U.S. patent application number 14/236817 was filed with the patent office on 2014-08-07 for method and device for dehydrating a co2 containing gas.
This patent application is currently assigned to VICTORIA CAPITAL INVESTMENTS GROUP LTD.. The applicant listed for this patent is Leonard Makarovich Dmitriev, Salavat Zainetdinovich Imaev. Invention is credited to Leonard Makarovich Dmitriev, Salavat Zainetdinovich Imaev.
Application Number | 20140216104 14/236817 |
Document ID | / |
Family ID | 47557019 |
Filed Date | 2014-08-07 |
United States Patent
Application |
20140216104 |
Kind Code |
A1 |
Imaev; Salavat Zainetdinovich ;
et al. |
August 7, 2014 |
METHOD AND DEVICE FOR DEHYDRATING A CO2 CONTAINING GAS
Abstract
Proposed is a method for dehydrating a CO.sub.2 containing gas
(1) by cooling the gas (1) and separating the condensed water from
the gas (1), wherein the gas is contacted with liquid CO.sub.2 to
condense water contained in the gas (1) and the condensate is
separated from the remaining gas. Further, a device for dehydrating
a CO.sub.2 containing gas is proposed, comprising a gas feeding
system for feeding the gas which has to be dehydrated, wherein the
device comprises a CO.sub.2 feeding system for feeding liquid
CO.sub.2, a contacting device (C) for contacting the gas and the
liquid CO2 for cooling the gas (1) to condense the water contained
in the gas (1), and which comprises a first separator (4) for
separating the condensate from the remaining gas.
Inventors: |
Imaev; Salavat Zainetdinovich;
(Ramenskoye, RU) ; Dmitriev; Leonard Makarovich;
(Zhukovsky, RU) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Imaev; Salavat Zainetdinovich
Dmitriev; Leonard Makarovich |
Ramenskoye
Zhukovsky |
|
RU
RU |
|
|
Assignee: |
VICTORIA CAPITAL INVESTMENTS GROUP
LTD.
Limassol
CY
|
Family ID: |
47557019 |
Appl. No.: |
14/236817 |
Filed: |
October 10, 2012 |
PCT Filed: |
October 10, 2012 |
PCT NO: |
PCT/EP2012/070029 |
371 Date: |
February 3, 2014 |
Current U.S.
Class: |
62/617 |
Current CPC
Class: |
F25J 3/08 20130101; B01D
53/28 20130101; B01D 53/263 20130101; B01D 2256/22 20130101 |
Class at
Publication: |
62/617 |
International
Class: |
F25J 3/08 20060101
F25J003/08 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 18, 2011 |
DE |
10 2011 084 733.2 |
Claims
1. A method for dehydrating a CO.sub.2 containing gas by cooling
the gas (1) and separating the condensed water from the gas (1),
wherein the gas (1) is contacted with liquid CO.sub.2 for cooling
the gas (1) to condense water contained in the gas (1) and the
condensate is separated from the remaining gas, and wherein the
remaining gas which comprises gaseous CO.sub.2 is expanded to
condense water contained in the gas, and the thus obtained liquid
phase comprising liquid CO.sub.2 water (10) and, optionally,
hydrates is separated from the dehydrated gas.
2. (canceled)
3. The method according to claim 1, characterized in that the
obtained liquid phase (10) is at least partially used for
contacting with the gas to be dehydrated.
4. The method according to claim 1, wherein the liquid CO.sub.2 to
be mixed with the gas has a temperature within a range of
-60.degree. C. to 20.degree. C.
5. The method according to claim 1, wherein the gas to be mixed
with the liquid CO.sub.2 has a temperature within a range of
-40.degree. C. to 50.degree. C.
6. The method according to claim 1, wherein the temperature of the
gas is lowered by expansion below 0.degree. C.
7. The method according to claim 1, wherein the pressure of the gas
is lowered by expansion below 7000 kPa.
8. The method according to claim 1, wherein the obtained liquid
phase comprising liquid CO.sub.2, water (10) and, optionally,
hydrates has a pressure of 100 kPa to 7000 kPa and a temperature of
-63.degree. C. to 20.degree. C.
