Figure 2, the C4+fraction can also be separated into a
fraction containing mainly C4 hydrocarbons (hereinafter referred to as "C4 fraction")
and a fraction containing mainly at least one of C5+ hydrocarbon (hereinafter referred
to as "C5+fraction"). The C4 fraction can be separated from the C4+fraction either
before or after the C4+fraction is recycled. Examples of the apparatus used for
separation (C4 separator) may include a distillation column, flash drum (gas-liquid
separator) or the like, preferably a distillation column. At least part of the resulting C4
fraction and / or Cs+fraction can be recycled back to the reactor and used as part of
the hydrocarbon feedstock.
[0079] [Aromatic hydrocarbon production step]
The zeolite used in zeolite-containing molded catalyst B in the aromatic
hydrocarbon production step has a pore diameter of from 5 to 6.5 A. That is, the
"medium pore diameter zeolite" is used. Examples of the medium pore diameter
zeolites are given above with reference to the propylene production step. Of these,
the most desirable types of zeolites are those represented as MFI structures

according to the IUPAC nomenclature for zeolite frameworks, and ZSM-5 is particular
desirable.
[0080] The zeolite of the zeolite-containing molded catalyst in the aromatic
hydrocarbon production step contains at least one metal selected from the group
consisting of metals belonging to Group IB of the period table (hereinafter referred to
as "Group IB metals"), or in other words from the group consisting of copper, silver
and gold. Of these metals, copper and silver are preferred, and silver is especially
preferred.
[0081] [ A "zeolite containing a Group IB metal" in the aromatic hydrocarbon
production step is preferably one that contains the Group IB metal in the form of the
corresponding cations. The IB metal cations carried by ion exchange on the zeolite
used in the aromatic hydrocarbon production step are a cause of cracking activity?/
[0082] Examples of methods for incorporating the Group IB metal into the zeolite
may include methods in which a zeolite containing no Group IB metal is treated by
the conventional method, such as ion exchange, impregnation or kneading, and
preferably is treated by an ion-exchange method. When the ion-exchange method is
used to incorporate the Group IB metal into the zeolite, a salt of the Group IB metal
must be used. Examples of Group IB metal salts may include silver nitrate, silver
acetate, silver sulfate, copper chloride, copper sulfate, copper nitrate and gold
chloride. Silver nitrate or copper nitrate is preferred, and silver nitrate is especially
preferred.
[0083] An amount of the Group IB metal contained in zeolite-containing molded
catalyst B is not strictly limited, but is preferably from 0.01 to 5 % by mass, more
preferably from 0.02 to 3 % by mass, based on the weight of the zeolite. If the Group
IB metal content is less than 0.01 % by mass, the catalytic activity of the zeolite-
containing catalyst will be unsatisfactory, while addition of more than 5 % by mass

will generally result in no further improvement in the performance of the zeolite-
containing catalyst. The amount of the Group IB metal contained in zeolite-
containing molded catalyst B can be determined by the known method such as x-ray
fluorescence analysis.
[0084] As well as being included in the zeolite as cations, the Group IB metal in
zeolite-containing molded catalyst B in the aromatic hydrocarbon production step
may also be included in a form other than cations as discussed below, such as an
oxide form. As discussed below the Group IB metal contributes strong
dehydrogenation ability to the catalyst of the present invention, and is included in
order to improve the aromatic hydrocarbon yield.
[0085] /The ion-exchange sites that are not exchanged with Group IB metal
cations of zeolite contained in zeolite-containing molded catalyst B in the aromatic
hydrocarbon production step are of course exchanged with protons or metal cations,
and are preferably exchanged with alkali metal cations or Group IIB, Group IIIB or
Group VIM metal cationsj
[0086] The SiO2 / AI2O3 molar ratio of the zeolite in zeolite-containing molded
catalyst B in the aromatic hydrocarbon production step is preferably at least 60 but
no more than 200. If the SiO2/ Al2O3 molar ratio is less than 60 the catalyst will be
somewhat less stable with respect to high-temperature steam and be less resistant to
regeneration degradation, which is undesirable because the activity is likely to
decline gradually in the course of repeated reaction and regeneration when the
present invention is applied industrially. If the SiO^/ AI2O3 molar ratio exceeds 200,
on the other hand, a sufficient amount of Group IB metal will not be carried by ion
exchange, detracting from cracking activity and from aromatic hydrocarbon yield.
Moreover, in order to maintain the catalytic activity of the zeolite-containing molded
catalyst with a high SiC>2 / AI2O3 molar ratio, the ion-exchange ratio of the zeolite

needs to be increased so as to adjust the Group IB metal content to an equivalent
amount, but the ion-exchange ratio of the Group IB metal then declines, increasing
the burden of catalyst preparation, which is highly undesirable for industrial purposes.
[0087] The SiC>2 / Al2O3 molar ratio of the zeolite in zeolite-containing molded
catalyst B in the aromatic hydrocarbon production step is more preferably at least 80
but no more than 120. The SiO2/ AI2O3 molar ratio of the zeolite can be determined
by the known method, such as for example a method in which the zeolite is
completely dissolved in an aqueous alkali solution or aqueous hydrofluoric acid
solution, and the resulting solution is analyzed by plasma emission spectrometry or
the like to determine the ratio.
[0088] A metalloaluminosilicate in which some of the aluminum atoms in the
zeolite framework are replaced by atoms of Ga, Fe, B, Cr or the like, or a
metallosilicate in which all the aluminum atoms in the zeolite frameworks are
replaced by such atoms, can also be used as the zeolite contained in zeolite-
containing molded catalyst B in the aromatic hydrocarbon production step. In this
case, the SiC>2 / AI2O3 molar ratio is calculated after converting the contents of the
aforementioned elements in the metalloaluminosilicate or metallosilicate into moles of
alumina.
[0089] The primary particle diameter of the zeolite contained in zeolite-containing
molded catalyst B in the aromatic hydrocarbon production step is in the range of from
0.02 to 0.25 µm. Preferably, the primary particle diameter is in the range of from 0.02
to 0.2 (j.m, more preferably from 0.O3 to 0.15 µm.
[0090] The primary particles of the zeolite contained in zeolite-containing molded
catalyst B in the aromatic hydrocarbon production step may be present as individual
particles or as secondary aggregates. In most cases the primary particles will
aggregate to form secondary particles, and since the primary particles assume

