CA2050407A1 - Process of desulfurizing a gas mixture which contains h2s, cos and co2 and scrubbing solution for use in that process - Google Patents
Process of desulfurizing a gas mixture which contains h2s, cos and co2 and scrubbing solution for use in that processInfo
- Publication number
- CA2050407A1 CA2050407A1 CA002050407A CA2050407A CA2050407A1 CA 2050407 A1 CA2050407 A1 CA 2050407A1 CA 002050407 A CA002050407 A CA 002050407A CA 2050407 A CA2050407 A CA 2050407A CA 2050407 A1 CA2050407 A1 CA 2050407A1
- Authority
- CA
- Canada
- Prior art keywords
- scrubbing
- zone
- solution
- cos
- scrubbing solution
- 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.)
- Abandoned
Links
- 238000005201 scrubbing Methods 0.000 title claims abstract description 77
- 239000000203 mixture Substances 0.000 title claims abstract description 29
- 238000000034 method Methods 0.000 title claims description 15
- 230000008569 process Effects 0.000 title claims description 15
- 230000003009 desulfurizing effect Effects 0.000 title claims description 4
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 30
- BAVYZALUXZFZLV-UHFFFAOYSA-N Methylamine Chemical compound NC BAVYZALUXZFZLV-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000003054 catalyst Substances 0.000 claims abstract description 12
- 230000007062 hydrolysis Effects 0.000 claims abstract description 11
- 238000006460 hydrolysis reaction Methods 0.000 claims abstract description 11
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 8
- 150000003951 lactams Chemical class 0.000 claims abstract description 5
- SECXISVLQFMRJM-UHFFFAOYSA-N N-Methylpyrrolidone Chemical compound CN1CCCC1=O SECXISVLQFMRJM-UHFFFAOYSA-N 0.000 claims description 5
- 230000001172 regenerating effect Effects 0.000 claims description 3
- XUWHAWMETYGRKB-UHFFFAOYSA-N piperidin-2-one Chemical compound O=C1CCCCN1 XUWHAWMETYGRKB-UHFFFAOYSA-N 0.000 claims description 2
- 150000004040 pyrrolidinones Chemical class 0.000 claims description 2
- 239000000243 solution Substances 0.000 description 28
- 239000007789 gas Substances 0.000 description 22
- 238000002474 experimental method Methods 0.000 description 11
- 230000003197 catalytic effect Effects 0.000 description 9
- 239000000126 substance Substances 0.000 description 8
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 6
- 238000009835 boiling Methods 0.000 description 4
- 230000008929 regeneration Effects 0.000 description 4
- 238000011069 regeneration method Methods 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 229910052717 sulfur Inorganic materials 0.000 description 2
- 239000011593 sulfur Substances 0.000 description 2
- 101100087530 Caenorhabditis elegans rom-1 gene Proteins 0.000 description 1
- 101100305983 Mus musculus Rom1 gene Proteins 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- OKKJLVBELUTLKV-UHFFFAOYSA-N methanol Substances OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 150000003335 secondary amines Chemical class 0.000 description 1
- 150000003512 tertiary amines Chemical class 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
- B01D53/1425—Regeneration of liquid absorbents
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Gas Separation By Absorption (AREA)
- Treating Waste Gases (AREA)
- Industrial Gases (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Detergent Compositions (AREA)
- Carbon And Carbon Compounds (AREA)
Abstract
ABSTRACT
The gas mixture is contacted in a scrubbing zone with a scrubbing solution which consists mainly of at least one N-alkylsubstituted lactam and contains 1 to 10 % by weight water. Temperatures in the range from 0 to 50 °C are maintained in the scrubbing zone.
Ammonia and/or methylamine is fed as a catalyst to the scrubbing zone at a rate of 5 to 100 moles per cubic meter of the scrubbing solution. As a result, at least 50% of the COS fed to the scrubbing zone are reacted by hydrolysis.
The gas mixture is contacted in a scrubbing zone with a scrubbing solution which consists mainly of at least one N-alkylsubstituted lactam and contains 1 to 10 % by weight water. Temperatures in the range from 0 to 50 °C are maintained in the scrubbing zone.