9. A device for dehydrating a CO.sub.2 containing gas, comprising a
gas feeding system for feeding the gas (1) to be dehydrated, a
CO.sub.2 feeding system for feeding liquid CO.sub.2, a contacting
device (C) for contacting the gas (1) and the liquid CO.sub.2 for
cooling the gas (1) to condense water contained in the gas (1), a
first separator (4) for separating the condensate from the
remaining gas, and an expansion device for cooling the remaining
gas which comprises gaseous CO.sub.2 and for obtaining a liquid
phase comprising liquid CO.sub.2, water (10) and, optionally,
hydrates.
10. (canceled)
11. Device for dehydrating a CO.sub.2 containing gas according to
claim 9, wherein the expansion device is a turbine (13).
12. Device for dehydrating a CO.sub.2 containing gas according to
claim 9, wherein the device comprises a second separator (9) for
separating the liquid phase (10) from the dehydrated gas, wherein
the second separator (9) is fluidicly connected to the contacting
device (C).
13. Device for dehydrating a CO.sub.2 containing gas according to
claim 11, wherein the device comprises a compressor (14) for
application of pressure on the dehydrated gas (12), wherein the
turbine (13) is mechanically connected to the compressor (14) in
such a manner that the torque generated by the turbine (13) is
usable or is used for driving the compressor (14).
14. A method comprising using a device for dehydrating a CO.sub.2
containing gas according to claim 9 for dehydrating a CO.sub.2
containing gas (1), wherein the CO.sub.2 containing gas is natural
gas.
Description
[0001] The present invention relates to a method for dehydrating a
CO.sub.2 containing gas by cooling the gas and separating the
condensed water from the gas, wherein the gas is contacted with
liquid CO.sub.2 to condense water contained in the gas and the
condensate is separated from the remaining gas. Further, a device
for dehydrating a CO.sub.2 containing gas is proposed comprising a
gas feeding system for feeding the gas which has to be dehydrated,
wherein the device comprises a CO.sub.2 feeding system for feeding
liquid CO.sub.2, a device for contacting the gas and the liquid
CO.sub.2 for cooling the gas to condense the water contained in the
gas and comprising a first separator for separating the condensate
from the remaining gas.
[0002] According to the invention the CO.sub.2 containing gases to
be dehydrated comprise natural gas, as well as gases containing
other than hydrocarbonic gases, such as methane, ethane, propane,
butane, pentane etc, and also hydrogen sulfide, nitrogen, oxygen
etc.
[0003] It is known to dehydrate carbonic acid gas by consistently
compressing the gas in two compressors (see patent CA 325811,
1932). After that each compressor gas is cooled in air chillers and
directed to a trap in which condensed moisture is removed from the
gas.
[0004] The gas from the trap is directed to an adsorber where in a
process of adsorption of water vapour definitive carbonic gas
dehydration occurs.
[0005] Drawbacks of the way discussed above are huge dimensions of
the installations realizing this way caused by presence and costs
of adsorber, and also the necessity of an energy supply for the
regeneration of the absorber.
[0006] A further way of dehydrating gases is described in DE 20 65
941 C2, where the gas is cooled in a heat exchanger using a cold
gas and injection of ammonia.
[0007] DE 2014776 teaches the use of CO.sub.2 as a cooling element
in a heat exchanger for cooling natural gas.
[0008] A further known method is the dehydration of high pressure
gas enriched with carbonic acid gas (compare JP 63074908, 1988), in
which the gas containing CO.sub.2 is cooled by means of an air
chiller, wherein the cooled gas extends in a throttle valve. The
water formed after expansion is separated from the gas in a
separator. The obtained gas is compressed in a compressor, cooled
in an air chiller and supplied to a final gas consumer.
[0009] A serious drawback of the described way is the impossibility
of achieving deep-cut gas dehydration. This is due to the
impossibility of obtaining low temperatures of the gas in the
course of its expansion caused by the possible formation of
hydrates at low temperatures.
[0010] It is therefore the object of the present invention to
provide a method and a corresponding device for an effective and
high degree dehydration of CO.sub.2 containing gases.
[0011] The problem of the present invention is solved by providing
a method for dehydrating a CO.sub.2 containing gas wherein the gas
is mixed with liquid CO.sub.2 for cooling the gas to condense water
contained in the gas and the condensate is separated from the
remaining gas. That is, the gas is directly contacted with liquid
CO.sub.2 in order to condense water contained in the gas.
[0012] The separation of condensed water, of possible hydrates and
of water dissolved in liquid CO.sub.2 may be carried out in a
separator.
[0013] By cooling with liquid CO.sub.2 very low temperatures are
achievable and the condensation process may be carried out in a
very efficient way. A further advantage of the present method is
that condensation of the water vapour to water can be realized with
very low costs.
