U.S. patent application number 12/348540 was filed with the patent office on 2009-04-30 for integrated process and gas treatment process.
This patent application is currently assigned to L'AIR LIQUIDE SOCIETE ANONYME POUR L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGE. Invention is credited to Alain Guillard, Patrick Le Bot, Bernard Saulnier.
Application Number | 20090107176 12/348540 |
Document ID | / |
Family ID | 34838207 |
Filed Date | 2009-04-30 |
United States Patent
Application |
20090107176 |
Kind Code |
A1 |
Guillard; Alain ; et
al. |
April 30, 2009 |
Integrated Process and Gas Treatment Process
Abstract
Integrated air separation units with a petrochemical process.
This invention provides an integrated process and gas treatment
process wherein at least one first pressurized gas derived from a
first process at a first site is expanded. Using the work generated
by the expansion of at least one pressurized gas, a first gas
compressor at the first site is driven, operates, and removes
compressed gas from the first gas compressor. At least part of the
compressed gas from the first gas compressor is sent to a gas
treatment unit located at a remote second site. At least part of
the compressed gas sent from the first site to the second site is
treated in the gas treatment unit. At least one fluid from the gas
treatment unit is removed and at least part of the fluid removed
from the gas treatment unit is sent to the first site.
Inventors: |
Guillard; Alain; (Paris,
FR) ; Le Bot; Patrick; (Vincennes, FR) ;
Saulnier; Bernard; (La Garenne Colmbes, FR) |
Correspondence
Address: |
AIR LIQUIDE;Intellectual Property
2700 POST OAK BOULEVARD, SUITE 1800
HOUSTON
TX
77056
US
|
Assignee: |
L'AIR LIQUIDE SOCIETE ANONYME POUR
L'ETUDE ET L'EXPLOITATION DES PROCEDES GEORGE
PARIS
FR
|
Family ID: |
34838207 |
Appl. No.: |
12/348540 |
Filed: |
January 5, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11159954 |
Jun 23, 2005 |
7490484 |
|
|
12348540 |
|
|
|
|
Current U.S.
Class: |
62/643 |
Current CPC
Class: |
F25J 3/04121 20130101;
F25J 3/04036 20130101; F25J 2240/02 20130101; F25J 3/04539
20130101; F25J 3/04109 20130101; F25J 2290/12 20130101; Y02P 20/125
20151101; Y02P 20/10 20151101; F25J 3/04957 20130101; F25J 3/04145
20130101; F25J 3/04018 20130101; F25J 3/04115 20130101 |
Class at
Publication: |
62/643 |
International
Class: |
F25J 3/04 20060101
F25J003/04 |
Claims
1. A method which may be used as an integrated gas treatment
process, said method comprising: a) expanding at least one first
pressurized gas, wherein said first pressurized gas is derived from
at least one first process performed at a first site; b) driving at
least a first gas compressor with the work generated by said
expansion of said first pressurized gas, wherein said first gas
compressor is located at said first site; c) removing a first
compressed gas from said first gas compressor; d) sending at least
part of said first compressed gas to a gas treatment unit, wherein:
1) said gas treatment unit is located at a second site; and 2) said
second site is located at least about 1 km away from said first
site; e) treating said first compressed gas in said gas treatment
unit; f) removing at least one fluid from said first compressed
gas; and g) sending at least part of said removed fluid from said
gas treatment unit to said first site.
2. The method of claim 1, wherein: a) said work generated by said
expansion of said first pressurized gas drives a first air
compressor, wherein said first air compressor is located at said
first site; b) a compressed air stream is removed from said first
air compressor; c) at least part of said compressed air stream is
sent to an air separation unit, wherein said air separation unit is
located at said second site; d) said air separation unit separates
air and at least one fluid enriched in a component of air is
removed from said unit; and e) at least part of said fluid enriched
in a component of air is sent to said first site.
3. The process of claim 1, wherein said first site is located at
least about 5 km away from said second site.
4. The method of claim 1, wherein said first compressed gas removed
from said first gas compressor has a pressure of at least about 8
bar.
5. The method of claim 4, wherein said first compressed gas has a
pressure of at least about 12 bar.
6. The process of claim 1, wherein said first pressurized gas is
steam.
7. The method of claim 1, wherein said first pressurized gas
comprises at least one member selected from the group consisting
of: a) air; and b) a hot gas produced by a combustor of a gas
turbine.
8. The method of claim 1, further comprising deriving said first
pressurized gas from a first process, wherein said first process
comprises at least one member selected from the group consisting
of: a) a fuel combustion process; b) a GTL process; c) a methanol
production process; d) a gas turbine process; and e) a DME
production process.