Ammonia and/or methylamine is fed as a catalyst to the scrubbing zone at a rate of 5 to 100 moles per cubic meter of the scrubbing solution. As a result, at least 50% of the COS fed to the scrubbing zone are reacted by hydrolysis.
Description
2 ~ 7 Metallgesellschaft AG Sept~mber 11, 1990 Reuterweg 14 6000 Frankfurt-on-Main 1 Case No. 89 00 26 Proces~ of De~ulfurizing a Ga~ Mixture Which aontains H2S, aos and C02 and Scrubbing Solution for Use in That Process DESCRIPTION
This invention relates -to a proce~s of desulfurizing a gas mixture which contains H2S, COS
and C02 by scrubbing in a scrubbing zone wi th a scrubbing 601ution which mainly consists of at lea~t one N-alkylsubstituted lactam and contains 1 to 10 % by weight water, wherein laden scrubbing ~olution is regenerated and is then re¢ycled to the scrubbing zone.
Processe~ o~ that kind are known and have been described, e.g., in Publi~hed German Application 30 00 250 and the corresponding U.S. Patent 4,368,059.
In that case a scrubbing solution is employed which in addition to an organic solvent contains per liter O.5 to 5 moles of one or more secondary or tertiary amines, which boil between 40 and 110 C at 1 bar~ The main component of the known scrubbing solution i~ preferably , ' . ' , , `, , .
~ 3~3 ~
`:
` - 2 -methanol. In the known process the amines serve mainly to .
improve the solubility of aos becau~e that solubility is usually much lower than the solubility of H2S.
:.~ In processes for a selective desulfurization of . gas mixtures which contain H2S9 COS and C02 with the physically acting known solvents the quantity of solvent which is circulated is usually determined by the content of COS, which has the lowest solubility of the sulfur-containing components of the ga~. But if COS can be reacted in the scrubbing zone by a hydrolysis with H20 in the reaction ~OS + H20 = H2S ~ C2 to form H2S and aO2, a ~maller quantity of solvent in circulation will be suf~icient. It is an object of the invention to elimi.nate COS at lea~t in part by a hydrolysis in the scrubbing zone and thu~ to : improve the economy and selecti~ity of the process.
:^ In the proce~s de~cribed fir~t hereinbefore that object is accomplished in accordance with the -` invention in that a temperature in the range from O
to 50 C i9 maintained in the scrubbing zone, ammonia and/or methylamine are fed as a catalyst to the scrubbing zone at a rate of about 5 to 100 mole~ and in most ca~es not in excess of 50 moles per cubic meter o~ the scrubbing ~olution, and at least 50% of the COS fed :. ."
'3 ~
This invention relates -to a proce~s of desulfurizing a gas mixture which contains H2S, COS
and C02 by scrubbing in a scrubbing zone wi th a scrubbing 601ution which mainly consists of at lea~t one N-alkylsubstituted lactam and contains 1 to 10 % by weight water, wherein laden scrubbing ~olution is regenerated and is then re¢ycled to the scrubbing zone.
Processe~ o~ that kind are known and have been described, e.g., in Publi~hed German Application 30 00 250 and the corresponding U.S. Patent 4,368,059.
In that case a scrubbing solution is employed which in addition to an organic solvent contains per liter O.5 to 5 moles of one or more secondary or tertiary amines, which boil between 40 and 110 C at 1 bar~ The main component of the known scrubbing solution i~ preferably , ' . ' , , `, , .
~ 3~3 ~
`:
` - 2 -methanol. In the known process the amines serve mainly to .
improve the solubility of aos becau~e that solubility is usually much lower than the solubility of H2S.
:.~ In processes for a selective desulfurization of . gas mixtures which contain H2S9 COS and C02 with the physically acting known solvents the quantity of solvent which is circulated is usually determined by the content of COS, which has the lowest solubility of the sulfur-containing components of the ga~. But if COS can be reacted in the scrubbing zone by a hydrolysis with H20 in the reaction ~OS + H20 = H2S ~ C2 to form H2S and aO2, a ~maller quantity of solvent in circulation will be suf~icient. It is an object of the invention to elimi.nate COS at lea~t in part by a hydrolysis in the scrubbing zone and thu~ to : improve the economy and selecti~ity of the process.
:^ In the proce~s de~cribed fir~t hereinbefore that object is accomplished in accordance with the -` invention in that a temperature in the range from O
to 50 C i9 maintained in the scrubbing zone, ammonia and/or methylamine are fed as a catalyst to the scrubbing zone at a rate of about 5 to 100 mole~ and in most ca~es not in excess of 50 moles per cubic meter o~ the scrubbing ~olution, and at least 50% of the COS fed :. ."
'3 ~
~ .
to the scrubbing zone is reacted in the scrubbing zone by hydrolysis.
It is known from EP~A-0 oo8 449 and DE-A-2 250 169 that the rate of the hydrolysis decreases as the temperature decreases and that the reaction will be frozen at temperatures below about 50GJ
Whereas the reaction of COS with H20 to form H2S + C02 i9 accelerated at higher temperatures7 this will be accompanied by an increaæe of the equilibrium residual content of aos.
It has surprisingly been found that said catalytic substances will preferably accelerate the hydrolysis of COS in the presence of relatively high concentrations of C02, Becau~e C02 is a reaction product of the hydrolysis of aos, it would have been expected that an increase of the C02 partial pressure will retard rather than accelerate the hydrolysis. The proces~ will be particularly recommendable if the C02 partial pressure in the scrubbing zone is at least 0.1 bar and preferably ~rom 1 to 20 bars. Under-such conditions the ~crubbing performed in acoordance with the invention will be highly selective because the rate of hydrolysis will be very high and the solubility of H2S in the scrubbing solution will be much higher than the solubility of C02. ~his i8 desirable because the load on the scrubber will be decreased and because the `~ .
,~ . , ,; : .
1' ' . ' ' , 2 ~ .3 7 ,. . ~
to the scrubbing zone is reacted in the scrubbing zone by hydrolysis.
It is known from EP~A-0 oo8 449 and DE-A-2 250 169 that the rate of the hydrolysis decreases as the temperature decreases and that the reaction will be frozen at temperatures below about 50GJ
Whereas the reaction of COS with H20 to form H2S + C02 i9 accelerated at higher temperatures7 this will be accompanied by an increaæe of the equilibrium residual content of aos.
It has surprisingly been found that said catalytic substances will preferably accelerate the hydrolysis of COS in the presence of relatively high concentrations of C02, Becau~e C02 is a reaction product of the hydrolysis of aos, it would have been expected that an increase of the C02 partial pressure will retard rather than accelerate the hydrolysis. The proces~ will be particularly recommendable if the C02 partial pressure in the scrubbing zone is at least 0.1 bar and preferably ~rom 1 to 20 bars. Under-such conditions the ~crubbing performed in acoordance with the invention will be highly selective because the rate of hydrolysis will be very high and the solubility of H2S in the scrubbing solution will be much higher than the solubility of C02. ~his i8 desirable because the load on the scrubber will be decreased and because the `~ .
,~ . , ,; : .
1' ' . ' ' , 2 ~ .3 7 ,. . ~
,, C2 will be left as a desired component in the pure gas.
The catalytic substance can be fed to the scrubbing zone together with the scrubbing solution although in most cases it will be desirable to feed the catalytic substance to the scrubbing zone separately from the scrubbing solution and downstream of the feeding point of the latter.
~ he catalytic substances will have a relatively low boiling point because ammonia (MH3) has a boiling point of -33.6C and methylamine (CH2NH3) has a boiling point of -6.3C.
This invention relates also to the scrubbing solution for deRulfurizing gas mixtures which contain H2S, aos and C02, which ~crubbing solution contains at least one N-alkylated lactam as a main component and contains ammonia and/or methylamine in an amount of 5 to 100 mole~ and in mo~t cases not in excess of 50 moles per cubic meter. Alternatively the catalytic sub~tance or the catalytic mixture of sub~tances may be fed to the scrubbing zone separately from the scrubbing solution.
