Title of Invention

"PROCESS FOR THE PRODUCTION OF HYDROCARBON BLENDS WITH A HIGH OCTANE NUMBER BY THE HYDROGENATION OF HYDROCARBON BLENDS CONTAINING BRANCHED OLEFINS"

Abstract A process for the production of hydrocarbon blends with a high octane number by the hydrogenation of hydrocarbon blends, containing C8, C12 and C16 branched olefins, characterized by sending said blends, as such or fractionated into two streams, one containing the C8 branched olefin, the other containing the C12 and C16 branched olefins, to a single hydrogenation zone or to two hydrogenation zones in parallel, respectively, only the stream containing saturated C8 hydrocarbons, obtained by the fractionation of the stream produced by the single hydrogenation zone or obtained by the hydrogenation zone fed by the fractionated stream containing the C8 branched olefin, being at least partly recycled to the single hydrogenation zone or to the hydrogenation zone fed by the fractionated stream containing the C8 branched olefin, and the hydrocarbon blend with a high octane number, obtained by the fractionation of the stream produced from the single hydrogenation zone or obtained from the hydrogenation zone, being fed by the fractionated stream containing the C12 and C16 branched olefins.
Full Text The present invention relates to process for the production of hydrocarbon blends with a high octane number by the hydrogenation of hydrocarbon blends containing branched olefins.
The present invention . relates to a process for the production of hydrocarbon blends with a high octane number by the hydrogenation of hydrocarbon blends containing branched C8, C12 and C16 olefinic cuts, .optionally, obtained by the selective dimerization of hydrocarbon cuts containing isobutene.
Refineries throughout the world are currently in the process of producing "Low Environmental- Impact Fuels (characterized, by a reduced content of aroma tics, olefins,, sulfur and a lower volatility), obviously attempting to minimize the effect of their production on the functioning of the refinery itself.
MTBE and alkylated products are the most suitable compounds for satisfying the future demands of refineries, however the use of MTBE is at present hindered by unfavourable legislative regulations whereas alkylated products have a limited availability.
As a result of the continuous attacks on MTBE, due to
its poor biodegradability and presumed toxicity, this compound
has been banned from fuels in California and in many
other states in the USA (50% approximately of the world
market) ; consequently not only is it difficult to foresee
its use (together with that of other alkyl ethers) in reformulated
fuels in the near future, but rather, the removal
of this ether will create considerable problems for
refineries as, in addition to its high octane function,
MTBE also exerts a diluting action of the most harmful
products for the environment (sulfur, aromatics, benzene,
etc.) .
Alkylated products are undoubtedly ideal compounds for
reformulated fuels as they satisfy all the requisites envisaged
by future environmental regulations as they combine
a high octane number with a low volatility and the practically
complete absence of olefins, aromatics and sulfur.
A further positive aspect of alkylation is that it is
capable of activating isoparaffinic hydrocarbons, such as,
for example, isobutane which binds itself, by reaction in
liquid phase catalyzed by strong acids, with olefins (propylene,
butanes, pentanes and relative blends) producing
saturated C7-C9 hydrocarbons with a high octane number.
Higher productions of alkylated products than those
currently available, however, would require the construetion
of large alkylation units as, due to its scarcity, an
alkylated product does not represent a commodity which is
widely available at present on the market, but forms a component
of gasoline used for captive use in the refineries
which produce it.
This represents a great limitation for the large-scale
use of alkylated products as the construction of new units
is limited by the incompatibility of the catalysts used in
traditional processes (hydrochloric acid and sulfuric acid)
with the new environmental regulations: processes with hydrochloric
due to the dangerous nature of this acid, especially
in populated areas, processes with sulfuric acid as
a result of its highly corrosive capacity as well as the
considerable production of acid mud which is difficult to
dispose of.
Alternative processes with solid acid catalysts are
being developed but their commercial applicability must
still be demonstrated.
In order to face this problem, increasing resort will
have to be made to purely hydrocarbon products, such as
those obtained by the selective dimerization of C3 and C4
olefins, which, as a result of their octane characteristics
(both a high Research Octane Number (RON) and also Motor
Octane Number (MON)) and their boiling point (poor volatility
but low end point) are included in the range of compo-
sitions which are extremely interesting for obtaining gasolines
which are more compatible with current environmental
demands.
Oligomerization (often incorrectly called polymerization)
processes were widely used in refining in the thirties'
and forties' to convert low-boiling C3-C4 olefins
into so-called "polymer" gasoline. Typical olefins which
are oligomerized are mainly propylene, which gives (Cg)
dirtiers or slightly higher oligomers depending on the process
used, and isobutene which mainly gives (C8) dimers but
always accompanied by considerable quantities of higher
oligomers (C=+) .
This process leads to the production of a gasoline
with a high octane number (RON about 97) but also with a
high sensitivity due to the purely olefinic characteristic
of the product (for more specified details on the process
see: J.H. Gary, G.S. Handwerk, "Petroleum Refining: Technology
and Economies'", 3rd Ed., M. Dekker, New York,
(1994), 250). The olefinic nature of the product represents
an evident limit to the process as the hydrogenation of
these blends always causes a considerable reduction in the
octane characteristics of the product, which thus loses its
activity.
If we limit our attention to the oligomerization of
isobutene, it is known that this reaction is generally car-
ried out with acid catalysts such as phosphoric acid supported
on a solid (for example kieselguhr), cationic exchange
acid resins, liquid acids such as H2SO4 or sulfonic
acid derivatives, silico-aluminas, mixed oxides, zeolites,
fluorinated or chlorinated aluminas, etc.
The main problem of dimerization, which has hindered
its industrial development, is the difficulty in controlling
the reaction rate; the high activity of all these
catalytic species together with the difficulty in controlling
the temperature in the reactor, does in fact make it
extremely difficult to limit the addition reactions of isobutene
to the growing chains and consequently to obtain a
high-quality product characterized by a high selectivity to
dimers.
In dimerization reactions, there is in fact the formation
of excessive percentages of heavy oligomers such as
trimers (selectivity of 15-60%) and tetramers (selectivity
of 2-10%) of isobutene. Tetramers are completely outside
the gasoline fraction as they are too high-boiling and
therefore represent a net loss in yield to gasoline; as far
as trimers (or their hydrogenated derivatives) are concerned,
it is advisable to strongly reduce their concentration
as they are characterized by a boiling point (170-
180°C) at the limit of future specifications on the final
boiling point of reformulated gasolines.
In order to obtain a better-quality product by reaching
higher sel activities (content of dinners >80-85% by
weight), it is possible to use different solutions which
can moderate the:: activity of the catalyst and consequently
control the reaction rate:
• oxygenated compounds can be used (tertiary alcohol and/or
alkyl ether and/or primary alcohol) in a substoichiometric
quantity with respect to the isobutene fed
in the charge using tubular and/or adiabatic reactors
(IT-MI95/A001140 of 01/06/1995, IT-MI97/A001129 of
15/05/1997 and IT-MI99/A001765 of 05/08/1999) ;
• tertiary alcohols can be used (such as terbutyl alcohol)
in a sub-stoicliiometric quantity with respect to the isobutene
fed in the charge using tubular and/or adiabatic
reactors (IT-MI94/A001089 of 27/05/1994;
• alternatively, it is possible to suitably modify the
charge by mixing the fresh charge with at least a part of
the hydrocarbon stream obtained after the separation of
the product, so as to optimize the isobutene content ( 20% by weight) and use a linear olef in/isobutene ratio
greater than 3: in this case, the use of reactors such as
tubular or "Boiling Point Reactors" capable of controlling
the temperature increase, is fundamental for obtaining
high selectivities (IT-MI2000/A001166 of 26/05/2000) .
Using these aolutions, it is therefore possible to favour
the dirtier izat ion of isobutene and isobutene/n-butene
co-dimerizations, with respect to the oligomerization, and
avoid the triggering of oligomerization-polymerization reactions
of linear butenes which are favoured by high temperatures
.
The dimerination product is then preferably hydrogenated
to give a completely saturated final product, with a
high octane number and low sensitivity. For illustrative
purposes, the octane numbers and relative boiling points of
some of the products obtained by the dimerization of isobutene
are indicated in the following table.
(Table Removed)
The hydrogenation of olefins is generally effected using
two groups of catalysts:
those based on nickel (20-80% by weight);
those based on noble metals (Pt and/or Pd) supported
on a metal content of 0.1-1% by weight.
The operating conditions used for both groups are
quite similar; in the case of nickel catalysts/ resort must
be made however to a higher hydrogen/olefin ratio as these
catalysts have a greater tendency towards favouring the
cracking of the olefins. Nickel-based catalysts are less
costly but become more easily poisoned in the presence of
sulfurated compounds; the maximum quantity of sulfur they
can tolerate is 1 ppm with respect to approximately 10 ppm
tolerated by catalysts based on noble metals. The selection
of the type of catalyst to be used therefore depends on the
particular charge to be hydrogenated.
A wide range of operating conditions can be adopted
for the hydrogenation of olefins; it is possible to operate
in vapour phase or in liquid phase but operating conditions
in liquid phase are preferred. The reactor configuration
can be selected from adiabatic fixed bed reactors, tubular
reactors, stirred reactors or column reactors, even if the
preferred configuration envisages the use of an adiabatic
reactor which can optionally consist of one or more catalytic
beds (separated by intermediate cooling).
The hydrogen pressure is preferably below 5 MPa, more
preferably between 1 and 3 MPa. The reaction temperature
preferably ranges from 30 to 200°C. The feeding space velocities
of the olefinic streams are preferably lower than
20 h~l, more preferably between 0.2 and 5 h"1. The heat
which develops from the reaction is generally controlled by
diluting the olefinic charge by recycling a part of the hydrogenated
product itself (in a ratio: volume of saturated
product/volume of olefin lower than 15).
