GB1574646A - Removal of co2 and/or h2s form gases - Google Patents
Removal of co2 and/or h2s form gases Download PDFInfo
- Publication number
- GB1574646A GB1574646A GB11542/77A GB1154277A GB1574646A GB 1574646 A GB1574646 A GB 1574646A GB 11542/77 A GB11542/77 A GB 11542/77A GB 1154277 A GB1154277 A GB 1154277A GB 1574646 A GB1574646 A GB 1574646A
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- GB
- United Kingdom
- Prior art keywords
- solvent
- gas
- mixture
- methyl isopropyl
- polyethylene glycol
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000007789 gas Substances 0.000 title claims description 43
- 239000002904 solvent Substances 0.000 claims description 58
- RWSOTUBLDIXVET-UHFFFAOYSA-N Dihydrogen sulfide Chemical compound S RWSOTUBLDIXVET-UHFFFAOYSA-N 0.000 claims description 36
- 229920001223 polyethylene glycol Polymers 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 22
- RMGHERXMTMUMMV-UHFFFAOYSA-N 2-methoxypropane Chemical class COC(C)C RMGHERXMTMUMMV-UHFFFAOYSA-N 0.000 claims description 21
- 239000000203 mixture Substances 0.000 claims description 15
- 239000002202 Polyethylene glycol Substances 0.000 claims description 11
- 239000002253 acid Substances 0.000 claims description 8
- 238000005406 washing Methods 0.000 claims description 8
- 239000000470 constituent Substances 0.000 claims description 7
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical class COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 claims description 6
- 239000003345 natural gas Substances 0.000 claims description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 5
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims description 5
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 4
- 238000009835 boiling Methods 0.000 claims description 3
- 239000003729 cation exchange resin Substances 0.000 claims description 3
- 229940023913 cation exchange resins Drugs 0.000 claims description 3
- -1 methyl isopropyl Chemical group 0.000 claims description 2
- 230000008929 regeneration Effects 0.000 claims description 2
- 238000011069 regeneration method Methods 0.000 claims description 2
- 229910000037 hydrogen sulfide Inorganic materials 0.000 claims 5
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims 1
- 229910002092 carbon dioxide Inorganic materials 0.000 claims 1
- 125000006353 oxyethylene group Chemical group 0.000 claims 1
- 239000006096 absorbing agent Substances 0.000 description 13
- 238000003795 desorption Methods 0.000 description 13
- 238000010521 absorption reaction Methods 0.000 description 11
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 8
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 7
- 150000005218 dimethyl ethers Chemical class 0.000 description 6
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- 150000001875 compounds Chemical class 0.000 description 5
- 150000002170 ethers Chemical class 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 238000000354 decomposition reaction Methods 0.000 description 4
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 description 4
- BZLVMXJERCGZMT-UHFFFAOYSA-N Methyl tert-butyl ether Chemical compound COC(C)(C)C BZLVMXJERCGZMT-UHFFFAOYSA-N 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- UWHCKJMYHZGTIT-UHFFFAOYSA-N tetraethylene glycol Chemical compound OCCOCCOCCOCCO UWHCKJMYHZGTIT-UHFFFAOYSA-N 0.000 description 3
- DHMQDGOQFOQNFH-UHFFFAOYSA-N Glycine Chemical compound NCC(O)=O DHMQDGOQFOQNFH-UHFFFAOYSA-N 0.000 description 2
- VQTUBCCKSQIDNK-UHFFFAOYSA-N Isobutene Chemical compound CC(C)=C VQTUBCCKSQIDNK-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- 239000004471 Glycine Substances 0.000 description 1
- QNAYBMKLOCPYGJ-REOHCLBHSA-N L-alanine Chemical compound C[C@H](N)C(O)=O QNAYBMKLOCPYGJ-REOHCLBHSA-N 0.000 description 1
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 235000004279 alanine Nutrition 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- CRVGTESFCCXCTH-UHFFFAOYSA-N methyl diethanolamine Chemical compound OCCN(C)CCO CRVGTESFCCXCTH-UHFFFAOYSA-N 0.000 description 1
- JLFNLZLINWHATN-UHFFFAOYSA-N pentaethylene glycol Chemical compound OCCOCCOCCOCCOCCO JLFNLZLINWHATN-UHFFFAOYSA-N 0.000 description 1