Because the gas mixture to be desulfurized usually contains substantial quantities of aO2 ite aO2 content will be at least 0.5 time its H2S content. ~he scrubbing temperatures usually lie in the range from 0 to 50 C and in most cases from 20 to 40 C. The use of " :~ :
. ~ ... . t ..
.. ...
" :, ~J ~J if ~ ) 7 a lower temperature below 50C will increase the solubility of the sulfur-containing components of the gas and will thus improve the economy of the process.
For regenerating, a gas and vapor mixture which contains H2S and catalyst is expelled from the laden scrubbing solution and the catalyst is separated from that mixture and is recycled to the scrubbing zone.
~he regeneration is effected in known manner by pressure-relieving~ stripping and/or reboiling At least 50% of the ammonia and/or methylamine are stripped from the scrubbing solution by the regeneration and at least 90% o~ the catalytic substance are preferably ~tripped.
Because that substance is stripped by the regeneration, a substantial increase of the solubility of the acid gases will be prevented; such an increase o~ the solubility would adversely a~fect the regeneration.
The main component of the scrubbing solution may mainly consist of N-alkylated pyrrolidones or piperidones 9 such as N-methylpyrrolidone (NMP), which are known per se.
Further features o~ the process will be explained with re~erence to the drawing, which showe a flow scheme o~ the process.
~ he gas mixture which is to be deeulfuriæed contains H2S, COS and ¢2 and i~ supplied in line 1.
. .
.: .
That gas may consist, e.g., of a gas mixture which mainly consists of H2 and ao . The gas mixture is directly contacted in the scrubbing zone 2 with regenerated .. ~-.
scrubbing solution from line 3. The 6crubbing ~olution consists, e.g., of NMP and 3 to 6 % by weight water.
The scrubbing zone is also supplied through line 4 with ammonia and/or methylamine as a catalyst for the hydrolysis of COS. The scrubbing zone 2 contains elements known per se for promoting the mass transfer, such as liquid-permeable plates; such elements have been `~ `~
omitted in the drawing. Puri~ied gas is withdrawn in line 5 and has virtually completely been desulfurized but owing to the selectivity of the scrubbing solution contains a major portion of the original C02 content.
The laden ~crubbing solution contains H2S, C2 and a small amount of ~OS and leaves the scrubbing zone 2 in line 7 and is heated in the heat exchanger 8 and then flows in line 9 to the regenerating column 10.
In that column a reboiler 11 produces a vapor mixture by which the dissolved gases are stripped from the scrubbing solution. It is desira~le that the catalytic substances ;
have relatively low boiling points so that they will be almost entirely ~tripped in the column 10 at the temperatures in the range from 120 to 180 ~ prevailing therein. Regenerated scrubbing solution ~lows through ;;
:` :
2 c~f~ ~3 r j "! ~ 7 -- 7 -- .
line 3 and is cooled in the heat exchanger 8 and in an indirect cooler 6 before the solution return~ to the scrubbing zone 2.
~ he gas and vapor mixture which is discharged from the top of the column 10 in line 12 contains ~crubbing solution, catalytic substance, H2S, COS
and ao~. For a recovery from the mixture, the catalyst . may be separated by means not shown and may then be recycled in line 4.
EXAMPLE
: At a rate of 10 sm3 (am3 - standard cubic 'T` meter) per hour, a gas mixture is treated in a processing s~stem which i~ simpler than that shown in the drawing.
The gas mixture consists of H2 34 % by volume C2 31.5 ~ by volume . H2S 1.2 ~ by volume : COS 100 ppm C0 balance The gas mixture is treated at 30C and 5.5 MPa in a scrubbing column 2 ha~ing 60 plates with a scrubbing solution consisting of N-methylpyrrolidone and 6% by : weight water~ At a rate of 13.7 liters per hour, the scrubbing solution i~ fed onto the uppermost 60th plate o~ the column 2 and a catalyst ~olution, which in the fir~t experiment consi3t~ o~ an aqueou~ solution o~
'; ', . , . ', ' .
r~ ;S
ammonia is ~ed onto the 55th bottom. That solutionl which contains 17 grams r~3 (= 1 mole) per liter, i8 fed at a rate of 0.14 liter per hour~ As a re~ult, an NH3 concentration of 10 moles/m3 and a water content of 7% by weight are obtained in the scrubbing solution in the region between the first and 55th plate . The laden scrubbing solution is regenerated by being stripped and boiled whereby the NH3 content of the scrubbing solution decreases below 0~1 mole/m3 and the water content to 6% by weight. The regenerated scrubbing solution is pumped back to the scrubbing column and the NH3-containing condensate which is formed is removed. The desulfurized gas mixture leaves the scrubbing column in line 5 and still contains .., 28.5% by volume C02, 0.1 ppm H2S and 2 ppm aos.
' In a second experiment (control experiment) the NH3-containing catalyst solution is replaced by pure water, which is fed onto the 55th plate.
Under conditions which are the same in other respects to those used in the first experiment, the ga~ mixture obtained in line 5 now contains 0.5 ppm H2S, 22 ppm COS
and 28.5~o by volume C02 90 that the COS content is much higher than in the fir~t experiment.
In the third experiment an aqueous solution which contains 17 g NH3 and 62 g methylamine per liter is fed at a rate of 0.14 liter per hour onto the ' :
;''1, . , '', , " , ~
,: . . . .. .
. .:
g , 55th plate of the scrubbing column 2. This results in an NH3 concentra-tion of 10 mole/m3 and a methylamine concentration of 20 mole/m3 in the scrubbing ~olution .
in the region between the first and 55th plate As a result of a processing under conditions which are the same in other respects as in the first experi~ent) the gas mixture leaving the scrubbing column in line 5 contains 0.1 ppm H2S, 1.0 ppm COS and 28.5% by volume In a fourth experiment 9 only methylamine is contained in the catalyst solutionO ~hat ~olution, which contains 62 grams methylamine per liter, i5 fed at a rate of 0.14 l/h onto the 55th plate of the scrubbing column 2 so that a methylamine concen-tration of 20 mole/m3 is obtained in the scrubbing solution in the region between the first and 55th plate .
As a result of a processing under conditions which in other respects are the same a~ in the first experiment, the gas mixture in line 5 now contains 28.5% by volume C02, 0.1 ppm H2S and 7 ppm COS, i.e., much less H2S and aos than in the second experiment (control experiment).
In all experiments, significant amounts of H2 and C0 are not removed from the gas mixture.
, . . . .
The catalytic substance can be fed to the scrubbing zone together with the scrubbing solution although in most cases it will be desirable to feed the catalytic substance to the scrubbing zone separately from the scrubbing solution and downstream of the feeding point of the latter.
~ he catalytic substances will have a relatively low boiling point because ammonia (MH3) has a boiling point of -33.6C and methylamine (CH2NH3) has a boiling point of -6.3C.
This invention relates also to the scrubbing solution for deRulfurizing gas mixtures which contain H2S, aos and C02, which ~crubbing solution contains at least one N-alkylated lactam as a main component and contains ammonia and/or methylamine in an amount of 5 to 100 mole~ and in mo~t cases not in excess of 50 moles per cubic meter. Alternatively the catalytic sub~tance or the catalytic mixture of sub~tances may be fed to the scrubbing zone separately from the scrubbing solution.
Because the gas mixture to be desulfurized usually contains substantial quantities of aO2 ite aO2 content will be at least 0.5 time its H2S content. ~he scrubbing temperatures usually lie in the range from 0 to 50 C and in most cases from 20 to 40 C. The use of " :~ :
. ~ ... . t ..
.. ...
" :, ~J ~J if ~ ) 7 a lower temperature below 50C will increase the solubility of the sulfur-containing components of the gas and will thus improve the economy of the process.
For regenerating, a gas and vapor mixture which contains H2S and catalyst is expelled from the laden scrubbing solution and the catalyst is separated from that mixture and is recycled to the scrubbing zone.
~he regeneration is effected in known manner by pressure-relieving~ stripping and/or reboiling At least 50% of the ammonia and/or methylamine are stripped from the scrubbing solution by the regeneration and at least 90% o~ the catalytic substance are preferably ~tripped.
Because that substance is stripped by the regeneration, a substantial increase of the solubility of the acid gases will be prevented; such an increase o~ the solubility would adversely a~fect the regeneration.
The main component of the scrubbing solution may mainly consist of N-alkylated pyrrolidones or piperidones 9 such as N-methylpyrrolidone (NMP), which are known per se.
Further features o~ the process will be explained with re~erence to the drawing, which showe a flow scheme o~ the process.
~ he gas mixture which is to be deeulfuriæed contains H2S, COS and ¢2 and i~ supplied in line 1.
. .
.: .
That gas may consist, e.g., of a gas mixture which mainly consists of H2 and ao . The gas mixture is directly contacted in the scrubbing zone 2 with regenerated .. ~-.
scrubbing solution from line 3. The 6crubbing ~olution consists, e.g., of NMP and 3 to 6 % by weight water.
The scrubbing zone is also supplied through line 4 with ammonia and/or methylamine as a catalyst for the hydrolysis of COS. The scrubbing zone 2 contains elements known per se for promoting the mass transfer, such as liquid-permeable plates; such elements have been `~ `~
omitted in the drawing. Puri~ied gas is withdrawn in line 5 and has virtually completely been desulfurized but owing to the selectivity of the scrubbing solution contains a major portion of the original C02 content.
The laden ~crubbing solution contains H2S, C2 and a small amount of ~OS and leaves the scrubbing zone 2 in line 7 and is heated in the heat exchanger 8 and then flows in line 9 to the regenerating column 10.
In that column a reboiler 11 produces a vapor mixture by which the dissolved gases are stripped from the scrubbing solution. It is desira~le that the catalytic substances ;
have relatively low boiling points so that they will be almost entirely ~tripped in the column 10 at the temperatures in the range from 120 to 180 ~ prevailing therein. Regenerated scrubbing solution ~lows through ;;
:` :
2 c~f~ ~3 r j "! ~ 7 -- 7 -- .
line 3 and is cooled in the heat exchanger 8 and in an indirect cooler 6 before the solution return~ to the scrubbing zone 2.
~ he gas and vapor mixture which is discharged from the top of the column 10 in line 12 contains ~crubbing solution, catalytic substance, H2S, COS
and ao~. For a recovery from the mixture, the catalyst . may be separated by means not shown and may then be recycled in line 4.
EXAMPLE
: At a rate of 10 sm3 (am3 - standard cubic 'T` meter) per hour, a gas mixture is treated in a processing s~stem which i~ simpler than that shown in the drawing.
The gas mixture consists of H2 34 % by volume C2 31.5 ~ by volume . H2S 1.2 ~ by volume : COS 100 ppm C0 balance The gas mixture is treated at 30C and 5.5 MPa in a scrubbing column 2 ha~ing 60 plates with a scrubbing solution consisting of N-methylpyrrolidone and 6% by : weight water~ At a rate of 13.7 liters per hour, the scrubbing solution i~ fed onto the uppermost 60th plate o~ the column 2 and a catalyst ~olution, which in the fir~t experiment consi3t~ o~ an aqueou~ solution o~
'; ', . , . ', ' .
r~ ;S
ammonia is ~ed onto the 55th bottom. That solutionl which contains 17 grams r~3 (= 1 mole) per liter, i8 fed at a rate of 0.14 liter per hour~ As a re~ult, an NH3 concentration of 10 moles/m3 and a water content of 7% by weight are obtained in the scrubbing solution in the region between the first and 55th plate . The laden scrubbing solution is regenerated by being stripped and boiled whereby the NH3 content of the scrubbing solution decreases below 0~1 mole/m3 and the water content to 6% by weight. The regenerated scrubbing solution is pumped back to the scrubbing column and the NH3-containing condensate which is formed is removed. The desulfurized gas mixture leaves the scrubbing column in line 5 and still contains .., 28.5% by volume C02, 0.1 ppm H2S and 2 ppm aos.
' In a second experiment (control experiment) the NH3-containing catalyst solution is replaced by pure water, which is fed onto the 55th plate.
Under conditions which are the same in other respects to those used in the first experiment, the ga~ mixture obtained in line 5 now contains 0.5 ppm H2S, 22 ppm COS
and 28.5~o by volume C02 90 that the COS content is much higher than in the fir~t experiment.
In the third experiment an aqueous solution which contains 17 g NH3 and 62 g methylamine per liter is fed at a rate of 0.14 liter per hour onto the ' :
;''1, . , '', , " , ~
,: . . . .. .
. .:
g , 55th plate of the scrubbing column 2. This results in an NH3 concentra-tion of 10 mole/m3 and a methylamine concentration of 20 mole/m3 in the scrubbing ~olution .
in the region between the first and 55th plate As a result of a processing under conditions which are the same in other respects as in the first experi~ent) the gas mixture leaving the scrubbing column in line 5 contains 0.1 ppm H2S, 1.0 ppm COS and 28.5% by volume In a fourth experiment 9 only methylamine is contained in the catalyst solutionO ~hat ~olution, which contains 62 grams methylamine per liter, i5 fed at a rate of 0.14 l/h onto the 55th plate of the scrubbing column 2 so that a methylamine concen-tration of 20 mole/m3 is obtained in the scrubbing solution in the region between the first and 55th plate .
As a result of a processing under conditions which in other respects are the same a~ in the first experiment, the gas mixture in line 5 now contains 28.5% by volume C02, 0.1 ppm H2S and 7 ppm COS, i.e., much less H2S and aos than in the second experiment (control experiment).
In all experiments, significant amounts of H2 and C0 are not removed from the gas mixture.
, . . . .
Claims (6)
1. A process of desulfurizing a gas mixture which contains H2S, COS and CO2 by scrubbing in a scrubbing zone with a scrubbing solution which mainly consists of at least one N-alkylsubstituted lactam and contains 1 to 10% by weight water, wherein laden scrubbing solution is regenerated and is then recycled to the scrubbing zone, characterized in that a tempera-ture in the range from 0 to 50 °C is maintained in the scrubbing zone, ammonia and/or methylamine are fed as a catalyst to the scrubbing zone at a rate of about 5 to 100 moles and in most cases not in excess of 50 moles per cubic meter of the scrubbing solution, and at least 50% of the COS fed to the scrubbing zone is reacted in the scrubbing zone by hydrolysis.
2. A process according to claim 1, character-ized in that the gas mixture to be desulfurized which is fed to the scrubbing zone has a CO2 content which is at least 0.5 time its H2S content.
3. A process according to claim 1 or 2, characterized in that for regenerating, a gas and vapor mixture which contains H2S and catalyst is expelled from the laden scrubbing solution and the catalyst is separated from that mixture and is recycled to the scrubbing zone.
4. A process according to claim 1 or 2, or any of the following claims, characterized in that the scrubbing solution consists mainly of at least one N-alkylated pyrrolidone or piperidone.
5. A process according to claim 4, character-ized in that the scrubbing solution consists mainly of N-methylpyrrolidone.
6. A scrubbing solution for desulfurizing gas mixtures which contain H2S, COS and CO2, which scrubbing solution contains at least one N-alkylated lactam as a main component, characterized in that the scrubbing solution contains 5 to 100 moles ammonia and/or methyl-amine per cubic meter.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4028880.3 | 1990-09-12 | ||
| DE4028880A DE4028880A1 (en) | 1990-09-12 | 1990-09-12 | PROCESS FOR DISCHARGING A GAS MIXTURE CONTAINING H (ARROW ALARM) 2 (ARROW DOWN) S, COS AND CO (ARROW ALARM) 2 (ARROW DOWN), AND WASHING SOLUTION THEREOF |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2050407A1 true CA2050407A1 (en) | 1992-03-13 |
Family
ID=6414073
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002050407A Abandoned CA2050407A1 (en) | 1990-09-12 | 1991-08-30 | Process of desulfurizing a gas mixture which contains h2s, cos and co2 and scrubbing solution for use in that process |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0475487B1 (en) |
| JP (1) | JPH04247217A (en) |
| AT (1) | ATE105205T1 (en) |
| BR (1) | BR9103892A (en) |
| CA (1) | CA2050407A1 (en) |
| DE (2) | DE4028880A1 (en) |
| DK (1) | DK0475487T3 (en) |
| ES (1) | ES2052325T3 (en) |
| ZA (1) | ZA917272B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013120166A1 (en) * | 2012-02-17 | 2013-08-22 | Archon Technologies Ltd. | Process for the removal of sulfur compounds from gas streams |
| CN108506730A (en) * | 2018-05-09 | 2018-09-07 | 苏州卫鹏机电科技有限公司 | A kind of air supply system and its air supply method |
| CN110487851A (en) * | 2019-09-10 | 2019-11-22 | 华能国际电力股份有限公司 | A kind of measuring system and method for the hydrogen conductivity that deaerates |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4441796A1 (en) * | 1994-11-24 | 1996-05-30 | Binker Materialschutz Gmbh | Method for drawing off toxic gas and neutralising it |
| DE102008052612A1 (en) * | 2008-10-21 | 2010-04-22 | Uhde Gmbh | Wash solution for gas scrubbing with amines in aqueous ammonia solution and use |
| CN108479827B (en) * | 2018-04-03 | 2021-06-15 | 太原理工大学 | Medium-temperature hydrolysis conversion carbonyl sulfide and deoxygenation bifunctional coupling catalyst and preparation method |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1024412A (en) * | 1964-03-02 | 1966-03-30 | Shell Int Research | Removal of acidic gases from gaseous mixtures |
| US3777010A (en) * | 1971-06-21 | 1973-12-04 | Chevron Res | H2s removal |
| DE2250169A1 (en) * | 1972-10-13 | 1974-04-25 | Metallgesellschaft Ag | PROCESS FOR DESULFURIZATION OF TECHNICAL FUEL GASES AND SYNTHESIS GASES |
| CA1124038A (en) * | 1978-08-24 | 1982-05-25 | Glenn D. Correll | Hydrolysis of carbon oxysulfide with morpholines and piperazines |
| DE3000250A1 (en) * | 1980-01-05 | 1981-07-16 | Metallgesellschaft Ag, 6000 Frankfurt | METHOD FOR REMOVING H (DOWN ARROW) 2 (DOWN ARROW) S, CO (DOWN ARROW) 2 (DOWN ARROW), COS AND MERCAPTANES FROM GASES BY ABSORPTION |
| US4484934A (en) * | 1984-01-27 | 1984-11-27 | Combustion Engineering, Inc. | Physical solvent for gas sweetening |
-
1990
- 1990-09-12 DE DE4028880A patent/DE4028880A1/en active Granted
-
1991
- 1991-08-19 DK DK91202110.2T patent/DK0475487T3/en active
- 1991-08-19 DE DE59101561T patent/DE59101561D1/en not_active Expired - Fee Related
- 1991-08-19 ES ES91202110T patent/ES2052325T3/en not_active Expired - Lifetime
- 1991-08-19 EP EP91202110A patent/EP0475487B1/en not_active Expired - Lifetime
- 1991-08-19 AT AT9191202110T patent/ATE105205T1/en not_active IP Right Cessation
- 1991-08-27 JP JP3240370A patent/JPH04247217A/en active Pending
- 1991-08-30 CA CA002050407A patent/CA2050407A1/en not_active Abandoned
- 1991-09-10 BR BR919103892A patent/BR9103892A/en unknown
- 1991-09-12 ZA ZA917272A patent/ZA917272B/en unknown
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2013120166A1 (en) * | 2012-02-17 | 2013-08-22 | Archon Technologies Ltd. | Process for the removal of sulfur compounds from gas streams |
| CN104540577A (en) * | 2012-02-17 | 2015-04-22 | 亚康科技股份有限公司 | