Title of Invention

PROCESS FOR SEPARATING NITROGEN GAS BY MOLECULAR SIEVE CARBON

Abstract This invention relates to a process for separating nitrogen, wherein a feed gas made up mainly of nitrogen is fed under pressure to one of at least two adsorption columns packed with molecular sieve carbon to conduct high pressure adsorption, the one of at least two adsorption columns having completed high pressure adsorption is subjected to low pressure desorption, and the alternating cycle of the high pressure adsorption and the low pressure desorption are repeated in each adsorption column to separate nitrogen gas product, wherein the molecular sieve carbon is obtained by adjusting pore size by heat treating charred coconut shell in an inert gas atmosphere and has 0.7 wt% or less ignition residue, and the following relationships (I) and (II) are satisfied: (1) In C < 0.325 + 5.14 x In {(0.64 + 0.098)} x Q/(P + 0.098)} (I) (2) In U < 2.124 - 0.135 x In C (II) where C indicates an oxygen level (ppm) in the nitrogen gas product; Q indicates a volume of nitrogen gas produced per minute per unit effective volume of a single adsorption column; P indicates an adsorption pressure (MPa); and U indicates a ratio of the volume of the feed air to the volume of the nitrogen gas produced.
Full Text DESCRIPTION
PROCESS FOR SEPARATING NITROGEN GAS
AND MOLECULAR SIEVE CARBON
TECHNICAL FIELD
[0001]
The present invention relates to a process for
separating nitrogen gas and to a molecular sieve carbon
for use in such a process. More specifically, the present
invention relates to a process for separating nitrogen and
to a molecular sieve carbon for use in such a process,
wherein a feed gas made up mainly of nitrogen is fed under
pressure to one of at least two adsorption columns packed
with molecular sieve carbon to conduct high pressure
adsorption, the one of at least two adsorption columns
having completed high pressure adsorption is subjected to
low pressure desorption, and the alternating cycle of the
high pressure adsorption and the low pressure desorption
are repeated in each adsorption column to separate
nitrogen gas product, wherein
the molecular sieve carbon has 0.7wt% or less
ignition residue and the following relationships (I) and
(II) are satisfied:
(1) InC (2) InU
where C indicates an oxygen level (ppm) in the nitrogen
gas product; Q indicates a volume of nitrogen gas produced
per minute per unit effective volume of a single
adsorption column; P indicates an adsorption pressure
(MPa); and U indicates a ratio of the volume of the feed
air to the volume of the nitrogen gas produced.
BACKGROUND ART
[0002]
Nitrogen gas has been increasingly used in many
fields, including treatment of metals, production of
semiconductors and a sealing gas in chemical industry.
Pressure swing adsorption (referred to as "PSA",
hereinafter) is one of the most commonly used techniques
in the production of nitrogen gas. In many cases, the
technique is used to separate nitrogen from pressurized
air and involves the use of porous carbon materials such
as molecular sieve carbon. When the feed gas is air, two
or more adsorption columns packed with molecular sieve
carbon are generally used. The air is fed under pressure
to one of the columns to cause oxygen to be adsorbed onto
the molecular sieve, letting the unadsorbed nitrogen flow
out of the column for collection. Meanwhile, the pressure
in the other column is reduced to cause the adsorbed
oxygen to be desorbed. The adsorption and desorption of

oxygen are alternated in the multiple columns. In this
manner, nitrogen can be continuously collected by taking
advantage of the difference in the adsorption rate between
oxygen and nitrogen.
[0003]
Referring to Fig. 1, a conventional PSA process is
described wherein this process uses two adsorption columns
to remove oxygen from air or other gas mixtures composed
mainly of nitrogen, thus giving nitrogen as a gas product
and regeneration of an adsorbent under normal pressure.
In an adsorption step in a adsorption column 4, a feed gas,
such as air, is introduced via a feed gas inlet line 1
into a compressor 2 where it is compressed; and the
compressed air is passed through a cooler 3 into the
adsorption column 4. Each adsorption column is packed
with molecular sieve carbon to serve as the adsorbent. In
the adsorption column, oxygen in the feed gas is
preferentially adsorbed onto the adsorbent and removed
from the feed gas, allowing the remaining nitrogen to flow
through to a product reservoir 6, from which the nitrogen
is collected via a gas product line 16.
[0004]
When one of the adsorption columns is operated in
the adsorption step, the other is operated in the
desorption step and is open to the atmosphere.

Specifically, valves 7, 10 and 12 are opened and valves 8,
9, 11, 13 and 14 are closed when the adsorption column 4
is operated in the adsorption step. Part of the gas that
flows out of the adsorption column 4 flows through an
orifice 15 into the other column operating in the
desorption step and purges the column.
[0005]
After a predetermined period of time, the valves 7,
10 and 12 are closed. In the next pressure equalization
step, the valves 11 and 14 are opened to release the
residual pressure inside the adsorption column 4 into the
adsorption column 5. Subsequently, the valves 8, 9 and 13
are opened and the valves 7, 10, 11, 12 and 14 are closed,
so that the adsorption column 5 switches to adsorption
step and the adsorption column 4 switches to desorption
step. Once the adsorption in the adsorption column 5
comes to an end, the valves 8, 9 and 13 are closed and the
valves 11 and 14 are opened to release the residual
pressure inside the adsorption column 5 into the
adsorption column 4, thereby equalizing the pressure in
the system. This sequence operations are repeated
cyclically to produce nitrogen product.
[0006]
These valves are automatically opened or closed at
the timings set by a timer, so that the nitrogen product

is stored in the product reservoir 6 from which it is
drawn out through the product gas outlet line 15 and is
consumed. The gas (oxygen) adsorbed onto the molecular
sieve carbon is desorbed as the pressure in the columns is
reduced: once the valve 9 or 10 is opened, the adsorbed
gas is released from the molecular sieve carbon and is
discharged from the discharge line 17.
[0007]
There are two ways to make PSA an industrially more
advantageous process: to improve the separation
performance of molecular sieve carbon or to improve the
efficiency of PSA system. Of many PSA processes that have
been proposed thus far, few have taken into account both
of these two approaches. In one process for making
improved molecular sieve carbon, a hydrocarbon such as
toluene is added to coke and the coke is processed at a
high temperature. This causes carbon to be deposited
within the pores of coke and as a result, the size of the
pores is optimized. This improved molecular sieve is used
to remove oxygen from the air to produce nitrogen gas
(Patent Document 1).
Patent Document 1: Japanese Examined Patent Publication No.
Sho 52-18675).
[0008]
In another process, coconut shell carbon powder is

granulated using a coal tar pitch binder and is carbonized.
The granules are washed with hydrochloric acid, and
impregnated with coal tar pitch. The carbonized carbon is
then heated to make a molecular sieve carbon. This
molecular sieve carbon is used to produce nitrogen gas
from the air (Patent Document 2).
Patent Document 2: Japanese Examined Patent Publication No.
Sho 61-8004
[0009]
In still another process, coconut shell carbon
powder is similarly formed into granules using a coal tar
pitch binder. The granules are washed with hydrochloric
acid, and impregnated with creosote oil. The carbonized
carbon is then heated to make a molecular sieve carbon.
This molecular sieve carbon is used to produce nitrogen
gas from the air (Patent Document 3).
Patent Document 3: Japanese Examined Patent Publication No.
Hei 5-66886
[0010]
On the other hand, some PSA processes focus on
improving the efficiency of the process by modifying the
design of the system. One such system uses a molecular
sieve carbon with specifically defined performance and is
designed such that the time at which the exhaustion valve
is opened during the regeneration step under atmospheric

pressure and the time at which the nitrogen gas product is
passed through the adsorption columns are controlled to
satisfy a predetermined relationship. The performance of
the molecular sieve carbon is defined by determining the
ability of the molecular sieve to adsorb oxygen or
nitrogen. Specifically, this is done by leaving the
molecular sieve in the presence of each gas alone under
pressure for 1 minute and determining the ratio of the
volumes of oxygen and nitrogen adsorbed by the molecular
sieve (Patent Document No. 4).
Patent Document 4: Japanese Patent No. 2619839
[0011]
Another such system uses a molecular sieve carbon
with its performance defined by determining its ability to
adsorb oxygen or nitrogen. Likewise, the performance is
determined by leaving the molecular sieve in the presence
of oxygen or nitrogen alone under pressure for 1 minute
and determining the ratio of the volumes of oxygen and
nitrogen adsorbed by the molecular sieve. In this system,
the product nitrogen gas amount taken out and the
effective volume of the product storage tank are
controlled so as to be correlated to the effective volume
per one adsorbing tower, and the time required for the
adsorption step is specified(Patent Document 5).
Patent Document 5: Japanese Patent No. 2623487

[0012]
These improved PSA systems may be used in
conjunction with any of the modified molecular sieve
carbons to make the PSA process even more suitable for
industrial applications. To this end, it is necessary to
design small PSA systems that require minimum amounts of
molecular sieve carbon and feed air.
[0013]
Recently, a PSA system in which the pressure rise
rate at the pressurizing step and the time at the
pressure-equalizing step are controlled is developed.
This facilitates effective generation of highly pure
nitrogen gas (Patent Document 6). Another PSA system
achieves improved separation performance by using a
cylindrical molecular sieve carbon that is 0.5 to 1.5 mm
in height (Patent Document No. 7).
Patent Document 6: Japanese Patent Application Laid-Open
No. 2001-342013
Patent Document 7: Japanese Patent Application Laid-Open
No. 2003-104720
DISCLOSURE OF THE INVENTION
[0014]
The PSA systems described in Patent Documents 6 and
7 each enable effective separation of nitrogen gas and are

each a relatively advanced system. However, the PSA
system of Patent Document 6 has a drawback in that it
still requires a substantial volume of molecular sieve
carbon, though the volume of air used has been
sufficiently reduced. The PSA system of Patent Document 7
on the other hand has a problem that, despite the large
volume of nitrogen produced by each molecular sieve carbon,
the air consumption by the system is significantly large,
making the system industrially unattractive.
[0015]
Thus, no PSA systems have ever been developed that
meet the two essential requirements for an industrially
viable PSA process: small volume of molecular sieve carbon
and small volume of feed air. It is therefore an object
of the present invention to provide an industrially viable
PSA process that requires small volumes of molecular sieve
carbon and feed air.
MEANS TO SOLVE THE PROBLEMS
[0016]
To achieve the above-mentioned objective, the
present inventor have closely examined previously reported
PSA processes and have discovered that for the development
of industrially viable PSA processes, it is necessary to
use a molecular sieve carbon that has 0.7 wt% or less

ignition residue. The present inventor have also
discovered that the oxygen level in the nitrogen gas
product, the volume of the nitrogen gas produced per
minute per unit effective volume of a single adsorption
column, and the adsorption pressure are closely related to
one another, as are the ratio of the volume of the feed
air to the volume of the nitrogen gas product and the
oxygen level in the nitrogen gas product: These quantities
must satisfy a particular relationship. These findings
ultimately led to the present invention.
[0017]
Accordingly, the present invention in one aspect
provides a process for separating nitrogen, wherein a feed
gas made up mainly of nitrogen is fed under pressure to
one of at least two adsorption columns packed with
molecular sieve carbon to conduct high pressure adsorption,
the one of at least two adsorption columns having
completed high pressure adsorption is subjected to low
pressure desorption, and the alternating cycle of the high
pressure adsorption and the low pressure desorption are
repeated in each adsorption column to separate nitrogen
gas product, wherein
the molecular sieve carbon has 0.7wt% or less
ignition residue and the following relationships (I) and
(II) are satisfied:

(1) InC (2) InU where C indicates an oxygen level (ppm) in the nitrogen
gas product; Q indicates a volume of nitrogen gas produced
per minute per unit effective volume of a single
adsorption column; P indicates an adsorption pressure
(MPa); and U indicates a ratio of the volume of the feed
air to the volume of the nitrogen gas produced.
[0018]
In another aspect, the present invention provides a
molecular sieve carbon with a ignition residue of 0.7% or
less, wherein; when a feed gas made up mainly of nitrogen
is fed under pressure to one of at least two adsorption
columns packed with the molecular sieve carbon to conduct
high pressure adsorption, the one of at least two
adsorption columns having completed high pressure
adsorption is subjected to low pressure desorption, and
the alternating cycle of the high pressure adsorption and
the low pressure desorption are repeated in each
adsorption column to separate nitrogen gas; the molecular
sieve carbon satisfies the following relationships (I')
and (II'):
(1) InC (2) InU where C indicates an oxygen level (ppm) in the nitrogen

gas product; Q indicates a volume of nitrogen gas produced
per minute per unit effective volume of a single
adsorption column; P indicates an adsorption pressure
(MPa); and U indicates a ratio of the volume of the feed
air to the volume of the nitrogen gas produced.
ADVANTAGES OF THE INVENTION
[0019]
According to the present invention, there is
provided an industrially viable PSA process that requires
small volumes of molecular sieve carbon and feed air. The
PSA process of the present invention can produce highly
pure nitrogen with decreased volumes of molecular sieve
carbon and feed air and thus serves as a cost effective
PSA technique.
BEST MODE FOR CARRYING OUT THE INVENTION
[0020]
The most significant feature of the process of the
present invention for separating nitrogen gas is the use
of the molecular sieve carbon that has 0.7 wt% or less
ignition residue and satisfies the following relationships
(I) and (II):
(1) InC (2) InU
where C indicates the oxygen level (ppm) in the nitrogen
gas product; Q indicates the volume of nitrogen gas
produced per minute per unit effective volume of a single
adsorption column; P indicates the adsorption pressure
(MPa); and U indicates the ratio of the volume of the feed
air to the volume of the nitrogen gas produced.
[0021]
It is more preferred that InC satisfies the
following relationship (III):
InC [0022]
The molecular sieve carbon used to pack the
adsorption columns in the process for separating nitrogen
gas of the present invention has superfine pores sized 3
to 5 angstroms. Such molecular sieve carbons are produced
by charring charcoal, coal, coke, coconut shell, resin,
pitch or other materials having uniformly sized fine pores
to make plant-based, coal-based, resin-based or pitch-
based carbon material, decalcifying the carbon material,
and adjusting the pore size of the decalcified carbon
material. Plant-based carbon materials are particularly
preferred for ease of decalcification. Of different
plant-based carbon materials, coconut shell is
particularly preferred.
[0023]

Plant-based carbon materials such as coconut shell
generally contain 2.0wt% or more ash. In order to use
coconut shell or other plant-based carbon materials in the
present invention, their ash content must be reduced to
0.7 wt% or less. Though the ash content of these
materials may be reduced by any suitable technique, it is
preferred to repeatedly wash them with hydrochloric acid.
The term "0.7 wt% or less ash" as used herein means the
amount of ash remaining in the molecular sieve carbon
after pore size adjustment of the carbon materials that
are materials of active carbon. Once the ash content has
been reduced to 0.7wt% or less, the pore size is adjusted
to obtain molecular sieve carbon suitable for use in the
present invention.
[0024]
The adsorption time is typically set to the range of
2 0 sec to 12 0 sec, and more preferably over the range of
40 sec to 70 sec. Although the shape of the molecular
sieve carbon may not be restricted, spheres or cylinders
(pellets) that are 0.4 to 1.5 mm in outer diameter (D) are
practically preferred. When the molecular sieve carbon is
formed as cylinder, it is typically formed such that the
ratio of the length of the cylinder (L) to the outer
diameter (D) thereof is from about 2 to about 5.
[0025]