The content of residual olefins in the product depends
on the use of the product itself; in the case of
blends deriving from the dimerization of isobutene (which
can be used as components for gasolines) and having the
following average composition
C8 : 80-95% by weight
: 5-20% by weight
: 0.1-2% by weight
a content of residual olefins lower than 1% can be considered
as being acceptable.
The hydrogenation of a cut having this composition is
not a simple operation however, as a series of factors
should be taken into account:
• the hydrogenation rate is inversely proportional to the
chain length; the hydrogenation of C8 olefinic dimers
does in fact require much lower temperatures (100-140°C)
with respect to those necessary for the hydrogenation of
C12 olefins (100-200 °C) . In the case of C16 olefins, even
higher temperatures are obviously necessary. Within the
single fractions, moreover, olefins with a terminal double
bond are the easiest to hydrogenate.
The reaction temperature must consequently be selected so
as to maximize the conversion of Ci2 and C16 olefins; in
any case it is onerous to operate under such conditions
as to completely eliminate these olefins.
• The hydrogenation reaction is extremely exothermic and
consequently to limit the temperature increase in the
adiabatic reactor, the olefinic charge is generally diluted
with the hydrogenated product.
• The most common hydrogenation catalysts (based on nickel
or palladium) tend to become deactivated as a result of
the heavy olefins and various poisons such as sulfurated
compounds. The greater the number of carbon atoms of the
olefins, the slower the hydrogenation kinetics and the
greater possibility there is of these olefins being deposited
on the catalyst forming coke and reducing its activity.
As far as sulfurated compounds are concerned, on
the other hand, the presence of sulfur is practically inevitable
in this type of charge (almost always greater
than 1 ppm and higher in charges from FCC and coking) ,
nickel catalysts are consequently difficult to use
whereas those based on supported noble metals are preferred.
In the case of charges particularly rich in sulfurated
compounds, resort can also be made to bimetallic
catalysts such as those used in hydrotreating reactions,
for example Ni/Co and/or Ni/Mo.
An effective temperature control is consequently the
fundamental point of this type of process. The temperature
in the reactor must in fact be kept sufficiently high to
kinetically sustain the hydrogenation of heavy olefins but
at the same time an excessive increase must be avoided (due
to the exothermicity of the reaction) which can activate
possible cracking phenomena of the olefins or degeneration
of the catalyst (sintering of the metal) .
The temperature control in the reactor is generally
effected by diluting the olefinic charge with the hydrogencited
product (in ratios generally ranging from 0.5 to 20)
and figure I indicates a classical hydrogenation scheme.
The stream (I) containing isobutene, for example coming
from Steam-Cracking or Coking or FCC units or from the
Dehydrogenation of isobutane, is sent to the reactor (Rl)
in which the isobutene is selectively converted to dimers.
The effluent- (2) from the reactor is sent to a separation
column (Cl) where a stream (3) essentially containing
the non-converted isobutene, linear olefins and saturated
C4 products (n-butane and isobutane) is removed at the
head, whereas an olefinic stream (4) consisting of dimers
and higher oligomers is removed from the bottom, and is fed
to the hydrogenation reactor (R2) together with the saturated
product (5) and hydrogen (6) . The effluent from the
reactor (7) is sent to a stabilizing column (C2) from which
non-converted hydrogen (8) is recovered at the head whereas
the hydrogenated product (9) is obtained at the bottom. A
part of this stream (10) leaves the plant whereas the re-
maining stream is recycled to the reactor.
This plant configuration is valid in the case of the
hydrogenation of a single olefinic species (conversions
higher than 99%) but may not be effective when, as in the
case of the dimerization product of isobutene, there are
olefins with hydrocarbon chains and very different reaction
rates. In this case, in fact, the difficulty in completely
converting the Ci2 and Ci6 olefins negatively influences the
feasibility of the whole process; if, in fact, the hydrogenation
of G12 and Cis olefins is not complete, they are
recycled to the reactor with a doubly negative effect:
the tendency of accumulating in the product until it
is sent outside specification (total olefins >1% by
weight);
a reduction in the life of the catalyst as these olefins
are those which have the greatest tendency to become
deposited on the catalyst creating carbonaceous
deposits and thus reducing the activity.
An analogous situation can also be caused by the
presence of possible poisons (such as sulfurated compounds)
which are not completely converted in the hydrogenation reactor.
We have now found a process which is economically
more advantageous with respect to a conventional hydrogenation,
which envisages the recycling of the whole C8-C16
fraction to the reactor, as it is possible to use less
drastic reaction conditions and prolong the life of the
catalyst.
The process, object of the present invention, for the
production of hydrocarbon blends with a high octane number
by the hydrogenation of hydrocarbon blends, containing
branched C8, C12 and C16 olefinic cuts, is characterized by
sending said blends, as such or fractionated into two
streams, one substantially containing the branched C8 olefinic
cut, the other substantially containing the branched