[0014] In a preferred embodiment of the present invention the gas
which is obtained after contacting with liquid CO.sub.2 and which
comprises gaseous CO.sub.2 is expanded to condense remaining water
in this gas and the obtained liquid phase comprising liquid
CO.sub.2, water and, optionally, hydrates is separated from the
dehydrated gas. The dehydrated gas will be derived.
[0015] Due to the strong cooling of the gas phase by mixing with
fluid CO.sub.2, the expansion can be realized with a very small
energy input. Further, hydrate crystals optionally formed in the
course of expansion are dissolved in liquid CO.sub.2 which is also
formed at expansion. This way the efficiency of the gas dehydration
process is increased.
[0016] In an especially preferred embodiment of the invention the
obtained liquid phase comprising liquid CO.sub.2, water and,
optionally, hydrates is partially or completely used for mixing
with a gas to be dehydrated. The liquid phase may be separated in a
separator.
[0017] That means, the liquid CO.sub.2 produced as a by-product
during a cooling process is used for cooling the gas in another
cooling process of the present invention in order to dehydrate the
gas. Additionally, expansion of the gas to be dehydrated below
temperature of hydrate formation allows separation of the formed
hydrates because they are dissolved in the liquid CO.sub.2. also
generated in the expansion process.
[0018] Preferably, the liquid CO.sub.2 which is mixed with the gas
to be dehydrated has a temperature within a range from -60.degree.
C. to 20.degree. C. The most preferred range is from -40.degree. C.
to -20.degree. C.
[0019] The gas which is mixed with the liquid CO.sub.2 has
preferably a temperature within a range from -40.degree. C. to
50.degree. C. The most preferred range is from 30.degree. C. to
50.degree. C.
[0020] In an especially preferred embodiment, the gas has a
temperature of about 40.degree. C. and the liquid CO2 has a
temperature of about -27.degree. C. The pressure of the gas is
preferably within a range from 4000 to 6000 kPa, more preferred at
about 5000 kPa.
[0021] The temperature of the gas may preferably be lowered by
expansion below 0.degree. C. and most preferred to at most
-20.degree. C. The pressure of the gas is preferably lowered by
expansion below 7000 kPa and most preferred to at most 2000
kPa.
[0022] In an especially preferred embodiment before the expansion
the gas phase has a temperature of about 15.degree. C. and a
pressure of about 5000 kPa. After cooling by expansion the gas
phase has a temperature of at most -20.degree. C. and a pressure of
at most 2000 kPa.
[0023] The obtained liquid phase comprising liquid CO.sub.2 and
water may have a pressure within a range from 100 kPa to 7000 kPA
and a temperature within a range from -63.degree. C. to 20.degree.
C. In the most preferred embodiment the obtained liquid phase
comprising liquid CO.sub.2 and water may have a pressure within a
range from 1200 kPa to 1600 kPa and a temperature within a range
from -40.degree. C. to -20.degree. C.
[0024] Preferably the pressure of the liquid phase comprising
liquid CO.sub.2 and water is 1400 kPa and the temperature is
-30.degree. C.
[0025] The liquid phase comprising liquid CO.sub.2 and water is
preferably pumped up to a pressure of about 5000 kPa, wherein
temperature increases up to about -27.degree. C.
[0026] The liquid phase comprising liquid CO.sub.2 and water and
having the high pressure is mixed with the next load of gas, where
applicable in a continuous process.
[0027] According to the present invention there is also provided a
device for dehydrating a CO.sub.2 containing gas comprising a gas
feeding system for feeding gas which has to be dehydrated, wherein
the device comprises a CO.sub.2 feeding system for feeding liquid
CO.sub.2, a contacting device for contacting the gas and the liquid
CO.sub.2 for cooling the gas so that water comprised in the gas is
partially or completely condensed, and comprises a first separator
for separating the condensate from the remaining gas.
[0028] The contacting device may be a mixing device for mixing the
gas and the liquid CO.sub.2. In some cases the contacting device
may be a vessel or a tower.
[0029] Preferably, the device comprises an expansion device for
cooling the remaining gas which comprises gaseous CO.sub.2 and for
obtaining a liquid phase containing liquid CO.sub.2 and water and,
optionally hydrates, as well as for obtaining dehydrated gas.
[0030] For separating the liquid phase containing liquid CO.sub.2
and water from the dehydrated gas, the device comprises a second
separator, wherein the second separator is fluidically connected to
the contacting device.
[0031] The fluidic connection is arranged in order to feed the
liquid phase containing liquid CO.sub.2 and water into the
contacting device for cooling the gas.
[0032] Preferably, the expansion device is a turbine or a so called
turbo expander.
[0033] In that case, the device may comprise a a compressor for
application of pressure on the gas, wherein the turbine is
mechanically connected to the compressor in such a manner that the
torque generated by the turbine is usable or is used for driving
the compressor.
[0034] As an alternative, torque of the turbine is used for driving
a generator, wherein electrical energy generated by the generator
is used for driving the compressor and/or other aggregates.
[0035] The device according to the invention can be a part of a
system for extracting CO.sub.2 from gases, in particular from
natural gases.
[0036] A further subject-matter of the present invention is the use
of the device for dehydrating a CO.sub.2 containing gas according
to the invention for dehydrating a CO.sub.2 containing gas, in
particular for dehydrating natural gas.
[0037] That is, subject-matter of the present invention is the use
of the device according to the invention for performing the method
according to the invention.
[0038] The present invention provides a method for the dehydration
of gas containing CO.sub.2, based on reception of a bi-phased mix
at its expansion and extraction from a mixture of liquid phase in a
separator. According to the invention, preferably crude gas is
cooled and contacted or mixed with liquid CO.sub.2 with water
dissolved in it. The received mixture is divided into a gas phase
and a liquid phase containing water. The gas phase is expanded,
obtaining the liquid containing liquid CO.sub.2 and water, wherein
liquid is partially or completely routed to mixture with the crude
gas, thus expansion is possible at a temperature below the
temperature of hydrate formation.
[0039] In the course of expansion, gas can be passed through a
throttle valve or through a turbine, namely in a so called
turbo-expander.
[0040] In case of gas expansion in a turbo expander it is possible
to compress the dry or crude gas in a compressor by means of the
torque generated by the turbo expander. That is, the shaft of the
turbo expander may be mechanically connected to the compressor.
[0041] The gas can also be expanded in a swirling stream in the
channel of a cyclonic separator or in the channel of a vortex
tube.
[0042] Expansion process can occur, at least, in two stages, and in
one of the stages expansion occurs in a cyclonic separator and/or
in the throttle valve.
[0043] The bi-phase mixture received after expansion can be
separated to the dry gas and to a bi-phase stream from which it is
possible to extract liquid in an additional separator. The liquid
phase of the additional separator is compressed, cooled and mixed
with crude gas.
[0044] In the following the present invention is explained on the
basis of examples shown in the enclosed drawings.
[0045] FIG. 1 shows in a scheme a device according to the invention
in a first embodiment.
[0046] FIG. 2 shows in a scheme a device according to the invention
in a second embodiment.
[0047] FIG. 3 shows in a scheme a device according to the invention
in a third embodiment.
[0048] FIG. 4 shows in a scheme a device according to the invention
in a fourth embodiment.
[0049] FIG. 5 shows in a scheme a device according to the invention
in a fifth embodiment.
[0050] FIG. 6 shows in a scheme a device according to the invention
in a sixth embodiment.
[0051] FIG. 7 shows in a scheme a device according to the invention
in a seventh embodiment.
[0052] FIG. 8 shows in a scheme a device according to the invention
in a eighth embodiment.
[0053] In FIG. 1 a principal diagram shows the installation of a
device for realizing a proposed method of low-temperature
dehydration of the gas containing CO2. That is, FIG. 1 shows an
installation scheme realizing the method according to the
invention, wherein gas expansion is carried out in a Joule-Thompson
valve.
[0054] Crude gas 1 containing CO.sub.2 is cooled by contacting or
mixing it with a stream 2 of liquid CO.sub.2 with water dissolved
in it.
[0055] That is, the crude gas 1 directly contacts the stream 2
containing liquid CO.sub.2 for cooling the gas in order to condense
water contained in the crude gas 1.
[0056] The obtained mixture 3 is divided in a separator 4 into a
gas phase 5 and a liquid phase 6 containing water. Stream 6 may
contain water as in a free form, as in the dissolved form, as well
as in the form of hydrates. That is, stream 6 may include water as
a liquid, liquid CO.sub.2 and/or other condensed components
contained in the crude gas 1, gas phase 5 is expanded in a throttle
valve 7, obtaining a bi-phase mixture 8 from which in a separator 9
liquid 10 containing liquid CO.sub.2 and water is separated. By
means of a pump 11 this liquid or a part of it is conducted to be
mixed with crude gas 1. The dried gas 12 is subjected to further
processing if necessary, so that the dehydrated gas may be
straightly supplied to gas consumer.
[0057] Gas expansion in the throttle valve 7 occurs at a
temperature below the temperature of hydrates formation.
[0058] In order to define the temperature of hydrates formation in
a stream after a throttle valve or other expansion devices, widely
known software programs, such as HYSYS etc. can be used. The
condition of achievement of the stream temperature lower than the
temperature of hydrates formation is provided by choice of
sufficient degree of gas expansion.
[0059] In the described device, gas dehydration is carried out by
means of gas cooling during its expansion in the throttle valve 7.
Liquid containing liquid CO.sub.2 and water formed in that process
is directed to crude gas 1. Water is separated from the liquid
phase formed after mixture of crude gas 1 and liquid 2 containing
liquid CO.sub.2 and water. It is worth noticing that by means of
contacting or mixing of crude gas 1 with a liquid 2 containing
liquid CO.sub.2, gas is strongly cooled by means of evaporation of
liquid CO.sub.2.
[0060] Expansion of gas to temperature below the temperature of
hydrates formation allows to increase the efficiency of the gas
dehydration process according to the invention. If hydrate crystals
are formed in the course of expansion, these hydrate crystals will
be dissolved in liquid CO.sub.2 which is also formed during
expansion.
[0061] In certain cases, when in a stream there is free water and
the temperature of a stream 3 is below the temperature of hydrates
formation, hydrates of water are separated in the separator 4, and
then destroyed by their heating, or by injection of hydrates
formation inhibitors (methanol, glycol, etc).
[0062] In order to increase gas dehydration, it is possible to
carry out a stronger pre-cooling of gas by means of turbo expander
as shown in FIG. 2, which is a preferred embodiment of the present
invention. That is, in FIG. 2 gas expansion is carried out by means
of a turbo expander 13. The turbo expander 13 in that embodiment is
installed instead of the throttle valve 7 shown in FIG. 1, wherein
a shaft of the compressor 11 may be connected to the shaft of the
turbo expander 13.
[0063] In FIG. 2 the compressor 14 is installed in the drained gas.
However, the compressor 11 could be located either in the drained
gas stream, or in the crude gas stream.
[0064] Parameters of the streams in the system shown in FIG. 2 are
listed in table 1 below.
[0065] In the case under consideration, crude gas 1 consists
basically of carbonic acid gas. Preferably, inlet pressure of crude
gas is 6000 kPa and the temperature of the crude gas is 40.degree.
C. Target pressure of the dry gas is 3000 kPa.
[0066] As shown in FIG. 3, the compressor 14 is installed in the
crude gas stream 1. In order to decrease the temperature of crude
gas after the compressor 14, it is expedient to install an
additional air cooling device 18. Preferably, also in that
embodiment a shaft of the compressor 11 is connected to the shaft
of the turbo expander.
[0067] The device for dehydration, using the proposed method, can
be part of a complex unit for CO.sub.2 extraction from gas.
[0068] In certain cases in order to reduce costs and operational
expenses, a cyclonic separator or a vortex tube can be installed
instead of the turbo expander. In these cases, a lower pressure is
achievable in the course of gas expansion in the channel of a
cyclonic separator or a vortex tube and it is possible to reach
lower temperatures of gas, and thus to increase efficiency of gas
dehydration process.
[0069] A further possible example of a device and a method
according to the invention having a cyclonic separator or vortex
tube for gas expansion is shown in FIG. 4. Position 20 designates a
cyclonic separator or a vortex tube.
[0070] In certain cases it is not possible to qualitatively
separate the gas stream from a liquid in a vortex tube or a
cyclonic separator. Then, the bi-phase stream 21 routing from a
cyclonic separator or a vortex tube is directed to a separator 9
where liquid 10 is separated and directed to mixing with crude gas
as shown in FIG. 5. That is, in that embodiment a two-level
expansion of gas is carried out.
[0071] For a possibility to control parameters of the dehydration
process in a wide range, expansion can be carried out at least in
two stages. In one of the stages expansion is conducted in a
cyclonic separator and/or in a throttle valve.
[0072] One of the variants for the realization of the invention
with a two-stage expansion of gas is shown in FIG. 6. Here the
bi-phase stream flowing from a cyclonic separator or a vortex tube
is directed to an additional separator where separation of the
liquid, directed to mixture with crude gas, takes place. In this
variant first gas expands in turbo expander 13, and then in the
channel of a cyclonic separator or a vortex tube 20.
[0073] In FIG. 7 a method and a device are shown in which the
bi-phase mix obtained after expansion is separated from the dry
gas. The liquid is extracted in an additional separator from a
bi-phase stream. Gas from an additional separator is compressed,
cooled and mixed up with crude gas. That is, the bi-phase mixture
obtained after expansion is separated from the drained gas and a
bi-phase stream from which liquid in an additional separator is
extracted. In FIG. 7 an example for realization of such a case is
shown.
[0074] After gas expansion in turbo expander 13, gas additionally
expands in the channel of a vortex tube (or a cyclonic separator)
20. Before the gas is conducted to the vortex tube (for example to
a cyclonic separator), it is possible to separate condensate 29
from gas. The bi-phase stream from the vortex tube is routed to an
additional separator 9, the liquid from this additional separator
is routed to the crude gas, and the gas is further compressed in
the compressor 14, cooled in the air cooling device 18 and mixed
with crude gas.
[0075] For a stronger cooling of gas, and accordingly lowering the
dew-point of the water of the drained gas, crude gas, and/or a mix
formed after mixture of crude gas with a liquid containing water in
the dissolved form may be cooled.
[0076] In FIG. 8 an example for realization of such a cooling is
shown. Here crude gas formed after mixture of crude gas with a
liquid containing water in the dissolved form is cooled. That is,
crude gas in the given variant is cooled consistently in the air
cooling device 18 and in the recuperative heat exchanger 24.
[0077] In all alternatives of the method according to the invention
there is the possibility of adding liquid containing free water to
crude gas before its expansion is realized, wherein this liquid can
be additionally cooled.
[0078] Following table 1 exhibits the operability and the results
achieved with the method of the invention, especially the results
which are achievable with a device according to FIG. 2.
TABLE-US-00001 TABLE 1 1 2 3 5 6 8 10 12 15 temperatur, .degree. C.
40.00 -27.86 15.46 15.46 15.46 -30.23 -30.23 -30.23 31.52 pressure
(kPa) 5066.25 5066.25 5066.25 5066.25 5066.25 1400.00 1400.00
1400.00 2985.85 mass flow 300410 52937 353347 337894 15453 337894
52930 284965 284965 (kg/h) water dissolved in 410 159 325 160 165
160 159 1 1 liquid CO.sub.2 (kg/h) "free" water 0 0 244 0 244 0 0 0
0 (kg/h) content of CO.sub.2, in 0.9768 0.9921 0.9791 0.9811 0.9350
0.9811 0.9921 0.9791 0.9791 mol content of N.sub.2, in 0.0199
0.0006 0.0170 0.0177 0.0028 0.0177 0.0006 0.0209 0.0209 mol content
H.sub.2O, in mol 0.0033 0.0073 0.0039 0.0011 0.0622 0.0011 0.0073
0.0000* 0.0000* *value 0.0000 means that the water content is less
than 0.0001
LIST OF REFERENCE SIGNS
[0079] contacting device c [0080] crude gas 1 [0081] stream of
liquid CO.sub.2 with water dissolved in it 2 [0082] mixture of
crude gas and liquid CO.sub.2 3 [0083] first separator 4 [0084] gas
phase 5 [0085] liquid phase containing water 6 [0086] throttle
valve 7 [0087] bi-phase mixture 8 [0088] second separator 9 [0089]
liquid phase containing liquid CO.sub.2 and water 10 [0090] pump 11
[0091] dried gas 12 [0092] turbo expander, turbine 13 [0093]
compressor 14 [0094] dried gas 15 [0095] gas phase 16 [0096]
additional separator 17 [0097] air cooling device 18 [0098] cooled
gas 19 [0099] cyclonic separator or a vortex tube 20 [0100]
bi-phase stream 21 [0101] purified gas 22 [0102] mixture of
purified gas 22 and gas phase 16 23 [0103] heat exchanger 24 [0104]
cooled gas 25 [0105] gas after compression 26 [0106] dried gas 27
[0107] gas phase 28 [0108] condensate 29 [0109] condensate after
Joule-Thompson valve 30 [0110] Joule-Thompson valve 31
* * * * *