- 229920005990 polystyrene resin Polymers 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000012552 review Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 235000011149 sulphuric acid Nutrition 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/14—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by absorption
- B01D53/1493—Selection of liquid materials for use as absorbents
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/11—Purification; Separation; Use of additives by absorption, i.e. purification or separation of gaseous hydrocarbons with the aid of liquids
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/151—Reduction of greenhouse gas [GHG] emissions, e.g. CO2
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Water Supply & Treatment (AREA)
- General Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Gas Separation By Absorption (AREA)
- Treating Waste Gases (AREA)
- Industrial Gases (AREA)
- Detergent Compositions (AREA)
Description
(54) REMOVAL OF CO2 AND/OR H2S FROM GASES
(71) We, BASF AKTIENGESELL
SCHAFT, A German Joint Stock Company of 6700 Ludwigshafen, Federal Republic of
Germany, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following Statement:- The present invention relates to a process for removing H2S and/or CO2 from gases which contain these constituents, especially as impurities, by washing the gases with a solvent which contains as ether of a polyethylene glycol.
The use of organic solvents or aqueous solutions of organic solvents to remove undesired acid constituents, e.g. H2S and
CO2, from natural gases and synthesis gases, has been disclosed. A review article in
Hydrocarbon Processing, April 1975, pages 84-105, may be mentioned as representative of the extensive prior art.
The solvents for the selective removal of
H2S in the presence of CO2 comprise two groups. Firstly, there are chemical solvents, e.g. aqueous solutions of methyldiethanolamine and solutions of salts of a-aminocarboxylic acids, e.g. glycine or alanine (Alkazide), the selectivity of which is due to the fact that they dissolve 112S many times more rapidly than they dissolve CO2.
Secondly, there are physical solvents, e.g.
N-methylpyrrolidone (Purisole) and the dimethyl ethers of polyethylene glycols (Selexolg), which thermodynamically dissolve more H2S than CO2.
In addition to the solubility of a gas in a solvent, from which the minimum amounts of circulating solvent are calculated, the rate of solution of the gas in the solvent is of great importance, since it determines the size of the absorber.
The present invention seeks to provide a solvent for removing H2S and/or CO2 from gases, which solvent not only exhibits a high rate of solution of H2S but in which H2S is also adequately soluble.
The use of dimethyl ethers of polyethylene glycols or their mixtures to remove CO2 and/or H2S from gases is disclosed in U.S. Patents 2,649,166, 3,362,133 and 3,533,732. German Laid
Open Application DOS 2,263,980 discloses alkylpolyethylene glycol tert.-butyl ethers as solvents for acid gases.
It is true that as a rule the above solvents exhibit adequate absorption of H2S and/or Ò2 and also satisfactory viscosity chracteristics; according to the expèriments described in German Laid
Open Application DOS 2,263,980 the unsymmetrical ethers have somewhat higher absorption capacities than the dimethyl ethers described in the above U.S.
Patents. However, the rate of absorption of
H2S, both with dimethyl ethers and with methyl tert.-butyl ethers of polyethylene glycols, is not satisfactory in every case.
We have found, surprisingly, that good results may be achieved, in the washing of gases containing CO2 and/or H2S to remove these contaminants from them, by the use of the methyl isopropyl ether of a polyethylene glycol. Such an ether has in general a higher rate of solution of H2S than the conventional dimethyl ethers and alkyl tert.butyl ethers; it is therefore possible to choose a relatively smaller absorber.
Accordingly, the invention provides a process for removing CO2 and/or H2S from a gas which contains one or both or these constituents, by washing the gas under normal or superatmospheric pressure with a solvent comprising one or more polyethylene glycol methyl isopropyl ether containing from 2 to 8
units, followed by regeneration of the solvent.
Gases which may be purified in this way include coke oven gases, coal gasification gases, synthesis gases and, preferably, natural gases, from which H2S is to be removed selectively.