9. The method of claim 1, wherein said first process uses said
removed fluid.
10. The method of claim 1, wherein substantially all of said first
compressed gas is sent to said gas separation unit.
11. The method of claim 2, wherein: a) said gas treatment unit
comprises said air separation unit; b) air to be separated in said
air separation unit is first purified in a purification unit
located at said second site; c) all the streams of air sent from
said purification unit to said air separation unit have pressures
less than about 50 bar.
12. An apparatus which may be used for producing a fluid by gas
treatment, said apparatus comprising: a) a first process unit,
wherein said first process unit is located at a first site; b) a
first turbine, wherein: 1) said first turbine is located at said
first site; 2) said first turbine is coupled to at least a first
gas compressor; and 3) said first gas compressor is located at said
first site; c) a means for sending a gas derived from said first
process unit to said turbine; d) a gas treatment unit, wherein: 1)
said gas treatment unit is located at a second site; and 2) said
second site is located at least about 1 km away from said first
site; e) a first pipeline for sending gas from said first gas
compressor to said gas treatment unit; and f) a second pipeline for
sending a fluid removed from said gas treatment unit to said first
site.
13. The apparatus of claim 12, wherein said first pipeline and said
second pipeline run substantially parallel to each other over at
least part of their length.
14. The apparatus of claim 12, wherein: a) said gas treatment unit
is a distillation unit; b) said distillation unit comprises: 1) a
purifier for purifying a gas stream downstream of said first gas
compressor; and 2) a heat exchanger for bringing said purified gas
stream to a temperature suitable for distillation; and c) said
purifier and said heat exchanger are both located at said second
site.
15. The method of claim 1, further comprising: a) producing said
first compressed gas stream at said first site by a first
compression process, wherein said first compression process
comprises at least one first expansion step; b) producing a second
compressed gas stream at said first site by a second compression
process, wherein said second compression process comprises at least
one second expansion step; c) mixing said first compressed gas
stream and said second compressed gas stream to form a combined gas
stream; and d) sending said combined gas stream to an air
separation unit located at said second site.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. Non-Provisional
application Ser. No. 11/159,954 filed Jun. 23, 2005 which is a
Continuation-in-Part of U.S. Non-Provisional application Ser. No.
10/778,572, filed Feb. 13, 2004, the entire contents of which are
incorporated herein by reference.
BACKGROUND
[0002] Current natural gas reserves are often situated far from
world markets. Although it is possible to transport the natural
gas, in many cases it is preferred to convert the natural gas
fields in situ into more readily transportable products such as
synthetic fuels, methanol or dimethyl ether. The conversion
processes generally consume very large amounts of oxygen and
produce excess steam. Background for this field is to be found in
"Oxygen Facilities for Synthetic Fuel Projects", by W. J. Scharle
et al., Journal of Engineering for Industry, November 1981, Vol.
103, pp. 409-417, in "Fundamentals of Gas to Liquids" January 2003,
The Petroleum Economist Ltd, and in EP-A-0748763.
[0003] It is not always possible to construct an air separation
unit close to the site of the conversion process, for example for
environmental or economic reasons. In this case, the steam
generated is sent via a pipeline to the air separation unit site
and there it is expanded in a turbine coupled to the main
compressor of the air separation unit.
[0004] However, the cost of such steam pipelines is prohibitive
since the steam has to be maintained at a high temperature to
prevent condensation.
[0005] In some cases, there may be a number of processes, each
producing excess energy in the form of steam or another hot gas.
There may be insufficient energy available on the site of the
process to justify exporting that energy and the steam or other hot
gas may be vented to the atmosphere. Furthermore, the individual
processes may each produce a different grade of steam, such that
the two grades of steam cannot be sent to a single steam
turbine.
SUMMARY
[0006] It is an object of the present invention to provide a
process for separating air using the energy generated by a process
remote from the air separation unit.
[0007] This invention provides an integrated process and gas
treatment process wherein at least one first pressurized gas
derived from a first process at a first site is expanded. Using the
work generated by the expansion of at least one pressurized gas, a
first gas compressor at the first site is driven, operates, and
removes compressed gas from the first gas compressor. At least part
of the compressed gas from the first gas compressor is sent to a
gas treatment unit located at a remote second site. At least part
of the compressed gas sent from the first site to the second site
is treated in the gas treatment unit. At least one fluid from the
gas treatment unit is removed and at least part of the fluid
removed from the gas treatment unit is sent to the first site.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] For a further understanding of the nature and objects for
the present invention, reference should be made to the following
detailed description, taken in conjunction with the accompanying
drawings, in which like elements are given the same or analogous
reference numbers and wherein:
[0009] FIG. 1 illustrates one embodiment of the current invention,
which includes an integrated process and air separation unit;
[0010] FIG. 2 illustrates a second embodiment, which includes an
air separation unit integrated with two integrated processes;
and
[0011] FIG. 3 illustrates a third embodiment with an integrated
process and air separation unit.
[0012] The figures are not to scale.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] The term "partly pressurized" implies that the oxygen or
nitrogen streams may for example be pumped to a pressure less than
their required pressure and then vaporised at the second site
before entering the pipelines. Compressors at the first site
subsequently compress the nitrogen and oxygen to their required
final pressures, if needed.
[0014] FIG. 1 shows an integrated process and air separation
unit.
[0015] The integrated process unit 31 is located at a first site 1
and may for example be a GTL unit, for example comprising a Fischer
Tropsch unit, a methanol production unit, a DME production unit, a
fuel combustion unit such as a gas turbine or any unit producing
directly or indirectly steam or another hot gas.
[0016] The term "process unit" implies that a process takes place
at some location and at some time within the unit. However, the
unit itself does not necessarily operate according to a process,
which is globally exothermic.
[0017] The steam or other hot gas 39 is expanded in a turbine 33
(which may form part of process unit 31) located at the first site
1 and work from the turbine is transferred via coupling to an air
compressor 5. In this example, the air compressor 5 compresses only
air 7 to be sent to the air separation unit 21. The compressed air
19 is compressed to a pressure above 8 bars, preferably above 12
bars and is sent to the air separation unit 21 at a second site 2
at least 1 km away. It is nevertheless conceivable that compressed
air from the air compressor 5 could also be sent elsewhere, i.e.,
to another air separation unit.
[0018] Compressed air may also be sent to the air separation unit
21 from an air compressor 25 located at the second site 2.
[0019] Air to be separated in the air separation unit 21 is
purified in a purification unit at the second site and all the air
streams sent to the air separation unit 21 at the second site from
the purification unit at the second site are at pressures less than
50 bars.
[0020] A product gas 37 (which may be replaced by a product liquid)
coming from the air separation unit is also sent to another
pipeline running at least substantially parallel to the air
pipeline over at least part of its length, thereby saving civil
engineering costs. This gas, which may be nitrogen, oxygen or
argon, is unpressurized, partly pressurized or pressurized. Where
the gas is unpressurized or partly pressurized, it may be
compressed in a compressor 47 coupled to the turbine 33 at the
first site. The gas may then be used at the first site and may for
example be used in the process.
[0021] FIG. 2 shows an air separation unit 21 integrated with two
integrated processes. The first process unit 31 is as described
above with reference to FIG. 1. The further process unit 31A is
located at a third site 3, at least 1 km from the second site,
where the air separation unit 3 is located and, preferably, at
least 1 km from the first site. However, the further unit 31A may
be adjacent to the first site.
[0022] The further process unit 31A may operate according to the
same process as the first unit 31 or according to a different
process.
[0023] The unit 31A produces steam or another hot gas 39A, which is
expanded in turbine 33A. Gases 39 and 39A may both be steam but the
gas 39A may be steam having the same or different properties, i.e.,
the same or a different pressure as the gas 39 and/or the same or a
different temperature as the gas 39.
[0024] Air compressor 5A driven by turbine 33A supplies air 19A
only to the air separation unit via pipeline. The air 7A compressed
by compressor 5A is compressed to a pressure above 8 bars,
preferably above 12 bars.
[0025] Additionally, as in FIG. 1, there may a dedicated air
compressor at the second site 2.
[0026] Preferably, the pipelines 19, 19A, and the compressors 5 and
5A supply the air to the second site 2 at substantially the same
pressure so that only a single purification unit within the air
separation unit 21 is necessary. This may mean that the compressors
5 and 5A compress the air to substantially the same pressure, if
the pressure losses within the pipelines are substantially the
same. Alternatively, the compressors 5 and 5A may compress the air
to different pressures but the air arrives at the air separation
unit at substantially the same pressure from both pipelines due to
a judicious choice of the pipeline diameters and/or lengths and/or
the use of an expansion means, such as a valve.
[0027] If several purification means are provided, the air supplied
by the compressors 5 and 5A may arrive at the second site at
different pressures (due to different pressures at the compressor
outlets and/or different pressure drops within the pipeline
systems). In this case, the air pressures may be selected or
modified at the second site to correspond to pressures of different
columns of the air separation unit. For example, one air stream may
be purified at the pressure of the high pressure column of the air
separation unit whereas another air stream may be purified at the
pressure of an intermediate or low pressure column of the air
separation unit.
[0028] A product gas 37A coming from the air separation unit is
also sent to another pipeline running substantially parallel to the
air pipeline for air 19A over at least part of its length. This
gas, which may be nitrogen, oxygen or argon, is unpressurized,
partly pressurized, or pressurized. Where the gas is unpressurized
or partly pressurized, it may be compressed in a compressor coupled
to the turbine 33A at the third site. The gas may then be used at
the third site, for example in the process or another process.
[0029] Alternatively, the pipeline for air 19A may run
substantially parallel to the pipeline for air 19 over at least a
part of its length or may feed into that pipeline 19 (or vice versa
depending on where the sites 1, 2, 3 are).
[0030] Similarly, the pipeline for gas 37A may run substantially
parallel to the pipeline for gas 37 over at least a part of its
length or may feed into that pipeline 37 (or vice versa depending
on where the sites are) if the gases have substantially the same
purity or can be mixed to form a mixture having a required
composition.
[0031] At least one fluid produced by the air separation unit may
be sent to the first or third site or both.
[0032] The third site 3 may be contiguous with the second site 2,
less than 1 km from the second site, or at least 1 km from the
second site, and/or the third site 3 may be contiguous with the
first site 1, less than 1 km from the first site, or at least 1 km
from the first site.
[0033] The air separation unit may be of any known type. Ideally,
there should be no air compressor 25 located at the second site to
produce air for the air separation unit. All the feed air should
come from other sites. One example of an air separation process
well suited to this application is that of FIG. 1 of EP-A-0504029,
where all the air is compressed to a high pressure using a single
compressor.
[0034] It will be appreciated that a first stream of air may be
compressed using work from a first expansion step (such as a steam
turbine expansion) and a second stream of air may be compressed
using work from a second expansion step (such as a gas turbine
expansion), the first and second air streams may be mixed, possibly
after pressure equalisation and sent from the first site to the
second site.
[0035] FIG. 3 shows an integrated process and air separation
unit.
[0036] The integrated process unit 31 is located at a first site 1
and may for example be a GTL unit, for example comprising a Fischer
Tropsch unit, a methanol production unit, a DME production unit, a
fuel combustion unit such as a gas turbine or any unit producing
directly or indirectly steam or another hot gas.
[0037] The term "process unit" implies that a process takes place
at some location and at some time within the unit. However the unit
itself does not necessarily operate according to a process, which
is globally exothermic.
[0038] The steam or other hot gas 39 is expanded in a turbine 33
(which may form part of process unit 31) located at the first site
1 and work from the turbine is transferred via coupling to an air
compressor 5. In this example, the air compressor 5 compresses only
air 7 to be sent to the air separation unit 21. The compressed air
19 is compressed to a pressure above 8 bars, preferably above 12
bars and is sent to the air separation unit 21 at a second site 2
at least 1 km away. It is nevertheless conceivable that compressed
air from the air compressor 5 could be sent elsewhere, for example
to another air separation unit.
[0039] Compressed air is sent to the air separation unit 21 from an
air compressor 25 located at the second site 2. The air compressor
25 is driven by a turbine 33B, which expands gas 32B from a process
unit 31B at the second site. Air to be separated in the air
separation unit 21 is purified in a purification unit at the second
site and all the air streams sent to the air separation unit 21 at
the second site from the purification unit at the second site are
at pressures less than 50 bars.
[0040] A product gas 37 (which may be replaced by a product liquid)
coming from the air separation unit is also sent to another
pipeline running at least substantially parallel to the air
pipeline over at least part of its length, thereby saving civil
engineering costs. This gas, which may be nitrogen, oxygen or
argon, is unpressurized, partly pressurized or pressurized. Where
the gas is unpressurized or partly pressurized, it may be
compressed in a compressor 47 coupled to the turbine 33 at the
first site. The gas may then be used at the first site and may for
example be used in the process.
[0041] It will be understood that many additional changes in the
details, materials, steps and arrangement of parts, which have been
herein described in order to explain the nature of the invention,
may be made by those skilled in the art within the principle and
scope of the invention as expressed in the appended claims. Thus,
the present invention is not intended to be limited to the specific
embodiments in the examples given above.
* * * * *