C12 and C16 olefinic cuts, to a single hydrogenation zone or
to two hydrogenation zones in parallel, respectively,
only the stream substantially containing saturated C8 hydrocarbons,
obtained by the fractionation of the stream
produced by the single hydrogenation zone or obtained by
the hydrogenation zone fed by the fractionated stream substantially
containing the branched Ca olefinic cut, being
at least partly recycled to the single hydrogenation zone
or to the hydrogenation zone fed by the fractionated stream
substantially containing the branched C8 olefinic cut, and
the hydrocarbon blend with a high octane number, obtained
by the fractionation of the stream produced from the single
hydrogenation zone or obtained from the hydrogenation zone,
being fed by the fractionated stream substantially containing
the branched C12 and C16 olefinic cuts.
The C8, CL2 and C16 olefinic cuts contained in the hydrocarbon
blends to be treated are preferably oligomers of
isobutene, which can derive from the dimerization of isobutene.
In addition to said olefinic cuts, the hydrocarbon
blends to be treated can also contain C12 and C16 and branched
C12 and C16 olefinic cuts in lower quantities.
In particular, blends substantially consisting of
branched C12 and C16 olefins are preferably processed according
to the invention, wherein branched C12 olefins range from 3
to 20% by weight, branched ds olefins range from 0.5 to 5%
by weight, the remaining percentage being branched Ca olefins
When two hydrogenation zones in parallel are adopted,
it is advisable for part of the stream substantially containing
saturated CB hydrocarbons, obtained from the hydrogenation
zone fed by the fractionated stream substantially
containing the branched Ca olefinic cut, to be sent to the
hydrogenation zone fed by the fractionated stream substantially
containing the branched C12 and C16olefinic cuts.
The present invention can be effected by fractionating
the high-octane blend either when it is in olefinic
form or in hydrogenated form and in both cases its application
makes the hydrogenation step of C12 and C16 olefinic streams
technically much simpler.'
It is in fact possible to use much blander reaction
conditions as there is no longer the necessity of having to
maximize the conversion, furthermore the life of the catalyst
can be prolonged due to the fact that the heavy hydrocarbons
and possible residual olefins are not recycled to
the reactor.
More specifically, the process according to the invention
in the case of fractionation of the blend in olefinic
form, can comprise the following steps:
a) dirnerizing the isobutene contained in a C4 cut (FCC,
Coking, Steam-Cracking, Dehydrogenation of isobutane);
b) sending the product leaving the dimerization reactor
to a first distillation column from whose head the C4
products are recovered, together with, as side cut, a
stream rich in branched Ca olefins and as bottom
product a stream rich in branched Ci2 and C16 olefins;
c) hydrogenating, in a first reactor, the stream rich in
branched C8 olefins, obtained as side cut, with suitable
catalysts using a part of the C8 products themselves
already saturated to dilute the olefinic
charge;
d) hydrogenating with suitable catalysts, in a second
reactor, the stream rich in branched C12 and C16 olefins
together with the remaining part of the already
15
saturated Ca products, obtaining a saturated highoctane
hydrocarbon blend.
If the quantity of C8 products sent to the second reactor
is kept equal to that of those removed as side cut of
the column, it is possible to have a hydrogenated product
having the same distribution as the hydrocarbons (selectivity
to C8) of the olefinic product leaving the dimerization
step.
The stream rich in branched C8 olefins removed as side
cut can be substantially free of hydrocarbon compounds
higher than Ca.
A simplified process scheme is shown in figure 2 to
illustrate this case more clearly.
The C4 stream (1) containing isobutene is sent to the
reactor (Rl) in which the isobutene is selectively converted
to dimers. The effluent (2) from the reactor is sent
to a separation column (Cl) where a stream (3) essentially
containing the non-converted isobutene, linear olefins and
saturated C4 products (n-butane and isobutane) is removed
at the head, C8 olefins (4) are recovered as side cut
whereas a stream (5) in which the higher oligomers (C12 and C16-
are concentrated, is removed at the bottom.
The side cut (4) is sent to the first hydrogenation
reactor (R2) together with a part of the saturated C8 products
(8) and fresh hydrogen (7) . The remaining part of the
saturated CB products arid fresh hydrogen (11) is sent, on
the other hand, to a second hydrogenabion reactor (R3) together
with fresh hydrogen (6) and the olefinic stream rich
in heavy hydrocarbons (5) . The stream (13) which is obtained
at the outlet of the reactor forms the plant product
.
When, on the other hand, it is the hydrogenated blend
which is fractionated, the process according to the invention
can comprise the following steps:
a) dimerizing the isobutene contained in a C4 cut (FCC,
Coking, Steam-Cracking, Dehydrogenation of isobutarie) ;
b) sending the product leaving the dimerization reactor
to a first distillation column from whose head the C4
products are recovered, whereas the CB-C1S olefinic
blend is recovered from the bottom;
c) hydrogenabing the C12 and C16olefinic blend with suitable,
catalysts using a saturated hydrocarbon stream to dilute
the olefinic charge;
d) sending the: hydrogenation product to one or more distillation
c'olumns where the excess hydrogen is recovered,
together with a saturated stream rich in Cs olefj.
ns, which, is recycled to the hydrogenation reactor,
and a high-octane hydrocarbon blend (which can also
contain C12 olef iris) .
The saturated stream rich in C8 olefins recycled to
the reactor, can be substantially free of hydrocarbon compounds
higher than Ca.
The saturated stream rich in Ca olefins, which is recycled
to the hydrogenation reactor, is in a weight ratio
preferably ranging from 0.1 to 10 with respect to the olefinic
stream at the inlet of the hydrogenation reactor.
A simplified process scheme is shown in figure 3 to
illustrate this new configuration more clearly.
The C4 stream (1) containing isobutene is sent to the
reactor (Rl) in which the isobutene is selectively converted
to dimers. The effluent (2) from the reactor is sent
to a separation column (Cl) where a stream (3) essentially
containing the non-converted isobutene, linear olefins and
saturated C4 products (n-butane and isobutane) is removed
at the head, whereas a stream (4) consisting of dimers and
higher oligomers is removed at the bottom.
The bottom stream (4) is sent to the hydrogenation reactor
(R2) together with the stream of recycled product (9) and
fresh hydrogen (5) . The effluent from the reactor (7) is
then sent to a second distillation column (C2) from which
the non-converted hydrogen (10) is recovered from the top,
the product containing heavy C12 and C16 hydrocarbons (8)
from the bottom and as side cut, a pure Ca stream (9) which
is recycled to the reactor R2.
Optionally, for the separation of the effluent of the
hydrogenation reactor, a solution which envisages the use
of two distillation columns, can be used.
In both configurations, the hydrogenation catalysts
adopted are preferably based on nickel or noble metals.
Some examples are provided for a better illustration
of the invention, but which should in no way be considered
as limiting its scope.
EXAMPLE 1
This example illustrates a possible process application
of the present invention. A hydrocarbon fraction, obtained
by the selective dimerization of isobutene and having
the following composition:
C8 olefins 90.0% by weight
C12 olefins 9.5% by weight
C16 olefins 0.5% by weight
is sent to a hydrogenation reactor (adiabatic with intermediate
cooling) together with a stream consisting of saturated
Ca hydrocarbons (in a ratio of 1:1) and a stream of
hydrogen.
Using a commercial catalyst based on supported palladium
and operating in liquid phase with a space velocity of
1 h"1 (volumes of olefin with respect to the volume of
catalyst per hour) , a hydrogen pressure of 3 MPa and an
initial temperature of 140°C, the following conversions can
be obtained, per passage:
Conv. C8 olefins 99.9%
Conv. Ci2 olefins 93.0%
Conv. C16 olefins 60.0%
Conv. total olefins 99.1%
The reaction effluent is then sent to a distillation
column from whose head the excess hydrogen is recovered, as
side cut, a saturated C8 stream (Cia whereas the reaction product is recovered at the bottom.
Operating under these conditions, it is possible to obtain
a hydrogenated product with a content of residual olefins
lower than 1% by weight.
EXAMPLE 2
This examples illustrates another possible use of the
process of the present invention which comprises the fractionation
of the olefinic stream. A hydrocarbon fraction,
obtained by the selective dimerization of isobutene and
having the following composition:
C8 olefins 90.0% by weight
olefins 9.5% by weight
olefins 0.5% by weight
is sent to a fractionation column where the following two
fractions are separated:
Head (86%) C8 olefins 99.5%
C12 olefins 0.5%
Bottom (14%) C8 olefins 28.6%
- 20 -
C12 olefins 67.9%
C16 olefins 3 .5%
The C8 olefins collected at the head (86% of the total
olefins) are sent to a first hydrogenation reactor (adiabatic
with intermediate cooling) together with a stream
consisting of saturated C8 products (in a ratio of 1:1) and
a stream of hydrogen.
Using a commercial catalyst based on supported palladium
and operating in liquid phase with a space velocity of
2 h"1, a hydrogen pressure of 3 MPa and an initial temperature
of 130°C, 95% of the Ca olefins are converted, per
passage.
The bottom product of the column is joined to the remaining
part of hydrogenated C8 products (equal in mass to the olefins
removed at the head of the column so as to have a final
stream still with a total of 90% of C8 hydrocarbons)
and sent to a second hydrogenation reactor where, using a
commercial catalyst based on supported palladium and operating
in liquid phase with a space velocity of 1 h'1, a hydrogen
pressure of 3 MPa and a temperature of 140°C, the
following conversions can be obtained, per passage:
Conv. Ca olefins 99.9%
Conv. Ci2 olefins 93.0%
Conv. Cie olefins 60.0%
Conv. total olefins 95.5%
Operating under these conditions, it is possible to
obtain a hydrogenated product with a content of residual
olefins lower than 1% by weight.
EXAMPLE 3 (comparative)_
This example shows how, using a classical hydrogenation
scheme, it is necessary to resort to much more drastic
reaction conditions to completely eliminate the olefins
from the product. In this case, in fact, in order to control
the reaction heat, a part of the product is recycled
to the reactor and consequently the content of residual
olefins must be minimized.
The hydrogenation of the olefinic blend, whose composition
is the same as Examples 1 and 2, is always carried
out in liquid phase with a commercial catalyst based on
supported palladium, a hydrogen pressure of 3 MPa but with
a space velocity of 0.5 h"1, and a temperature of 150°C,
necessary for obtaining conversions of Ci2 and C1S olefins
of over 99%.
In this case, the process is much less economical with
respect to the previous examples (greater quantity of catalyst
and higher temperatures).











WE CLAIM:
1. A process for the production of hydrocarbon blends with a high octane number by the
hydrogenation of hydrocarbon blends, containing C8, C12 and C16 branched olefins,
characterized by sending said blends, as such or fractionated into two streams, one
containing the C8 branched olefin, the other containing the C12 and C16 branched olefins, to
a single hydrogenation zone or to two hydrogenation zones in parallel, respectively, only the
stream containing saturated C8 hydrocarbons, obtained by the fractionation of the stream
produced by the single hydrogenation zone or obtained by the hydrogenation zone fed by
the fractionated stream containing the C8 branched olefin, being at least partly recycled to
the single hydrogenation zone or to the hydrogenation zone fed by the fractionated stream
containing the C8 branched olefin,
and the hydrocarbon blend with a high octane number, obtained by the fractionation of the stream produced from the single hydrogenation zone or obtained from the hydrogenation zone, being fed by the fractionated stream containing the C12 and C16 branched olefins.
2. The process as claimed in claim 1, wherein the C8, C12 and C16 branched olefins are oligomers of isobutene.
3. The process as claimed in claim 2, wherein the C8, C12 and C16 branched olefins, oligomers of isobutene, derive from the dimerization of isobutene.
4. The process as claimed in claim 1, wherein the hydrocarbon blends containing C8, C12 and C16 branched olefins also contain C9-C11 and C13-C15 branched olefins, in a smaller quantity.
5. The process as claimed in claim 1, wherein part of the stream containing saturated C8
hydrocarbons, obtained from the hydrogenation zone fed by the fractionated stream containing C8 branched olefin, is sent to the hydrogenation zone fed by the fractionated stream containing the C12 and C16 branched olefins.
6. The process as claimed in claims 1 to 3, comprising the following steps:
a) dimerizing the isobutene contained in a C4 cut;
b) sending the product leaving the dimerization reactor to a first distillation column from whose head the C4 products are recovered, together with, as side cut, a stream rich in branched C8 olefins and as bottom product a stream rich in branched
C12 and C16 olefins;
c) hydrogenating, in a first reactor, the stream rich in branched C8 olefins, obtained as side cut, with suitable catalysts using a part of the same C8 products already saturated to dilute the olefinic charge;
d) hydrogenating with suitable catalysts, in a second reactor, the stream rich in branched C12 and C16 olefins together with the remaining part of the already saturated C8 products, obtaining a saturated high-octane hydrocarbon blend.

7. The process as claimed in claims 1 and 6, wherein the stream rich in branched C8 olefins removed as side cut is free of hydrocarbon compounds higher than C8.
8. The process as claimed in claims 1 and 3, comprising the following steps:

a) dimerizing the isobutene contained in a C4 cut;
b) sending the product leaving the dimerization reactor to a first distillation column from whose head the C4 products are recovered, whereas the C8-C16 olefinic blend is recovered from the bottom;

c) hydrogenating the C8-C16 olefinic blend with suitable catalysts using a saturated
hydrocarbon stream to dilute the olefinic charge;
d) sending the hydrogenation product to one or more distillation columns where the
excess hydrogen is recovered, together with a saturated stream rich in C8 olefins,
which is recycled to the hydrogenation reactor, and a high-octane hydrocarbon
blend.
9. The process as claimed in claims 1 and 8, wherein the saturated stream rich in C8
products recycled to the hydrogenation reactor, is in a weight ratio ranging from 0.1 to 10
with respect to the olefinic stream at the inlet of the hydrogenation reactor.
10. The process as claimed in claims 1 and 8, wherein the saturated stream rich in C8 products recycled to the reactor, is free of hydrocarbon compounds higher than C8.
11. The process as claimed in claim 6 or 8, wherein the hydrogenation catalysts are based on nickel or noble metals.
12. The process as claimed in claim 1, wherein the blends consist of branched C8-C16
olefins, wherein the branched C12 olefins range from 3 to 20% by weight, the branched
C16 olefins range from 0.5 to 5% by weight, the remaining percentage being the branched
C8 olefins.

Documents:

1788-DELNP-2006-Abstract-(11-02-2010).pdf

1788-delnp-2006-abstract.pdf

1788-delnp-2006-assignment.pdf

1788-DELNP-2006-Claims-(11-02-2010).pdf

1788-delnp-2006-claims.pdf

1788-delnp-2006-correpondence-others.pdf

1788-DELNP-2006-Correspondence-Others (11-02-2010).pdf

1788-DELNP-2006-Correspondence-Others- (03-03-2010).pdf

1788-DELNP-2006-Correspondence-Others-(03-03-2010).pdf

1788-DELNP-2006-Correspondence-Others-(19-02-2010).pdf

1788-delnp-2006-correspondence-others-1.pdf

1788-DELNP-2006-Description (Complete)-(11-02-2010).pdf

1788-delnp-2006-description (complete).pdf

1788-DELNP-2006-Drawings-(11-02-2010).pdf

1788-delnp-2006-drawings.pdf

1788-DELNP-2006-Form-1-(11-02-2010).pdf

1788-delnp-2006-form-1.pdf

1788-delnp-2006-form-18.pdf

1788-DELNP-2006-Form-2-(11-02-2010).pdf

1788-delnp-2006-form-2.pdf

1788-DELNP-2006-Form-3-(19-02-2010).pdf

1788-delnp-2006-form-3.pdf

1788-delnp-2006-form-5.pdf

1788-DELNP-2006-GPA-(11-02-2010).pdf

1788-delnp-2006-gpa.pdf

1788-delnp-2006-pct-101.pdf

1788-delnp-2006-pct-210.pdf

1788-delnp-2006-pct-220.pdf

1788-delnp-2006-pct-237.pdf

1788-delnp-2006-pct-304.pdf

1788-delnp-2006-pct-308.pdf

1788-DELNP-2006-Petition 137-(19-02-2010).pdf

1788-DELNP-2006-Petition 138-(19-02-2010).pdf

abstract.jpg


Patent Number 240952
Indian Patent Application Number 1788/DELNP/2006
PG Journal Number 25/2010
Publication Date 18-Jun-2010
Grant Date 10-Jun-2010
Date of Filing 03-Apr-2006
Name of Patentee SNAMPROGETTI S.P.A.
Applicant Address VIALE DE GASPERI, 16, I-20097 SAN DONATO MILANESE, ITALY
Inventors:
# Inventor's Name Inventor's Address
1 ROBERTO CATANI SAN VENERIO 5/D, I-20097 SAN DONATO MILANESE, ITALY.
2 MARCO DI GIROLAMO I MAGGIO 7/N, I-20097 SAN DONATO MILANESE, ITALY
3 MASSIMO CONTE CUPELLO 9B, I-20097 SAN DONATO MILANESE, ITALY
4 AMBROGIO GUSBERTI VERDI 36, I-27039 SANNAZZARO DE' BURGUNDI, ITALY
PCT International Classification Number C10G 45/00
PCT International Application Number PCT/EP2004/011362
PCT International Filing date 2004-10-06
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 MI2003A001951 2003-10-10 Italy