According to the invention, the methyl isopropyl ethers of polyethylene glycols of the following formula, which contain from 2 to 8 ethylene glycol groups (i.e. n=from 2 to 8) are used as the solvent:
The use of ethers with from 3 to 7 ethylene
glycol units is preferred; from the point of
view of the rate of solution of H2S, the
compound with 3 ethylene glycol units, i.e., the methyl isopropyl ether of triethylene
glycol, has proved best, whereas compounds
with 6 to 8 ethylene glycol units are more
suitable for removing CO2. However, in
practice, mixtures obtained by synthesizing
these compounds in the presence of strongly
acid cation exchange resins are as a rule
employed (cf. German Laid-open
Application DOS 25 44 569). If mixtures of
monomethyl ethers with 3 to 5 ethylene
glycol units are reacted with propylene in
accordance with German Laid-open
Application DOS 25 44 569 and the low
boiling constituents are removed, the
residual mixture of monomethyl ethers and
methyl isopropyl ethers may be employed as
the solvent.
As a rule, the solvents are employed in a
virtually anhydrous form. If steam stripping
is carried out in the desorption column, the
water content of the solvent should not
exceed 8% by weight, based on the solvent.
From the point of view of the ability to
dissolve CO2 and H2S, the methyl isopropyl ethers of polyethylene glycols behave like
physical solvents, i.e. Henry's law applies as
a good approximation, and thermo
dynamically more H2S than CO2 is
dissolved.
A process within the invention can be
carried out at normal or preferably super
atmospheric pressure, advantageously at
H2S partial pressures greater than 0.05 bar
and especially greater than 0.5 bar. When
removing CO2 from gases not containing
H2S, the CO2 partial pressure should
advantageously be greater than 4 bars and
especially greater than 10 bars. The washing
process may be carried out in one stage or
two stages. The choice of washing process
as a rule depends on the partial pressures of
the gases to be washed out and on the final
purity required, or in the permissible heat
consumption or stripper gas consumption.
A process within the invention may be
carried out either with a packed column or
with a column fitted with exchange trays.
The temperature of the solvent at the top of
the absorber should preferably not exceed 50"C. since the higher temperatures,
the lower is the gas loading of the solvent.
The absorption is as a rule carried out at
from 20 to 400C. The top temperature of the absorber is fixed in accordance with the conventional criteria and as a rule depends on the desired degree of purity and on the temperature of the cooling water.
The rich solvent can be flashed in one or more stages, e.g. using a flash turbine, and it may then be substantially regenerated in a packed desorption column or a desorption column equipped with trays, using stripping gas or steam which can be injected directly or can be generated by adding from 2 to 80% by weight; especially from 3 to 50/, by weight, of water to the solvent and employing indirect heat exchange. The solvent can also be stripped with an inert gas.
If, after flashing, the stripping is carried out in a column, it is advantageous to choose a pressure of from 1.1 to 1.5 bars in the main flashing stage.
The solvent running into the desorption column can be heated by means of the solvent discharged, in a countercurrent heat exchanger. The temperature at the bottom 'of the absorber as a rule is from 110 to 140"C, especially 115 to 1300C. The solvent may be conveyed by means of a pump to the top of the absorber via a cooler which can be used to set up the desired top temperature of the absorber.
If the wash is carried out in two stages, only a part of the solvent, coming from the desorption column, need be fed to the top of the absorber, while the remainder can be fed, at a somewhat higher temperature, to another point of the absorber as it comes from the main flashing stage (cf. Figure 2).
Figures 1 and 2 of the accompanying drawings show two preferred process flow charts for carrying out a one-stage wash and
a two-stage wash (rough wash and fine
wash), respectively.
Figure 1 shows a one-stage wash. This type
of wash is particularly suitable for gases with
low partial pressures of the components to be washed out.
