Title of Invention

PROCESS FOR RECOVERING CARBON DIOXIDE

Abstract In a process for obtaining CO2, desulfurized natural gas or gas which accompanies mineral oil is reformed autothermally with addition of oxygenous gas at a temperature of from 900 to 1200°C and a pressure of from 40 to 100 bar (a) by partial catalytic oxidation to give a crude synthesis gas, and then converted catalytically to. H2 and CO2 at a temperature of from 75 to 110°C and a pressure of from 50 to 75 bar (a) of CO, CO2 is scrubbed out of the synthesis gas obtained with methanol at a pressure of from 15 to 100 bar (a) and a temperature of from +10 to -80°C, and the absorbed CO2 is recovered by decompression. A further possible use of the process consists in converting the recovered CO2 to the supercritical state.
Full Text Process for Recovering Carbon Dioxide
This invention relates to a process for recovering CO2 from desulfurized natural gas or
petroleum gas liberated from C2+ components, which, preheated to a temperature of 45 to
75°C, is autothermally reformed in a first reaction stage by adding gas containing at least
[calculated dry] 75 vol-% O2 at a temperature of 900 to 1200°C and a pressure of 40 to
100 b'arabs by partial oxidation over a fixed bed of a cracking catalyst to Obtain "a raw
synthesis gas, containing as main components [calculated dry] 55 to 75 vol-% H2, 15 to 30
vol-% CO and 5 to 30 vol-% CO2 with a volume ratio of H2:CO of 1.6 to 4, in a second
reaction stage the CO contained in the raw synthesis gas having a temperature of 75 to
110°C and a pressure of 50 to 75 barabs is converted to H2 and CO2 over at least one
fixed-bed catalyst, from the synthesis gas containing at least [calculated dry] 55 vol-% H2
CO2 is washed out in at least one washing stage at a pressure of 15 to 100 barabs with
methanol having a temperature of +10 to -80°C, and absorbed CO2 is recovered by
expanding the cold methanol to almost atmospheric pressure.
From EP-B-1 337 466, there is known a process for catalytically generating NH3 from an
N2-H2 mixture. Natural gas together with a gas stream chiefly consisting of O2, preferably
at least 70 vol-%, is autothermally reformed at a temperature of 900 to 1200°C and a
pressure of 40 to 100 barabs in the presence of a cracking catalyst to obtain raw synthesis
gas, containing [calculated dry] 55 to 75 vol-% H2, 15 to 30 vol-% CO and 5 to 30 vol-%
CO2 at a volume ratio of H2:CO of 1.6 to 4. By catalytic conversion, the CO content of the
cooled raw synthesis gas withdrawn from the autothermal reformer is converted to H2, so
that the synthesis gas formed contains at least [calculated dry] 50 vol-% H2 and not more
than 8 vol-% CO. In a multistage gas wash, CO2, CO and CH4 are removed from the
synthesis gas, wherein in at least one of the stages liquid N2 is added for generating an
N2-H2 mixture for the catalytic production of ammonia in an ammonia synthesis. In the gas
wash, CO2 is removed with methanol having a temperature of -58°C and in conjunction
with the production of NH3 is used for generating urea. In the N2 wash, the synthesis gas
is cooled to a temperature of -185OC, so that first CH4 and then CO are condensed and
both components are recirculated to the autothermal reformer as fuel gas.

It is the object of the present invention to utilize the process described above for further
applications.
The solution of this object consists in that the CO2 recovered is transferred into the critical
condition, so that for solvent flooding the CO2 is injected into partially deoiied petroleum
deposits or can be stored in pore reservoirs, in cavern reservoirs, in depleted natural gas
deposits suitable as reservoir or in saline aquifers or can be used for oxo synthesis.
In accordance with the further aspect of the process, it is possible to wholly or partly
supply the H2 recovered as fuel to a gas turbine or another means for generating electrical
energy, for instance to a fuel cell, wherein in accordance with a further feature of the
invention the H2 can be diluted with up to 70 vol-% N2.
In accordance with a particular feature of the invention, part of the mechanical energy
generated by the gas turbine or another means for recovering electrical energy is utilized
for driving the compressor of the air separation plant and/or the compression plant for the
CO2; the remaining part is available as useful energy.
The invention will subsequently be explained in detail with reference to an embodiment in
conjunction with a basic flow diagram illustrated in the drawing.
Via conduit (1), natural gas is supplied to the pretreatment plant (4) with a pressure of 45
to 65 barabs and a temperature of 15 to 35°C, via conduit (2) steam and via conduit (3)
CH4 is supplied to the pretreatment plant (4), in which the natural gas is liberated from
sulfur compounds and C2+ components on a bed of Co-Mo catalyst with a downstream
bed of ZnO and preheated to a temperature of 55 to 75°C. The gas withdrawn from the
pretreatment plant (4) via conduit (5) is charged to an autothermal reformer (6) along with
high-oxygen gas supplied via conduit (7) with an 02 content of [calculated dry] 92 vol-%,
which is generated in an air separation plant (8) into which air is introduced via conduit
(9). In the autothermal reformer (6) a bed of commercially available NiO catalyst is
disposed, on which the natural gas is reformed by partial oxidation with 02 to obtain raw
synthesis gas containing CO, H2 and CO2 at a temperature of 900 to 1200°C and a
pressure of 40 to 100 barabs, preferably 40 to 80 barabs. The raw synthesis gas withdrawn
from the autothermal reformer (6) via conduit (10) contains [calculated dry] 55 to 75 vol-%
H2,15 to 30 vol-% CO and 5 to 30 vol-% CO2 at a volume ratio of H2:CO of 1.6 to 4. The
raw synthesis gas cooled intermediately in a non-illustrated heat exchanger to a

temperature of 25 to 45°C is passed into a two-stage converter (11) filled with a bed of
commercially available Fe-Cr catalyst, in which the CO still contained in the raw synthesis
gas stream is converted to CO2 and H2l wherein the volume ratio of H2:CO2 [calculated
dry] is 2.5 to 3. Upon traversing a non-illustrated heat exchanger, the synthesis gas
stream obtained by conversion and withrawn via conduit (12), which contains [calculated
dry] at least 65 vol-% H2 and not more than 8 vol-% CO, is introduced into a two-stage
physical gas washing plant (13). In the first stage (14) of the gas washing plant (13), CO2
is absorbed by means of methanol having a temperature of -20 to -70°C at a pressure of
40 to 80 baraqs. In the second stage (15) of the gas washing plant (13), the impurities CO,
CH4 and Ar left in the synthesis gas stream upon removal of CO2 are absorbed by means
of liquid nitrogen recovered in" the air separation plant (8) and charged to the second stage
(15) via conduit (16). For- removing absorbed CO2 from the methanol and the absorbed
CO, CH4 and Ar from' the N2, the methanol and the N2 are expanded to almost
atmospheric pressure. Via conduit (17), the CO2 recovered is supplied to a plant (18) in
which the CO2 is brought into the supercritical condition by increasing pressure and
temperature, and via conduit (19) it is injected into partly deoiled petroleum deposits for
solvent flooding. The gas stream containing CO, CH4 and Ar is recirculated to the
autothermal reformer (6) as fuel gas via conduit (20). Via conduit (21), the H2 obtained
during the absorption of the CO2 in the first stage (14) of the gas washing plant (13) flows
as fuel into the combustion chamber of a gas turbine (22).
The data obtained with a concrete embodiment of the process of the invention for
substance amounts, temperatures, pressures and composition of the gas streams are
listed in the following table with reference to the basic flow diagram illustrated in the
drawing.


For the gas wash (13), the known Rectisol® process is used, in which in the first stage
(14) CO2 is absorbed with methanol having a temperature of -58°C. In the second stage
(15) of the gas wash (13), the temperature of the synthesis gas initially is decreased to a
value of -185°C, so that the CR, is condensed, separated and recirculated into the
autothermal reformer (3) as fuel gas together with the likewise separated CO and Ar.
The advantages achievable with the invention in particular consist in that
emissions of CO2 are prevented, in particular for ecological reasons,
the process for recovering supercritical CO2 can be used directly in situ for solvent
flooding largely deoiled petroleum deposits in petroleum prospects,
the petroleum gas obtained in the recovery of petroleum can be processed directly
in situ in many petroleum prospects, and the gas components generated can be
utilized within the process.


Claims:
1. A process for recovering CO2 from desulfurized natural gas or petroleum gas
liberated from C2+ components, which, preheated to a temperature of 45 to 75°C, is
autothermally reformed in a first reaction stage by adding gas containing at least
[calculated dry] 75 vol-% 02 at a temperature of 900 to 1200°C and a pressure of 40
to 100 barabs by partial oxidation over a fixed bed of a cracking catalyst to obtain a
raw synthesis gas, containing as main components [calculated dry] 55 to 75 vol-%
H2, 15 to 30 vol-% CO and 5 to 30 vol-% CO2 [calculated dry] with a volume ratio of
H2:CO of 1.6 to 4, in a second reaction stage the CO contained in the raw synthesis
gas having a temperature of 75 to 110°C and a pressure of 75 to 50 barabs is
converted to H2 and CO2 over at least one fixed-bed catalyst, from the synthesis gas
containing at least 55 vol-% H2 [calculated dry] CO2 is washed out in at least one
washing stage at a pressure of 15 to 100 barabs with methanol having a temperature
of +10 to -80°C, and absorbed CO2 is recovered by expanding the cold methanol to
almost atmospherio pressure, characterized in that the CO2 recovered is
transferred into the supercritical condition.
2. Use of the' CO2 recovered by the process according to claim 1 for solvent flooding
partly deoiled petroleum deposits or for storage in pore reservoirs, cavern
reservoirs, depleted natural gas deposits and saline aquifers or for oxo synthesis.
3. The process according to claim 1, characterized in that the H2 recovered is
supplied as fuel to a gas turbine and/or another means for generating electrical
energy, for instance to a fuel cell.
4. The process according to claim 3, characterized in that the H2 recovered is diluted
with 70 vol-% N2.
5. The process according to any of claims 3 and 4, characterized in that part of the
mechanical energy generated by the gas turbine is utilized for driving the
compressor of the air separation plant.

The process according to any of claims 3 to 4, characterized in that part of the
mechanical energy generated by the gas turbine is utilized for driving the
compressor for the CO2.

In a process for obtaining CO2, desulfurized natural gas or gas which accompanies mineral oil is reformed autothermally with addition of oxygenous gas at a temperature of from 900 to 1200°C and a pressure of from 40 to 100 bar (a) by partial catalytic oxidation to give a crude synthesis gas, and then converted catalytically to. H2 and CO2 at a temperature of from 75
to 110°C and a pressure of from 50 to 75 bar (a) of CO, CO2 is scrubbed out of the synthesis gas obtained with methanol at a pressure of from 15 to 100 bar (a) and a temperature of from +10 to -80°C, and the absorbed CO2 is recovered by decompression. A further possible use of the process consists in converting the recovered CO2
to the supercritical state.

Documents:

1720-KOLNP-2009-(12-04-2013)-CLAIMS.pdf

1720-KOLNP-2009-(12-04-2013)-CORRESPONDENCE.pdf

1720-KOLNP-2009-(12-04-2013)-OTHERS.pdf

1720-KOLNP-2009-(22-08-2013)-PETITION UNDER RULE 137.pdf

1720-KOLNP-2009-(30-10-2012-RI)-ANNEXURE TO FORM 3.pdf

1720-KOLNP-2009-(30-10-2012-RI)-CORRESPONDENCE.pdf

1720-KOLNP-2009-(30-10-2012-RI)-OTHERS.pdf

1720-kolnp-2009-abstract.pdf

1720-kolnp-2009-claims.pdf

1720-KOLNP-2009-CORRESPONDENCE-1.1.pdf

1720-KOLNP-2009-CORRESPONDENCE-1.2.pdf

1720-kolnp-2009-correspondence.pdf

1720-kolnp-2009-description (complete).pdf

1720-kolnp-2009-drawings.pdf

1720-kolnp-2009-form 1.pdf

1720-kolnp-2009-form 18.pdf

1720-kolnp-2009-form 2.pdf

1720-kolnp-2009-form 3.pdf

1720-kolnp-2009-form 5.pdf

1720-kolnp-2009-international publication.pdf

1720-kolnp-2009-international search report.pdf

1720-KOLNP-2009-OTHERS.pdf

1720-kolnp-2009-pct request form.pdf

1720-KOLNP-2009-PRIORITY DOCUMENT.pdf

1720-kolnp-2009-specification.pdf

1720-KOLNP-2009-TRANSLATED COPY OF PRIORITY DOCUMENT.pdf

abstract-1720-kolnp-2009.jpg


Patent Number 257500
Indian Patent Application Number 1720/KOLNP/2009
PG Journal Number 41/2013
Publication Date 11-Oct-2013
Grant Date 09-Oct-2013
Date of Filing 08-May-2009
Name of Patentee LURGI GMBH
Applicant Address LURGIALLE 5 60295 FRANKFURT AM MAIN
Inventors:
# Inventor's Name Inventor's Address
1 KOSS, ULRICH MARTINSTRASSE 83, 64285 DARMSTADT
PCT International Classification Number B01D 53/00,C01B 3/02
PCT International Application Number PCT/EP2007/009442
PCT International Filing date 2007-10-31
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 10 2006 054 472.2 2006-11-18 Germany