various forms, a method of measuring the Feret diameter (see The Society of
Chemical Engineers, Japan Ed., Kagaku Kogaku Binran (Chemical Engineering
Handbook), Revised 6th Edition, p. 233) from a scanning microscope image of zeolite
powder taken at 100,000x magnification can be adopted for measuring the primary
particle diameter in the present invention. Primary particles having this particle
diameter should preferably constitute at least 50 % by mass, more preferably at least
80 % by mass of the total.
[0091] The smaller the particle size of the zeolite, the greater the effective
surface area, which is known to be an advantage in terms of both activity and coking
deterioration. The particle size of the zeolite is affected not by the particle size of
secondary particles formed by aggregation of primary particles, but by the particle
size of the primary particles that can be distinguished at 100,000x magnification
under a scanning electron microscope. Consequently, in zeolite contained in the
zeolite-containing molded catalyst in the present invention the Feret diameter of the
primary particles as measured by the scanning electron microscopy of zeolite powder
at 100,000x magnification is preferably in the range of from 0.02 to 0.25 urn.
[0092] However, the crystal structure of this fine-particle zeolite is unstable, and
as described in Japanese Patent Application Laid-open No. H10-052646, the lattice
aluminum is easily detached by high-temperature treatment in the presence of steam,
and regeneration (permanent) degradation is likely due to this low hot water stability.
Surprisingly, however, with the zeolite-containing molded catalyst used in the present
invention hot water stability is much improved even in the case of a fine-particle
zeolite, and regeneration degradation can be greatly controlled, the amount of coke
accumulation can be inhibited. According to the present invention, a zeolite-
containing molded catalyst is achieved which is resistant to both the conventional
problems of coking deterioration and regeneration degradation.

[0093] IAt least one element selected from the group consisting of the elements
belonging to Groups IB, MB, 1MB and VIII in the period table is included in zeolite-
containing molded catalyst B in order to confer strong dehydrogenation ability on the
catalyst in the aromatic hydrocarbon production stepj The metals copper, zinc,
gallium, indium, nickel, palladium and platinum and oxides and complex oxides
thereof are preferred, and zinc and zinc compounds are most preferred.
[0094] Ion exchange or impregnation is generally used as the method of
incorporating metal elements and compounds of metal elements belonging to Groups
|B, MB, NIB and VIII in the period table into the zeolite-containing molded catalyst B,
in order to confer strong dehydrogenation ability on the catalyst in the aromatic
hydrocarbon production step. The amount of metal elements and compounds of
metal elements belonging to Groups IB, IIB, 1MB and VIII in the period table that is
incorporated into the zeolite-containing molded catalyst B is generally from 0.1 to 25
by mass %, preferably from 5 to 20 % by mass as elements, in order to confer strong
dehydrogenation ability on the zeolite-containing molded catalyst B in the aromatic
hydrocarbon production step.
[0095] In the zeolite-containing molded catalyst B in the aromatic hydrocarbon
production step, a porous, flame-resistant, inorganic oxide such as alumina, silica,
silica / alumina, zirconia, titania, diatomaceous earth or clay can generally be used as
a binder or molding diluent (matrix). Alumina or silica is preferred, and alumina is
especially preferred. A mixture obtained by mixing this with the zeolite described
above is molded, and the resulting molded body is used as the zeolite-containing
molded catalyst. When using the matrix or binder, the content thereof is preferably
from 5 to 50 % by mass, more preferably from 10 to 50 % by mass, based on the
total weight of the zeolite and the matrix or binder.

[0096] Zeolite-containing molded catalyst B in the aromatic hydrocarbon
production step can be subjected to heat treatment at 500°C or more in the presence
of steam prior to contact with the hydrocarbon feedstock with the aim of improving
resistance to coking deterioration. Heat treatment is preferably performed at a
temperature of at least 500°C but no more than 900°C, under a steam pressure of
0.01 atm or more.
[0097] When zeolite-containing molded catalyst B in the aromatic hydrocarbon
production step contains a mixture of Group IB metal-exchanged zeolite, zinc and a
compound thereof and alumina (which is a preferred example of the producing
process according to the present invention), high-temperature steam treatment
serves to stabilize the zinc component in the catalyst as zinc aluminate, thereby
achieving the additional object of greatly controlling scattering loss of zinc in the
reaction atmosphere. This effect is extremely advantageous for industrial application
of the present invention. The zinc aluminate in the present invention has an x-ray
diffraction pattern identical to the pattern given in JCPDS 5-0669NBS Circ, 539, Vol.
II, 38(1953).
[0098] In a preferred example of the producing process according to the present
invention, in the aromatic hydrocarbon production step an aromatic hydrocarbon
production reactor is filled with a specific zeolite-containing molded catalyst B such
as that described above, which is then brought into contact with the hydrocarbon
feedstock (described below) to perform the catalytic cyclization reaction and obtain
aromatic hydrocarbons. The aromatic hydrocarbons are separated and collected
from the resulting reaction mixture by known methods.
[0099] For the hydrocarbon feedstock in the aromatic hydrocarbon production
step, a fraction containing at least one of C4+ hydrocarbon produced in the propylene
production step described above is used as all or a part of the hydrocarbon feedstock.

Similarly, a C2-fraction produced in the propylene production step can be used as a
raw material, or light hydrocarbon components may be newly added as a raw
material.
[0100] The light hydrocarbon feedstock that is newly added in the aromatic
hydrocarbon production step is a light hydrocarbon feedstock containing at least one
selected from the olefins and paraffins, wherein the hydrocarbons have 2 or more
carbon atoms and a 90 % distillation temperature of 190°C or less. Examples of
such paraffins may include ethane, propane, butane, pentane, hexane, heptane,
octane and nonane. Examples of such olefins may include ethylene, propylene,
butene, pentene, hexene, heptene, octene and nonene. In addition, cyclopentene,
methylcyclopentane, cyclohexene and other cycloparaffins, cyclopentene,
methylcyclopentene, cyclohexane and other cycloolefins and / or cyclohexadiene,
butadiene, pentadiene, cyclopentadiene and other dienes may be included. A
mixture of such hydrocarbons may be used as the raw material, or methane,
hydrogen or an inert gas such as nitrogen, carbon dioxide, carbon monoxide or the
like may be included in the mixture as a diluent.
[0101] These diluents may constitute preferably 20% or less, more preferably
10% or less by volume. It is particularly desirable to use a mixture containing
saturated hydrocarbons and unsaturated hydrocarbons at a weight ratio of between 1
/ 0.33 and 1 / 2.33. The weight ratio of saturated hydrocarbons to unsaturated
hydrocarbons here means the weight ratio in the supplied mixture.
[0102] Desirable examples of light hydrocarbon components to be newly added
to a fraction containing mainly at least one of C4+ hydrocarbon produced in the
propylene production step may include the following as above:

(1) C4 and C5 fractions isolated from thermal decomposition products of naphtha and
other petroleum hydrocarbons, and fractions obtained by partial hydrogenation of
diolefins into olefins in these C4 and C5 fractions;
(2) Fractions obtained by isolating and removing some or all of the butadiene and
isobutene from the aforementioned C4 fraction;
(3) Fractions obtained by isolating and removing some or all of the isoprene and
cyclopentadiene from the aforementioned C5 fraction;

(4) C4 fractions and / or gasoline fractions isolated from products obtained by
fluidized catalytic cracking (FCC) of vacuum gas oil and other petroleum
hydrocarbons;
(5) C4 fractions and / or gasoline fractions isolated from cokers; and
(6) C4 fractions and / or gasoline fractions isolated from hydrocarbons synthesized by
Fischer-Tropsch reaction (FT synthesis) from carbon monoxide and hydrogen.
[01O3] In the aromatic hydrocarbon production step, the light hydrocarbon
feedstock may also contain, as impurities, tert-butyl alcohol, methyl tert-butyl ether,
methanol and other oxygen-containing compounds.
[0104] The reaction conditions for the aromatic hydrocarbon production step
differ according to the light hydrocarbon feedstock and particularly according to the
weight ratios of olefins and paraffins in the feedstock, but a temperature of from 300
to 650°C, a hydrocarbon partial pressure of between atmospheric pressure and 30
atmospheres, and a weight hourly space velocity (WHSV) of from 0.1 to 50 hr-1
based on the weight of the zeolite-containing molded catalyst are preferred. More
preferably the reaction temperature is in the range of from 400 to 600°C.
[0105] A fixed-bed reactor, moving-bed reactor, fluidized-bed reactor or stream
transport system can be used for the aromatic hydrocarbon production reactor in the

aromatic hydrocarbon production step, and a structurally simple adiabatic fixed-bed
reactor is preferred.
[0106] Zeolite-containing molded catalyst B in the aromatic hydrocarbon
production step may suffer from coking deterioration if used in the conversion
reaction for a long period of time. The deteriorated catalyst can be regenerated by
burning off the coke on the catalyst at a temperature of from 400 to 700°C, usually in
an atmosphere of air or a gaseous mixture of oxygen and an inert gas (this treatment
is hereinafter referred to as "regeneration treatment").
[0107] Because the zeolite-containing molded catalyst B in the aromatic
hydrocarbon production step is resistant to deterioration from coking, aromatic
hydrocarbons can be stably produced over a long period of time even using a fixed-
bed reactor. Since the zeolite-containing molded catalyst in the producing process
according to the present invention is less liable to dealumination in the presence of
high-temperature steam, it also resists permanent degradation (regeneration
degradation) during regeneration treatment, and consequently suffers very little loss
of activity even after repeated reaction and regeneration. Therefore, an aromatic
hydrocarbon compound can be produced stably and with high yield over a long
period of time. These features are extremely useful for industrial application of the
present invention.
[0108] Examples
The present invention is explained in more detail below by means of
examples and comparative examples, but the present invention is in no way limited
by these examples. Measurements in the examples and comparative examples are
performed as follows.
[0109] (1) Measurement of the amount of proton by liquid phase ion exchange /
filtrate titration

2.5 g of zeolite-containing molded catalyst that had been ground in a
mortar and baked in air at from 400 to 600°C was subjected to ion-exchange
treatment for 10 minutes with ice cooling in 25 ml of 3.4 mol / liter NaCI aqueous
solution. The resulting mixture was filtered, the molded catalyst was washed with 50
ml of pure water, and whole amount of the filtrate including the wash water was
recovered. This filtrate (including wash water) was analyzed by neutralizing titration
with 0.1 N NaOH aqueous solution, the amount of proton was determined from the
neutralization point, and the amount of proton based on zeolite weight was
determined based on the zeolite content of the zeolite-containing molded catalyst.
[0110] (2) Measurement of zeolite SiC>2 / AI2O3 molar ratio
0.2 g of zeolite was added to 50 g of 5 N NaOH aqueous solution. This
was transferred to a stainless steel microcylinder with a Teflon® inner tube, and the
microcylinder was sealed. This was then maintained for 15 to 70 hours in an oil bath
to completely dissolve the zeolite. The resulting zeolite solution was diluted with ion-
exchanged water, the silicon and aluminum concentrations in the diluted liquid were
measured with a plasma spectrometer (ICP unit), and the SiO/ AI2O3 molar ratio of
the zeolite was calculated from the results.
ICP unit and measurement conditions
Device : JOBIN YVON (JY138 ULTRACE), Rigaku Corp.
Measurement conditions:
Silicon measurement wavelength 251.60 nm
Aluminum measurement wavelength 396.152 nm
Plasma power 1.0 kw
Nebulizer gas 0.28 L/min
Sheath gas 0.3 to 0.8 L/min
Coolant gas 13 L/min

[0111] (3) Measurement of zeolite primary particle diameter
A zeolite powder sample was held with carbon adhesive tape on an
aluminum sample platform, and subjected to Pt deposition with an ion sputterer
(Hitachi E-1O30) to maintain conductivity.
SEM images were taken with a Hitachi FE-SEM (S-800), at an
acceleration voltage (HV) of 20 KV at magnifications of 500, 15,000 and 100,000.
Secondary particles are often formed by aggregation of fine primary
particles in the zeolite used in the present invention, so the Feret diameters of 20 or
more primary particles that were determined to be primary particles because they
appeared as single masses without cracks in the 100,000x scanning electron
microscope image were measured, and the average was given as the primary
particle diameter. When the primary particle diameter was so large that it could not
be evaluated in a 100,000x scanning electron microscope image, a scanning electron
microscope image of a different magnification was selected appropriately for
purposes of comparison, and the primary particle diameter was determined in the
same way.
[0112] (4) Gas chromatography analysis of reaction products
Device: Shimadzu GC-17A
Column: Supelco (U.S.) SPB-1 custom capillary column (inner diameter
0.25 mm, length 60 m, film thickness 3.0 (am)
Sample gas volume: 1 ml (sampling line maintained at 200 to 300°C,
liquefaction prevented)
Temperature program: Maintained for 12 minutes at 40°C, then raised to
200°C at 5°C / minute, then maintained for 22 minutes at 200°C
Split ratio: 200:1
Carrier gas (nitrogen) flow rate: 120 ml / minute

FID detector: Air supply pressure 50 kPa (about 500 ml / minute),
hydrogen supply pressure 60 kPa (about 50 ml / minute)
Measurement method: A thermal conductivity detector (TCD) and
hydrogen flame ionization detector (FID) were connected in a line, hydrogen and C1 and C2 hydrocarbons were detected with the TCD detector, and C3+ hydrocarbons
were detected with the FID detector. 10 Minutes after the start of analysis, detector
output was switched from TCD to FID.
[0113] (5) Reaction conversion ratio, reaction rate constant
The reaction rate constant K, which is an indicator of catalytic activity, was
determined by the following formula.
Reaction rate constant K = WHSV x ln[1/(1-X)]
[wherein X is the olefin conversion ration based on butene {(C4-8 olefin concentration
in raw materials - butene concentration in product) / C4.8 olefin concentration in raw
materials}].
[0114] [Example 1]
An Na-type ZSM-5 extrudate with a SiO2 / Al2O3 molar ratio of 1200
(containing 30 % by mass of SiC>2 binder, 1.6 mm Co., Ltd., Japan) was dispersed in an 0.02 N aqueous silver nitrate solution (10 cc/g-
molded zeolite), and subjected to ion-exchange treatment at 60°C for 1 hour, a
treatment that was repeated twice. This was then filtered, water-washed and dried to
prepare catalyst A-1. The Ag content of catalyst A-1 as measured by fluorescent x-
ray analysis was 0.22 % by mass.
A Hastelloy C reactor with an inner diameter of 27 mm was filled with
catalyst A-1, which was then steamed for 5 hours under conditions of temperature
650°C, steam flow rate 214 g / hr, nitrogen flow rate 400 NL / hr, and pressure 0.1
MPaG. After steaming treatment, the amount of proton of catalyst A-1 was 0.002

mmol / g as determined by liquid phase ion exchange / filtrate titration. 60 g of the
steamed catalyst A-1 was packed in a Hastelloy C reactor with an inner diameter of
27 mm.
The C4 raffinate-2 (hydrocarbons obtained by extracting and removing the
butadiene and isobutene from a C4 fraction obtained by steam cracking of naphtha)
shown in Table 1 was used as the raw material and supplied at a C4 raffinate-2
supply rate of 360.0 g / hr (WHSV = 6 hr-1) and a steam supply rate of 108 g / hr to
the reactor filled with catalyst A-1 in thereby perform a propylene production reaction
under conditions of reaction temperature 550°C, reaction pressure 0.1 MPaG, and
the resulting reaction product was supplied to a distillation column and separated into
a H2~C3 fraction and a C4+fraction. This propylene production reaction was
continued for 2 days.
The product yields (% by mass) are shown in Table 1. The value
obtained by dividing the amount of component (% by mass) of the C6-8 aromatic
hydrocarbons produced in the reactor by the hydrocarbon partial pressure [MPa] was
9.9.
The primary particle size of the zeolite was 0.06 \im as measured by
scanning electron microscopy with a magnification of 100,000x. 72 parts by mass of
H-type ZSM-5 (SiO2/ Al2O3 molar ratio = 92), zinc nitrate hexahydrate (10 parts by
mass as zinc metal) and alumina sol (18 parts by mass as AI2O3) were kneaded and
extrusion molded to 1.6 mm in diameter, 4 to 6 mm in length. After being dried at
120X for 4 hours, this was baked for 3 hours at 500°C to obtain a molded catalyst
containing zinc carried on zeolite. This catalyst was dispersed in a 1 N sodium
nitrate aqueous solution (10 cc/g-molded zeolite), and subjected to ion-exchange
treatment three times at room temperature for 1 hour each time. This was then
filtered, water washed and dried. This was dispersed in a 0.1 N silver nitrate

aqueous solution (10 cc/g-molded zeolite), and subjected to ion exchange for 2 hours
at room temperature. This was then filtered, water washed and dried to prepare
catalyst B-1.
The Ag content of catalyst B-1 as measured by fluorescence x-ray
analysis was 1.8% by mass.
A Hastelloy C reactor with an inner diameter of 27 mm was filled with
catalyst B-1, which was then steamed for 3 hours under conditions of temperature
650°C, steam flow rate 214 g / hr, nitrogen flow rate 400 NL / hr, and pressure 0.1
MPaG. After steaming treatment, 35 g of catalyst B-1 was packed in a Hastelloy C
reactor with an inner diameter of 27 mm.
Using this reactor, an aromatic hydrocarbon production reaction was
continued for 2 days with the C4+fraction obtained from the previous propylene
production reaction supplied at a rate of 98 g / hr with a reaction temperature of
515°C at a pressure of 0.5 MPa. The yield of C6-9 aromatic hydrocarbons was
47.4 % by mass 8 hours after the start of the reaction and 46.7 % by mass after 48
hours.
As calculated based on the C4 raffinate-2, the yield was 26.8 % by mass
for propylene and 30.6 % by mass for C6-9 aromatic hydrocarbons.
As shown in Table 1, the raw material in the aromatic hydrocarbon
production reaction (the C4+fraction obtained in the previous propylene production
reaction) contains fewer diene compounds than C4 raffinate-2. Diene compounds are
highly polymerizable and not only promote soiling of the equipment but are also
known to be a cause of coking deterioration, so more stable operation can be
achieved in the aromatic hydrocarbon production step if the propylene production
step is performed first.
[0115] [Example 2]

60 g of catalyst A-1 that had been steamed as in Example 1 was packed
in a Hastelloy C reactor with an inner diameter of 27 mm.
Using C4 raffinate-2 shown in Table 1 as the raw material, a propylene
production reaction was performed with a reaction temperature of 550°C, a C4
raffinate-2 supply rate of 220.3 g / hr, a recycled C4+fraction supply rate of 139.7 g /
hr (WHSV = 6 hr-1), a steam supply rate of 108 g / hr and a reaction pressure of 0.1
MPaG, the resulting reaction product was supplied to a distillation column and
separated into a H2~C3 fraction and a C4+fraction, and about 56% of the C4+fraction
was recycled back to the reactor.
The propylene production reaction was continued for 2 days, after which
the catalyst was regenerated under the following conditions: regeneration
temperature 500 to 550°C, regeneration pressure 0.5 MPaG, nitrogen + air flow rate
1008 NL / hr, oxygen concentration 1 to 5 vol %, regeneration time 10 hours. The
yields based on C4 raffinate-2 (% by mass) are shown in Table 1. The value
obtained by dividing the amount of component (% by mass) of the C6-8 aromatic
hydrocarbons produced in the reactor by the hydrocarbon partial pressure [MPa] was
8.9. During regeneration treatment the regeneration gas was sampled periodically at
the reactor outlet, the CO2 and CO concentrations were measured, and the amount
of coke was determined from these values. The coke yield was 72 ppm by mass as
determined by dividing the amount of coke by the total amount of raw materials fed
into the reaction.
An aromatic hydrocarbon production reaction was continued for 2 days
under the same conditions as in Example 1 except that the raw material was the
C4+fraction obtained in this Example 2. The yield of C6-9 aromatic hydrocarbons was
44.7 % by mass 8 hours after the start of the reaction, and 43.9 % by mass after 48
hours.

As converted to yields based on C4 raffinate-2, the propylene yield was
38.1 % by mass and the C6-9 aromatic hydrocarbons yield was 22.3 % by mass.
[0116] [Example 3]
A propylene production reaction was performed under the same
conditions as in Example 2 except that the C4 raffinate-2 supply rate was 279.1 g / hr,
the recycled C4++fraction supply rate was 80.9 g / hr (WHSV = 6 hr-1), and about
33% of the C4+fraction was recycled back to the reactor. The yields based on the C4
raffinate-2 (% by mass) are shown in Table 1. The propylene yield based on C4
raffinate-2 was 33.24 % by mass 2 hours after the start of the reaction, and 31-35 %
by mass 48 hours after the start of the reaction. The value obtained by dividing the
amount of component (% by mass) of the C6-8 aromatic hydrocarbons produced in
the reactor by the hydrocarbon partial pressure [MPa] was 4.8.
An aromatic hydrocarbon production reaction was performed under the
same conditions as in Example 1 except that the raw material was the C4+fraction
obtained in this Example 3. The yield of C&.9 aromatic hydrocarbons was 46.3 % by
mass 8 hours after the start of the reaction and 45.5 % by mass after 48 hours.
The yields based on C4 raffinate-2 were 32.4 % by mass for propylene
and 26.5 % by mass for C6-9 aromatic hydrocarbons.
The results of Examples 1 to 3 show that the production rates of the
desired propylene and C6-9 aromatic hydrocarbons can be varied by means of simple
changes in the operating conditions even using the same raw material.
[0117] [Comparative Example 1]
A molded catalyst containing H-type ZSM-5 with a SiO2/ Al2O3 molar ratio
of 407 (containing 30 % by mass of SiO2 binder, 1.6 mm dispersed in a 1 N aqueous sodium nitrate solution (10 cc/g-molded zeolite), and was
subjected to ion-exchange treatment for 1 hour at room temperature, a treatment that

was repeated three times. This was then filtered, water-washed and dried to prepare
a Na-type ZSM-5 / SiC>2 molded catalyst. This was dispersed in 0.00145 N aqueous
silver nitrate solution (10 cc/g-molded zeolite), and subjected to ion-exchange
treatment for 2 hours at room temperature. This was then filtered, water-washed and
dried to prepare catalyst A-2.
The Ag content of the catalyst A-2 as measured by fluorescence x-ray
analysis was 0.094 % by mass.
A Hastelloy C reactor with an inner diameter of 27 mm was filled with
catalyst A-2, which was then steamed for 5 hours under conditions of temperature
650°C, steam flow rate 218 g / hr, and nitrogen flow rate 220 NL / hr.
After steaming treatment, the amount of proton of catalyst A-2 was 0.0016
mmol / g-zeolite as determined by liquid phase ion exchange / filtrate titration.
A reaction evaluation test was performed as in Example 3 except that the
steamed catalyst A-2 was used. The propylene yield based on C4 raffinate-2 was
27.33 % by mass 2 hours after the start of the reaction and 22.61 % by mass 48
hours after the start of the reaction, giving a somewhat high propylene yield
differential of 4.7 % by mass.
An aromatic hydrocarbon production reaction was performed under the
same conditions as in Example 1 except that the C4+fraction obtained in this
Comparative Example 1 was used as the raw material. The yield of C6-9 aromatic
hydrocarbons was 47.9 % by mass 2 hours after the start of the reaction and 48.0 %
by mass after 48 hours.
As calculated from these results, the yields based on C4 raffinate-2 were
24.8 % by mass for propylene and 30.8 % by mass for C6-g aromatic hydrocarbons.
Comparing Example 3 with Comparative Example 1, not only did the
combined yield of propylene and C6-9 aromatic hydrocarbons drop from 58.9 % by

mass (Example 3) to 55.5 % by mass (Comparative Example 1), but there was
greater fluctuation in propylene yield.
The following are reference example involving only propylene production
reactions.
[0118] [Reference Example 1 ]
A H-type ZSM-5 extrudate with a SiO2 / Al2O3 molar ratio of 1000
(containing 30 % by mass of SiC>2 binder, 1.6 mm, purchased from Nikki Universal
Co., Ltd., Japan) was dispersed in a 1 N sodium nitrate aqueous solution (10 cc/g-
molded zeolite), and subjected to ion-exchange treatment at room temperature for 1
hour, a treatment that was repeated 3 times. This was then filtered, water-washed
and dried to prepare Na-type ZSM-5 / SiO2. This was dispersed in a 0.01 N silver
nitrate aqueous solution (10 cc/g-molded zeolite), and subjected to ion-exchange
treatment for 2 hours at room temperature. This was then filtered, water-washed and
dried to prepare catalyst A-3. The Ag content of catalyst A-3 as measured by
fluorescence x-ray analysis was 0.15 % by mass.
A quartz glass reactor with an inner diameter of 16 mm was filled with
catalyst A-2, which was then steamed for 5 hours under conditions of temperature
650°C, steam flow rate 27.6 g / hr, and nitrogen flow rate 140 Ncc / min. After
steaming treatment, the amount of proton of catalyst A-3 was 0.002 mmol / g-zeolite
as determined by liquid phase ion exchange / filtrate titration.
A Hastelloy C reactor with an inner diameter of 17 mm was filled with 10 g
of the steamed catalyst A-3.
Using this reactor and the C4 raffinate-2 shown in Table 2 as the raw
material, a propylene production reaction was performed with a C4 raffinate-2 supply
rate of 60 g / hr (weight hourly space velocity (WHSV) = 6 hr-1), a reaction
temperature of 580°C and a pressure of 0.1 MPaG, the resulting reaction product

was cooled to about 30°C with a heat exchanger at the reactor outlet and conveyed
to a gas-liquid separation drum, and the liquid (C4+fraction) was separated and
collected. The composition of the collected C4+fraction is shown in Table 2.
Next, a C4+ recycling test was performed for 24 hours under the following
test conditions using the collected C4+fraction and C4 raffinate-2 as the raw materials:
Reaction temperature 580°C, C4 raffinate-2 supply rate 30 g / hr,
C4+fraction supply rate 31-2 g I hr (WHSV = 6.1 hr1), reaction pressure 0.1 MPaG.
The analysis result for the reaction product 12 hours after the start of the
reaction was a propylene yield of 32.1 % by mass based on the C4-8 olefins in the
supplied raw material. However, the C6-8 component in the collected effraction was
considered to be all olefins apart from the aromatic hydrocarbons. The ratio of the
reaction rate constants K 4 hours and 24 hours after the start of the reaction [K(24
hrs) / K(4 hrs)] was 0.90.
[0119] [Reference Example 2]
A propylene production reaction was performed with C4 raffinate-2 under
the same conditions as in Reference Example 1 except that only 60 g / hr (WHSV = 6
hr-1) of C4 raffinate-2 was supplied as the raw material to the reactor. The analysis
result for the reaction product 12 hours after the start of the reaction was a propylene
yield of 31.1 % by mass based on the C4.8 olefins in the supplied raw material. The
ratio of the reaction rate constants K 4 hours and 24 hours after the start of the
reaction [K(24 hrs) / K(4 hrs)] was 0.87.
From comparing Reference Examples 1 and 2, it can be seen that there is
no ill effect on deterioration of the catalyst even if the C4+fraction is used as is as a
recycled material without removing the heavy component. The rise in propylene yield
from 31.1 % by mass (Reference Example 2) to 32.1 % by mass (Reference
Example 1) is due to propylene production from the Cg+ component.

[0120] [Example 4]
A H-type ZSM-5 extrudate with a SiO2 / Al2O3 molar ratio of 1220
(containing 30 % by mass of SiO2 binder, 1.6 mm) was dispersed in a 1 N sodium
nitrate aqueous solution (10 cc/g-molded zeolite), and subjected to ion-exchange
treatment at room temperature for 1 hour, a treatment that was repeated 3 times.
This was then filtered, water-washed and dried to prepare Na-type ZSM-5 / SiO2.
This was dispersed in a 0.0017 N silver nitrate aqueous solution (10 cc/g-molded
zeolite), and subjected to ion-exchange treatment for 2 hours at room temperature.
This was then filtered, water-washed and dried to prepare catalyst A-4. The Ag
content of catalyst A-4 as measured by fluorescence x-ray analysis was 0.095 % by
mass.
A Hastelloy C reactor with an inner diameter of 27 mm was filled with
catalyst A-4, which was then steamed for 5 hours under conditions of temperature
650°C, steam flow rate 214 g / hr, nitrogen flow rate 400 NL / hr, and pressure 0.1
MPaG. After steaming treatment, the amount of proton of catalyst A-4 was 0.002
mmol / g as determined by liquid phase ion exchange / filtrate titration. 60 g of the
steamed catalyst A-4 was packed in a Hastelloy C reactor with an inner diameter of
27 mm.
Using this reactor and the C4 raffinate-2 shown in Table 3 as the raw
material, a propylene production reaction was performed with a C4 raffinate-2 supply
rate of 268.7 g / hr, a recycled C4+fraction supply rate of 181-3 g / hr (WHSV = 7.5
hr-1), a reaction temperature of 550°C and a reaction pressure of 0.1 MPaG, the
resulting reaction product was supplied to a distillation column, the H2~C3 fraction
and effraction were separated, and about 58% of the C4+fraction was recycled back
to the reactor. The propylene yield [% by mass] based on the C4 raffinate-2 was

32.9 % by mass 2 hours after the start of the reaction and 30.4 % by mass after 48
hours.
An aromatic hydrocarbon production reaction was performed under the
same conditions as in Example 1 except that the C4+fraction obtained in this
Example 4 was used as the raw material. The yield of C&.9 aromatic hydrocarbons
was 45.5 % by mass 2 hours after the start of the reaction and 45.2 % by mass after
48 hours.
As calculated from these results, the yields based on C4 raffinate-2 were
31.7 % by mass for propylene and 24.8 % by mass for aromatic hydrocarbons.
This shows that two days of continuous operation can be accomplished
without any ill effect on deterioration even using a raw material wherein the diolefin
compound concentration is 2.25 % by mass.
[0121] [Example 5]
A reaction was performed under the same conditions as the aromatic
hydrocarbon production reaction of Example 2 except that a mixture of the
C4+fraction (60 g / hr) obtained in Example 3 and the C5 fraction shown in Table 3
(38 g / hr) was supplied as the raw material. The C6-9 aromatic hydrocarbon yield
was 44.1 % by mass 8 hours after the start of the reaction and 43.2 % by mass after
48 hours.
The ratio of the aromatic hydrocarbon component can be increased by
adding a fresh light hydrocarbon component as in Example 5. Specifically, when 60
g / hr of the C4+fraction obtained in Example 3 was used as the raw material the C6-9
aromatic hydrocarbon yield 8 hours after the start of the reaction was 46.3 % by
mass, or 60 g / hr x 0.463 = 27.8 g / hr. By contrast, when the mixture of Example 5
was used as the raw material, the C6-g aromatic hydrocarbon yield 8 hours after the
start of the reaction was 44.1 % by mass, or (60 + 38)g / hr x 0.441 = 41.0 g / hr.

This shows that the proportion of the aromatic hydrocarbon component can be
increased by adding a fresh light hydrocarbon component.
[0122] [Comparative Example 2]
A H-type ZSM-5 zeolite was synthesized by the method described in
Example 1 of the description of Japanese Patent Application Laid-open No. H10-
052646. The SiO2 / AI2O3 molar ratio of the resulting zeolite was 42. A zeolite
powder of this zeolite was photographed at 15,000x magnification under a scanning
electron microscope, and the primary particle size of the zeolite was measured and
found to be 1.54 \im.
A molded catalyst containing zinc carried on zeolite, catalyst B-2, was
obtained by the same methods as in Example 1.
A reaction was performed in the same way as the catalytic cyclization
reaction of Example 3 except that catalyst B-2 was used. The yield of C6-9 aromatic
hydrocarbons was 45.1 % by mass 4 hours after the start of the reaction and 42.7 %
by mass after 45 hours.
[0123] From comparing Example 3 and Comparative Example 2, it is
demonstrated that with the conventional H-type zeolite, hot water stability is much
less than with the catalyst of the present invention even if the zeolite used is one
having the physical properties stipulated in the invention disclosed in Japanese
Patent Application Laid-open No. H10-052646. This is because even if the zeolite
has a lower SiO/ AI2O3 molar ratio (has more reactivity sites), the yield of aromatic
hydrocarbons is low at the start of the reaction with an H-type zeolite. This means
that more permanent degradation (regeneration degradation) over time is likely in
industrial use. In terms of particle size, moreover, the primary particle size of the
zeolite is greater than that of the zeolite used in the zeolite-containing molded
catalyst of the present invention, meaning that the speed of deterioration (coking

deterioration) due to coke precipitation during the reaction is much greater in
comparison with the zeolite-containing molded catalyst of the present invention.
[0124] Thus, in comparison with previously proposed H-type zeolite catalysts, the
zeolite-containing molded catalyst according to the present invention has much better
water heat stability as a fine-particle zeolite. Consequently, it is possible to greatly
control the conventional problems of regeneration degradation and coking
deterioration, and produce aromatic hydrocarbon compounds stably and with high
yield over a long period of time.
[0125] [Table 1] [Raw material composition and reaction yields [% by mass] in
propylene production step]






Industrial Applicability
[0128] The producing process according to the present invention is applicable in
the field of process for producing propylene and aromatic hydrocarbons because it
has the effects of allowing propylene and aromatic hydrocarbons to be efficiently and
stably produced and also allowing changes in the yield structure by easy methods in
the process for producing propylene and aromatic hydrocarbons from a hydrocarbon
feedstock containing olefins.
Brief Description of the.Drawings ^

[0129] Figure 1 shows a schematic view of a producing apparatus according to
one embodiment for implementing the producing process according to the present
invention;
Figure 2 shows a flow sheet illustrating one embodiment of a system used
in the propylene production step of the producing process according to the present
invention; and
Figure 3 shows a flow sheet illustrating another embodiment of a system
used in the propylene production step of the producing process according to the
present invention.
The symbols used in Figure 1 are defined as follows.
1 • • -Producing apparatus according to the present invention, 10- • -Heat exchanger,
12* • -Propylene production reactor, 14- • -Compressor, 16- • -Separator,
18- • -aromatic hydrocarbon production reactor, 20- • -Conduit

WE CLAIM
1. A process for producing propylene and aromatic hydrocarbons,
comprising;
(1) a propylene production step wherein a hydrocarbon feedstock
containing 50 % by mass or more of at least one of C4-12 olefin is brought into contact
in a propylene production reactor with a molded catalyst A containing a first zeolite
fulfilling conditions (i) through (iv) below under a condition in which a partial pressure
of the hydrocarbon feedstock is from 0.05 to 0.3 MPa to thereby perform a catalytic
conversion reaction on the at least one of C4-12 olefin, resulting in a reaction mixture
containing propylene and having a value obtained by dividing an amount of
component [% by mass] of the C6-8 aromatic hydrocarbons by a hydrocarbon partial
pressure [MPa] is 13 or less, the reaction mixture is separated into fraction C
containing mainly hydrogen and C1-3 hydrocarbons and fraction D containing mainly at
least one of C4+ hydrocarbon,, and propylene is isolated from the fraction C:
(i) having a medium pore diameter zeolite with a pore diameter of from 5
to 6.5 A;
(ii) containing substantially no protons;
(iii) containing at least one metal selected from the group consisting of
copper, silver and gold; and
(iv) having an SiO2/ Al2O3 molar ratio of at least 800 but no more than
2,000; and

(2) an aromatic hydrocarbon production step wherein a raw material
containing entirely or partly all or a part of the fraction D is brought into contact in an
aromatic hydrocarbon production reactor with a molded catalyst B containing a
second zeolite fulfilling conditions (v) through (vii) below in a gaseous phase at 650°C
or less:
(v) having a medium pore diameter zeolite with a pore diameter of from 5
to 6.5 A:
(vi) with a primary particle diameter in a range of from 0.02 to 0.25 µm; and
(vii) containing at least one metal element selected from the group
consisting of copper, silver and gold in the form of the corresponding cations.
2. The process as claimed in Claim 1, wherein the hydrocarbon feedstock
containing 50 % by mass or more of at least one of C4-12 olefin which is used in the
propylene production step contains 2.5 % by mass or less of at least one of C3-12 diolefin
compound.
3. Th*e process as claimed in Claim 1, wherein the first zeolite contains silver.
4. The process as claimed in Claim 1, wherein the first zeolite is an MFI zeolite.
5. The process as claimed in Claim 1, wherein, in the propylene production step,
10 % by mass to 95 % by mass of the fraction D is recycled back to the propylene
production reactor and used as part of the hydrocarbon feedstock.

6. The process as_claimed in Claim 1, wherein the fraction C is separated into
fraction C1 containing mainly hydrogen and hydrocarbons of 1-2 carbon atoms and fraction
C2 containing mainly hydrocarbons of 3 carbon atoms, and at least part of the fraction
C1 is recycled back to the propylene production reactor and used as part of the
hydrocarbon feedstock.
7. The process as claimed in Claim 1, wherein the propylene production reactor
is an adiabatic fixed-bed reactor.
8. The process as claimed in Claim 1, wherein a reaction temperature for the
propylene production step is from 500°C to 580°C, and a weight hourly space velocity of the
hydrocarbon feedstock based on a weight of the molded catalyst A is from 2 hr'1 to
20 hr-1.
9. The process as claimed in Claim 1, wherein the molded catalyst B further
contains at least one selected from the group consisting of copper, zinc, gallium, indium,
nickel, palladium and platinum and compounds of these.
10. The process as claimed in Claim 1, wherein the second zeolite contains
silver.
11. The process as claimed in Claim 1, wherein thesecond zeolite is an MFI zeolite.
12 The process as claimed in Claim 1, wherein the aromatic hydrocarbon production
reactor is an adiabatic fixed-bed reactor.

13. The process as claimed in Claim 1, wherein the fraction C is separated into
fraction C1 containing mainly hydrogen and hydrocarbons of 1-2 carbon atoms and fraction
C2 containing mainly hydrocarbons of 3 carbon atoms, and at least part of the fraction C1
is used as part of the hydrocarbon feedstock in the aromatic hydrocarbon production
step.
14. A process for producing propylene and aromatic hydrocarbons, comprising:
(1) a propylene production step wherein a hydrocarbon feedstock containing
50 % by mass or more of at least one of C4-12 olefin is brought into contact in a propylene
production reactor with a molded catalyst A containing a first zeolite fulfilling conditions (i)
through (iv) below under a condition in which a partial pressure of the hydrocarbon
feedstock is from 0.05 to 0.3 MPa to thereby perform a catalytic conversion reaction on the
at least one of C4-12 olefin, resulting in a reaction mixture containing propylene and
having a value obtained by dividing an amount of component [% by mass] of the C6-8
aromatic hydrocarbons by a hydrocarbon partial pressure [MPa] is 13 or less, the reaction
mixture is separated into fraction E containing mainly hydrogen and C1-2 hydrocarbons
and fraction F containing mainly at least one of C3+ hydrocarbon, the fraction F is separated
into fraction F1 containing mainly C3 hydrocarbons and fraction F2 containing mainly at
least one of C4+ hydrocarbon, and propylene is isolated from the fraction F1:
.(i) having a medium pore diameter zeolite with a pore diameter of from
5 A to 6.5 A;
(ii) containing effectively no protons;
(iii) containing at least one metal selected from the group consisting of the
copper, silver and gold; and
(iv) having an SiO2;/ AI2O3 mole ratio of at least 800 but no more than
2,000: and

(2) an aromatic hydrocarbon production step wherein a raw material
containing entirely or partly all or a part of the fraction F2 is brought into contact in an
aromatic hydrocarbon production reactor with a molded catalyst B containing a
second zeolite fulfilling conditions (v) through (vii) below in a gaseous phase at 650°C
or less;
(v) having a medium pore diameter zeolite with a pore diameter of from 5 A
to 6.5 A;
(vi) with a primary particle diameter in the range of from 0.02 µm to
0.25 µm; and
(vii) containing at least one metal element selected from the group
consisting of copper, silver and gold in the form of the corresponding cations.
15. The process as claimed in Claim 14, wherein the hydrocarbon feedstock
containing 50 % by mass or more of at least one of C4-12 olefin which is used in the
propylene production process contains 2.5 % by mass or less of at least one of C3-12 diolefin
compound.
16. The process as claimed in Claim 14, wherein the first zeolite
contains silver.
17. The process as claimed in Claim 14, wherein the first zeolite is an MFI
zeolite.

18. The process as claimed in Claim 14, wherein, in the propylene
production process, 10 % by mass to 95 % by mass of the fraction F2 is recycled back to
the propylene production reactor and used as part of the hydrocarbon feedstock.
19. The process as claimed in Claim 14, wherein at least part of the fraction E
is recycled back into the propylene production reactor and used as part of the hydrocarbon
feedstock.
20. The process as claimed in Claim 14, wherein the propylene production
reactor is an adiabatic fixed-bed reactor.
21. The process as claimed in Claim 14, wherein a reaction temperature for
the propylene production step is from 500°C to 580°C and a weight hourly space
velocity of the hydrocarbon feedstock based on a weight of the molded catalyst A is
from 2 hr-1 to 20 hr-1.
22. The process as claimed in Claim 14, wherein molded the catalyst B
further contains at least one selected from the group consisting of copper, zinc,
gallium, indium, nickel, palladium and platinum and compounds of these.

23. The process as claimed in Claim 14, wherein the second zeolite
contains silver.
24. The process as claimed in Claim 14, wherein the second zeolite is an
MFI zeolite.
25. The process as claimed in Claim 14, wherein the aromatic
hydrocarbon production reactor is an adiabatic fixed-bed reactor.
26. The process as claimed in Claim 14, wherein at least part of the
fraction E is used as part of the hydrocarbon feedstock in the aromatic hydrocarbon
production step.


ABSTRACT

PROCESS FOR PRODUCING PROPYLENE AND AROMATIC HYDROCARBON
It is an object of the present invention to provide an improved process whereby the
yield structure of the components can be varied by a simple method, and the
products can be produced stably and efficiently in a process for producing propylene
and aromatic hydrocarbons from a hydrocarbon feedstock containing C4-12 olefins
using a medium pore diameter zeolite-containing catalyst. A process for producing is
disclosed which comprises a propylene production step wherein a specific zeolite
catalyst is used to remove a C4+ hydrocarbon component from a reaction mixture, and
part of the hydrocarbon component is recycled as necessary without modification, and
an aromatic hydrocarbon production step wherein all or a part of the C4+ hydrocarbon
component is used as the raw material.

Documents:

02385-kolnp-2008-abstract.pdf

02385-kolnp-2008-claims.pdf

02385-kolnp-2008-correspondence others.pdf

02385-kolnp-2008-description complete.pdf

02385-kolnp-2008-drawings.pdf

02385-kolnp-2008-form 1.pdf

02385-kolnp-2008-form 2.pdf

02385-kolnp-2008-form 3.pdf

02385-kolnp-2008-form 5.pdf

02385-kolnp-2008-international publication.pdf

02385-kolnp-2008-international search report.pdf

02385-kolnp-2008-others pct form.pdf

02385-kolnp-2008-pct priority document notification.pdf

02385-kolnp-2008-pct request form.pdf

2385-KOLNP-2008-(13-03-2012)-ABSTRACT.pdf

2385-KOLNP-2008-(13-03-2012)-AMANDED CLAIMS.pdf

2385-KOLNP-2008-(13-03-2012)-DESCRIPTION (COMPLETE).pdf

2385-KOLNP-2008-(13-03-2012)-DRAWINGS.pdf

2385-KOLNP-2008-(13-03-2012)-EXAMINATION REPORT REPLY RECEIVED.pdf

2385-KOLNP-2008-(13-03-2012)-FORM-1.pdf

2385-KOLNP-2008-(13-03-2012)-FORM-2.pdf

2385-KOLNP-2008-(13-03-2012)-OTHERS.pdf

2385-KOLNP-2008-(18-11-2011)-CORRESPONDENCE.pdf

2385-KOLNP-2008-(18-11-2011)-FORM-3.pdf

2385-KOLNP-2008-(18-11-2011)-OTHERS.pdf

2385-KOLNP-2008-(20-04-2012)-ABSTRACT.pdf

2385-KOLNP-2008-(20-04-2012)-AMANDED CLAIMS.pdf

2385-KOLNP-2008-(20-04-2012)-CORRESPONDENCE.pdf

2385-KOLNP-2008-(20-04-2012)-DESCRIPTION (COMPLETE).pdf

2385-KOLNP-2008-(20-04-2012)-DRAWINGS.pdf

2385-KOLNP-2008-(20-04-2012)-FORM-1.pdf

2385-KOLNP-2008-(20-04-2012)-FORM-2.pdf

2385-KOLNP-2008-(20-04-2012)-PA-CERTIFIED COPIES.pdf

2385-KOLNP-2008-CORRESPONDENCE 1.3.pdf

2385-KOLNP-2008-CORRESPONDENCE OTHERS 1.1.pdf

2385-KOLNP-2008-CORRESPONDENCE-1.4.pdf

2385-KOLNP-2008-EXAMINATION REPORT.pdf

2385-KOLNP-2008-FORM 1.1.pdf

2385-KOLNP-2008-FORM 18.pdf

2385-KOLNP-2008-FORM 26.pdf

2385-KOLNP-2008-FORM 3.pdf

2385-KOLNP-2008-FORM 5.pdf

2385-KOLNP-2008-GRANTED-ABSTRACT.pdf

2385-KOLNP-2008-GRANTED-CLAIMS.pdf

2385-KOLNP-2008-GRANTED-DESCRIPTION (COMPLETE).pdf

2385-KOLNP-2008-GRANTED-DRAWINGS.pdf

2385-KOLNP-2008-GRANTED-FORM 1.pdf

2385-KOLNP-2008-GRANTED-FORM 2.pdf

2385-KOLNP-2008-GRANTED-SPECIFICATION.pdf

2385-KOLNP-2008-INTERNATIONAL PUBLICATION.pdf

2385-KOLNP-2008-OTHERS-1.1.pdf

2385-KOLNP-2008-OTHERS.pdf

2385-KOLNP-2008-REPLY TO EXAMINATION REPORT.pdf

2385-KOLNP-2008-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

2385-KOLNP-2008_CORRESPONDENCE 1.2.pdf

2385-KOLNP-2008_PRIORITY DOCUMENT.pdf


Patent Number 253708
Indian Patent Application Number 2385/KOLNP/2008
PG Journal Number 33/2012
Publication Date 17-Aug-2012
Grant Date 14-Aug-2012
Date of Filing 12-Jun-2008
Name of Patentee ASAHI KASEI CHEMICALS CORPORATION
Applicant Address 1-105 KANDA JINBOCHO, CHIYODA-KU, TOKYO
Inventors:
# Inventor's Name Inventor's Address
1 MITSUHIRO SEKIGUCHI 1-2, YURAKU-CHO 1-CHOME CHIYODA-KU, TOKYO 100-8440
2 YOSHIKAZU TAKAMATSU 1-2, YURAKU-CHO 1-CHOME CHIYODA-KU, TOKYO 100-8440
PCT International Classification Number C07C 2/42,C07C 4/06
PCT International Application Number PCT/JP2007/050311
PCT International Filing date 2007-01-12
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2006-008038 2006-01-16 Japan