A rough wash using a flashing circuit may
be carried out as follows (cf. Figure 1):
The gas to be washed is supplied through
line 11 to the absorption column 1 through which it flows from bottom to top
countercurrent to the solvent which is
charged at the top of the column. The washed (treated) gas leaves the absorption
column 1 at the top via line 12. The solvent loaded with sour gas leaves column 1 at the bottom and is flashed through a flash
turbine 4 into a flash column 2. It is then
supplied via heat exchanger 7 to the desorption column 3. The degassed solvent
leaves the desorption column at the bottom
and is forced by pump 5 via solvent cooler 9
into the top of the absorption column. The
flash gas from the flash stage leaves column
2 at the top through line 13. The off-gas from desorption column 3 leaves at the top and is then cooled in off-gas cooler 10. The heat balance of the wash is maintained by heat exchanger 8 at the bottom of column 3.
In the Figures, the numbers denote the following:
1. Absorption column
2. Flash column
3. Desorption column
4. Flash turbine
5. Solvent pump
6. Condensate pump
7. Solvent/solvent heat exchanger
8. Reboiler
9. Solvent cooler
10. Off-gas cooler
11. Crude gas
12. Treated gas
13. Flashing gas (inert gas+component
washed out)
14. Off-gas (component washed out)
Figure 2 shows a preferred flow diagram for two-stage washing (rough and fine washing) with one flashing stage and one desorption stage (stripper). The absorption column 1 comprises two sections 21 (rough wash) and 22 (fine wash). The solvent loaded with sour gas is flashed, as in Fig. 1, in turbine 4 and column 2. The solvent leaving flash column 2 at the bottom is divided into two streams. One portion of the stream goes to rough wash column 21 after passing through pump 25, while another portion of the flashed solvent passes through heat exchanger 7 to the top of desorption column 3. Reboiler 8 converts some of the solvent into vapor with which the solvent in column 3 is stripped from sour gas. The solvent stream thus regenerated is pumped by pump 5 through heat exchangers 7 and 9 for cooling, and then fed to fine wash column 22. The off-gas leaving at the top of desorption column 3 is cooled in offgas cooler 10.
In this Figure, the numbers denote the following:
21. Rough wash column
22. Fine wash column
25. Solvent pump 2.
In addition to their ability to dissolve H2S and CO2, the methyl isopropyl ethers of polyethylene glycols are able to absorb water. Hence, the solvents to be used according to the invention can also be used for conditioning natural gases. In that case, the water contained in the natural gas would be removed at the top of the stripper (compare position 3 in Figures 1 and 21. If the solvent of the invention is used for this purpose, the procedure followed would be as described in German Laid-Open
Application DOS 2,437,576, which proposes a process for conditioning natural gases by means of solvents other than those now proposed.
The present invention is illustrated by
Examples I and 2 which follow.
Comparative Example I compares the rate of absorption of H2S by methyl isopropyl ethers of polyethylene glycols with the rate of absorption by the ethers mentioned in
U.S. Patent 3,362,133 (e) and German Laid
Open Application DOS 2,263,980 (f), and
Comparative Example 2 the stability of the methyl tert.-butyl ethers of DOS 2,263,980 with the methyl isopropyl ethers of the invention.
EXAMPLE 1
Selective H2S removal
200 m3 (S.T.P.)/h of a dry synthesis gas at 16 bars and 50"C are supplied to a packed column of 0.3 m diameter packed to a height of 7.5 m. The composition of the gas is as follows (in /a by vol.): CO2 4.0
CO 46.8
CH4 0.2
n2 0.2
Ar 0.4
H2 48.0
H2S 0.4
COS 24 vol. ppm
The gas is washed countercurrently with 1.6 m3/h of a solvent comprising 90% w/w of asymmetrical methyl isopropyl ethers of polyethylene glycols [26 wt. /n tri, 36 tetra, 23 penta, 11 hexa and 4 hepta], 6% of similarly composed monomethyl ethers and 4% of water, the feed temperature being relatively unfavorable at 500 C. The treated gas leaving the top of the absorber contains 2.9 v/v CO2, 8 vol. ppm of COS and 0.8 vol. /a H2S. The wash liquid loaded with sour gas has a temperature of 51"C at the bottom of the absorber. It is regeberated by flashing to 1.25 bars and stripping with steam in a desorption column (bottoms temperature 130"C), allowed to cool to 500 and returned to the top of the absorber.
EXAMPLE 2
Joint removal of H2S and CO2
The method of Example 1 is followed, but 7 m3 (S.T.P.) wash liquid is used per hour.