The molecular sieve carbon for use in the process of
the present invention may be prepared in the following
manner: Coconut shell carbon powder is granulated using a
coal tar pitch binder and is carbonized. The granules are
carbonized at 600°C to 900°C and washed repeatedly with a
mineral acid such as hydrochloric acid. The granules are
then washed with water, dried, and impregnated with a pore
treatment such as creosote oil. The impregnated granules
are then heated at 600°C to 900°C and are cooled in an
inert gas to make the desired molecular sieve carbon. In
this fashion, the ash content of the molecular sieve
carbon can be reduced to 0.7 wt% or less and the pore size
can be adjusted as desired.
[0026]
The molecular sieve carbon so obtained can be used
in the PSA process to produce nitrogen from the air in an
industrially favorable manner. Though the underlying
mechanism is not fully understood, it is believed that
decalcifying the carbon material to reduce the ignition
residue to 0.7 wt% or less increases the pore volume, thus
increasing the volume of oxygen adsorption. The
decalcification also decreases the impurity during the
pore adjustment and thereby facilitates the formation of
pores suitable for the separation of nitrogen from the air.
The present invention will now be described in further

detail with reference to Examples, which are not intended
to limit the scope of the invention in any way.
[0027]
Production of molecular sieve carbon A:
4 0 parts by weight of coal tar and 8 parts by weight
of water were added to 100 parts by weight of fine crushed
coconut shell carbon and the mixture was thoroughly mixed
and kneaded. The mixture was pressed in a hydraulic press
and was extruded from a 0.8 mm nozzle to form cylindrical
granules. The resulting cylindrical granules were heated
at 600°C for 30 min in a fluid-type pyrolysis furnace and
were then cooled in nitrogen.
[0028]
The granules were thoroughly immersed in 0.6N
hydrochloric acid at 80°C while the solution was stirred.
Hydrochloric acid was then discarded. After washed three
times with hydrochloric acid, the granules were washed
with water and dried to make purified carbon, which in
turn was heated at 90 0°C in an external electric furnace
and was cooled in nitrogen. 3 parts by weight of a 14 0 to
260°C fraction of creosote oil were then added to the
purified carbon. This mixture was placed in a rotary kiln
in a weak stream of nitrogen gas and the temperature was
increased from room temperature to 400°C in 20 minutes to
thoroughly impregnate with creosote oil. Subsequently,

the temperature was further increased to 700°C in 20
minutes for heat treatment. The granules were then
allowed to cool to room temperature in nitrogen to give
molecular sieve carbon.
[0029]
Production of molecular sieve carbon B:
A molecular sieve carbon was obtained in the same
manner as molecular sieve carbon A, except that the
granules were not washed with hydrochloric acid.
[0030]
Production of molecular sieve carbon C:
A molecular sieve carbon was obtained in the same
manner as molecular sieve carbon A, except that the
granules were washed once with hydrochloric acid at room
temperature.
[0031]
Production of molecular sieve carbon D:
A molecular sieve carbon was obtained in the same
manner as molecular sieve carbon A, except that a 1.6 mm
nozzle was used.
[0032]
Production of molecular sieve carbon E:
A molecular sieve carbon was obtained in the same
manner as molecular sieve carbon A, except that a 0.4 mm
nozzle was used.

[0033]
Production of molecular sieve carbon F:
4 0 parts by weight of coal tar and 8 parts by weight
of water were added to 100 parts by weight of fine crushed
coconut shell carbon and the mixture was thoroughly mixed
and kneaded. The mixture was pressed in a hydraulic press
and was extruded from a 0.6 mm nozzle to formpellets.
With a high-speed mixer FS-G (Fukae Powtec) operated at
60°C, 400 rpm, the resulting cylindrical carbon granules
were formed into spheres with an average particle size of
1.0 mm. The spheric carbon granules were heated at 600°C
for 30 min in a fluid-type pyrolysis furnace and were
cooled in nitrogen. The rest of the procedure was
performed as described in the production of molecular
sieve carbon A to give molecular sieve carbon F. The
molecular sieve carbons A through F were analyzed for the
ash content as a measure of the ignition residue and the
equilibrium oxygen adsorption. The results are shown in
Table 1. In Table 1, "mL" denotes milliliter. The results
indicate that a molecular sieve carbon with a smaller
ignition residue tends to have a greater equilibrium
oxygen adsorption.


[0034]

[0035]
Examples 1 through 10 and Comparative Examples 1 through 4
Using the system shown in Fig. 1, a PSA process was
carried out for each of molecular sieve carbons A through
F with each adsorption column packed with 3.0L of a
corresponding molecular sieve carbon. Each process was
carried out using a corresponding pressure shown in Table
2. The results are shown in Table 2. In Table 2, "NL"
denotes normal litter and indicates the volume of nitrogen
gas under standard conditions



INDUSTRIAL APPLICABILITY
[0037]
According to the present invention, there is
provided an industrially viable PSA process that requires
small volumes of molecular sieve carbon and feed air. The
PSA process of the present invention can produce highly-
pure nitrogen with decreased volumes of molecular sieve
carbon and feed air. The process serves as a cost
effective PSA technique and is thus of industrial
importance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038]
Fig. 1 is a diagram showing an exemplary PSA system.
EXPLANATION OF REFERENCE SYMBOLS
[0039]
1 feed gas inlet line
2 compressor
3 cooler
4 adsorption column
5 adsorption column
6 product reservoir
7-14 valve

15 orifice
16 product nitrogen gas outlet line

17 discharge line

WE CLAIM:

1. A process for separating nitrogen, wherein a feed gas made up mainly of nitrogen is fed under pressure to one of at least two adsorption columns packed with molecular sieve carbon to conduct high pressure adsorption, the one of at least two adsorption columns having completed high pressure adsorption is subjected to low pressure desbrption, and the alternating cycle of the high pressure adsorption and the low pressure desorption are repeated in each adsorption column to separate nitrogen gas product, wherein
the molecular sieve carbon is obtained by adjusting pore size by heat treating charred coconut shell in an inert gas atmosphere and has 0.7 wt% or less ignition residue, and the following relationships (I) and (II) are satisfied:
(1) In C (2) In U where C indicates an oxygen level (ppm) in the nitrogen gas product; Q indicates a volume of nitrogen gas produced per minute per unit effective volume of a single adsorption column; P indicates an adsorption pressure (MPa); and U indicates a ratio of the volume of the feed air to the volume of the nitrogen gas produced.

2. The process for separating nitrogen as claimed in claim 1, wherein the molecular sieve carbon is spherical or cylindrical.
3. The process for separating nitrogen as claimed in claim 1 or 2, wherein the molecular sieve carbon has an outer diameter of 0.4 to 1.5 mm.
4. The process as claimed in claim 1, wherein the molecular sieve carbon has an equilibrium oxygen adsorption amount of 7.8 mL/g or more.




ABSTRACT


TITLE; METHOD OF SEPARATING NITROGEN GAS BY MOLECULAR SIEVE CARBON
This invention relates to a process for separating nitrogen, wherein a feed gas made up mainly of nitrogen is fed under pressure to one of at least two adsorption columns packed with molecular sieve carbon to conduct high pressure adsorption, the one of at least two adsorption columns having completed high pressure adsorption is subjected to low pressure desorption, and the alternating cycle of the high pressure adsorption and the low pressure desorption are repeated in each adsorption column to separate nitrogen gas product, wherein
the molecular sieve carbon is obtained by adjusting pore size by heat treating charred coconut shell in an inert gas atmosphere and has 0.7 wt% or less ignition residue, and the following relationships (I) and (II) are satisfied:
(1) In C (2) In U where C indicates an oxygen level (ppm) in the nitrogen gas product; Q indicates a volume of nitrogen gas produced per minute per unit effective volume of a single adsorption column; P indicates an adsorption pressure (MPa); and U indicates a ratio of the volume of the feed air to the volume of the nitrogen gas produced.

Documents:

0689-kolnp-2007 abstract.pdf

0689-kolnp-2007 claims.pdf

0689-kolnp-2007 correspondence others.pdf

0689-kolnp-2007 description(complete).pdf

0689-kolnp-2007 drawings.pdf

0689-kolnp-2007 form-1.pdf

0689-kolnp-2007 form-2.pdf

0689-kolnp-2007 form-3.pdf

0689-kolnp-2007 form-5.pdf

0689-kolnp-2007 international publication.pdf

0689-kolnp-2007 international search authority report.pdf

0689-kolnp-2007 others.pdf

0689-kolnp-2007 pct form.pdf

0689-kolnp-2007 priotrity document.pdf

689-KOLNP-2007-(02-09-2013)-ABSTRACT.pdf

689-KOLNP-2007-(02-09-2013)-CLAIMS.pdf

689-KOLNP-2007-(02-09-2013)-CORRESPONDENCE.pdf

689-KOLNP-2007-(02-09-2013)-FORM-1.pdf

689-KOLNP-2007-(02-09-2013)-FORM-2.pdf

689-KOLNP-2007-(06-02-2012)-CORRESPONDENCE.pdf

689-KOLNP-2007-ABSTRACT 1.1.pdf

689-KOLNP-2007-AMANDED CLAIMS.pdf

689-KOLNP-2007-CORRESPONDENCE.pdf

689-KOLNP-2007-DESCRIPTION (COMPLETE) 1.1.pdf

689-KOLNP-2007-DRAWINGS 1.1.pdf

689-KOLNP-2007-EXAMINATION REPORT REPLY RECIEVED.pdf

689-KOLNP-2007-EXAMINATION REPORT.pdf

689-KOLNP-2007-FORM 1-1.1.pdf

689-KOLNP-2007-FORM 18 1.1.pdf

689-kolnp-2007-form 18.pdf

689-KOLNP-2007-FORM 2-1.1.pdf

689-KOLNP-2007-FORM 26.pdf

689-KOLNP-2007-FORM 3 1.2.pdf

689-KOLNP-2007-FORM 3-1.1.pdf

689-KOLNP-2007-FORM 5 1.2.pdf

689-KOLNP-2007-FORM 5-1.1.pdf

689-KOLNP-2007-GRANTED-ABSTRACT.pdf

689-KOLNP-2007-GRANTED-CLAIMS.pdf

689-KOLNP-2007-GRANTED-DESCRIPTION (COMPLETE).pdf

689-KOLNP-2007-GRANTED-DRAWINGS.pdf

689-KOLNP-2007-GRANTED-FORM 1.pdf

689-KOLNP-2007-GRANTED-FORM 2.pdf

689-KOLNP-2007-GRANTED-SPECIFICATION.pdf

689-KOLNP-2007-OTHERS 1.1.pdf

689-KOLNP-2007-OTHERS.pdf

689-KOLNP-2007-PETITION UNDER RULE 137.pdf

689-KOLNP-2007-REPLY TO EXAMINATION REPORT.pdf

689-KOLNP-2007-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-00689-kolnp-2007.jpg


Patent Number 257302
Indian Patent Application Number 689/KOLNP/2007
PG Journal Number 39/2013
Publication Date 27-Sep-2013
Grant Date 23-Sep-2013
Date of Filing 26-Feb-2007
Name of Patentee KURARAY CHEMICAL CO. LTD.
Applicant Address 4342, TSURUMI, BIZEN-SHI, OKAYAMA 705-0025
Inventors:
# Inventor's Name Inventor's Address
1 YUKIHITO OTA C/O KURARAY CHEMICAL CO. LTD. 4342, TSURUMI, BIZEN-SHI, OKAYAMA 705-0025
PCT International Classification Number C01B 21/04
PCT International Application Number PCT/JP2005/014583
PCT International Filing date 2005-08-09
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2004-250485 2004-08-30 Japan