At the top of the absorber the treated gas contains 1200 vol. ppm CO2, < 1 vol. ppm
H2S and < 8 vol. ppm COS.
COMPARATIVE EXAMPLE 1
Table 1 which follows shows the transfer coefficients Kg for the solvents of the invention and for various solvents of the prior art. The Kg values were determined in a jet stream chamber, the Kg value of the methyl isopropyl ether of triethylene glycol being taken arbitrarily as 1.
TABLE I
relative
mass
transfer (a) Methyl isopropyl ether of
triethylene glycol 1 (b) Methyl isopropyl ether of
tetraethylene glycol 0.86 (c) Methyl isopropyl ether of
pentaethylene glycol 0.79 (d) Undistilled mixture of A, B
and C 0.72 (e) Mixture of dimethyl ethers of
polyethylene glycols with low
boiling constituents 0.57 (f) Methyl tert.-butyl ether of
triethylene glycol 0.79 (g) Methyl tert.-butyl ether of
tetraethylene glycol 0.58
COMPARATIVE EXAMPLE 2
(a) Table 2 which follows shows the results of comparative experiments on the decomposition of the methyl tert.-butyl ether of tetraethylene glycol (A) and of the corresponding methyl isopropyl ether (B) with sulfuric acid. In each case, 30 g of the ether (A) or (B) were heated with 2 drops of concentrated sulfuric acid at 1400C (A) or 270"C (B only) for 1 hour. In the case of compound (B), a further 2 drops of concentrated sulfuric acid were afterward added at the higher temperature and the material was heated for a further 2 hours at 270"C. In each case, the isobutene or isopropylene eliminated was determined.
TABLE 2
Proportion decomposed A B in% Amount of concentrated H2SO4 2 2 4 l400C,afterlhour 100% 270"C after 1 hour 0 0 - after 3 hours ~ 2% Table 2 shows that the solvents to be used according to the invention are substantially more stable in an acid medium than the solvents of the prior art, as may be seen from the low degree of decomposition.
(b) In a further experiment, the rate of decomposition of the ethers (A) and (B) was determined. For this purpose, 100 g portions of the ethers were heated with 5% of the acid ion exchanger used for the manufacture of the ether (B) (a sulfonated crosslinked polystyrene resin in the H form) at 700 C, and the rate of elimination of olefins was measured. If the rate constant of the decomposition reaction for (B) is taken as = I, a value of 562 is found for the compounds (A) of the prior art.
Claims (13)
1. A process for removing CO2 and/or H2S from a gas which contain one or both of these constituents, by washing the gas under normal or superatmospheric pressure with a solvent comprising one or more polyethylene glycol methyl isopropyl ethers containing from 2 to 8
units, with subsequent regeneration of the solvent.
2. A process as claimed in claim 1, wherein hydrogen sulfide is selectively removed from natural gas.
3. A process as claimed in claim 1 or 2, wherein a solvent comprising a mixture of polyethylene glycol methyl isopropyl ethers containing from 2 to 8
units is used.
4. A process as claimed in claim I or 2, wherein a solvent comprising one or more polyethylene glycol methyl isopropyl ethers containing from 3 to 7
units are used.
5. A process as claimed in claim 1 or 2, wherein a solvent comprising a mixture of polyethylene glycol methyl isopropyl ethers. containing from 3 to 7
units is used.
6. A process as claimed in claim 3, wherein the mixture of polyethylene glycol methyl isopropyl ethers has been obtained by reacting a mixture of polyethylene glycol monomethyl ethers containing from 2 to 8
units in the presence of strongly acid cation exchange resins with propylene.
7. A process as claimed in claim 5, wherein the mixture of polyethylene glycol methyl isopropyl ethers has been obtained by reacting a mixture of polyethylene glycol monomethyl ethers containing from 3 to 7
units in the presence of strongly acid cation exchange resins with propylene.
8. A process as claimed in claim 1 or 2, wherein the methyl isopropyl mixture obtained by reacting a mixture of monomethyl ethers of polyethylene glycols of 3 to 5 oxyethylene units with propylene followed by removal of low-boiling constituents is used as solvent.
9. A process as claimed in.any of claims 1 to 8, wherein the solvent is employed in a virtually anhydrous form.
10. A process as claimed in any of claims 1 to 9, wherein the gas has an H2S partial pressure of greater than 0.05 bar or a CO2 partial pressure greater than 4 bars.
I I. A process as claimed in any of claims 1 to 10, carried out at from 20 to 400 C.
12. A process as claimed in claim I, carried out substantially as hereinbefore described with reference to Figure 1 or
Figure 2 of the accompanying drawings.
13. A process for removing H2S or CO2 and H2S from a gas containing it or them, carried out substantially as described in either of the foregoing Examples 1 and 2.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2611613A DE2611613B2 (en) | 1976-03-19 | 1976-03-19 | Process for the separation of CO2 and / or H25 from gases containing these components |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1574646A true GB1574646A (en) | 1980-09-10 |
Family
ID=5972880
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB11542/77A Expired GB1574646A (en) | 1976-03-19 | 1977-03-18 | Removal of co2 and/or h2s form gases |
Country Status (7)
| Country | Link |
|---|---|
| JP (1) | JPS5945034B2 (en) |
| BE (1) | BE852612A (en) |
| CA (1) | CA1091897A (en) |
| DE (1) | DE2611613B2 (en) |
| FR (1) | FR2344322A1 (en) |
| GB (1) | GB1574646A (en) |
| NL (1) | NL7702916A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2909335A1 (en) * | 1979-03-09 | 1980-09-18 | Linde Ag | METHOD AND DEVICE FOR DISASSEMBLING NATURAL GAS |
| DE2923012A1 (en) * | 1979-06-07 | 1980-12-18 | Basf Ag | METHOD FOR THE SIMULTANEOUS REMOVAL OF WATER AND SULFURIUM FROM GASES |
| US4741745A (en) * | 1986-05-07 | 1988-05-03 | Norton Company | Process for separation of carbon dioxide from other gases |
| JPH0698262B2 (en) * | 1987-11-06 | 1994-12-07 | 株式会社日本触媒 | Acid gas absorbent composition |
| US8435325B2 (en) * | 2008-10-23 | 2013-05-07 | Hitachi, Ltd. | Method and device for removing CO2 and H2S |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2139375A (en) * | 1937-06-14 | 1938-12-06 | Shell Dev | Removal of so from gases |
| US3591641A (en) * | 1968-10-28 | 1971-07-06 | Allied Chem | Production of dialkyl ethers of polyalkylene glycols |
| US3737392A (en) * | 1969-06-11 | 1973-06-05 | Allied Chem | Solvent composition useful in acid gas removal from gas mixtures |
| DE2544569C3 (en) * | 1975-10-04 | 1984-06-07 | Basf Ag, 6700 Ludwigshafen | Methyl isopropyl ether of tri-, tetra- and / or pentaethylene glycol |
-
1976
- 1976-03-19 DE DE2611613A patent/DE2611613B2/en not_active Withdrawn
-
1977
- 1977-02-21 CA CA272,392A patent/CA1091897A/en not_active Expired
- 1977-03-15 JP JP52027686A patent/JPS5945034B2/en not_active Expired
- 1977-03-17 NL NL7702916A patent/NL7702916A/en not_active Application Discontinuation
- 1977-03-18 BE BE852612A patent/BE852612A/en unknown
- 1977-03-18 FR FR7708184A patent/FR2344322A1/en active Granted
- 1977-03-18 GB GB11542/77A patent/GB1574646A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2611613A1 (en) | 1977-10-20 |
| JPS5945034B2 (en) | 1984-11-02 |
| DE2611613B2 (en) | 1979-04-26 |
| FR2344322B1 (en) | 1982-07-16 |
| JPS52125502A (en) | 1977-10-21 |
| BE852612A (en) | 1977-09-19 |
| FR2344322A1 (en) | 1977-10-14 |
| CA1091897A (en) | 1980-12-23 |
| NL7702916A (en) | 1977-09-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] | ||
| 746 | Register noted 'licences of right' (sect. 46/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |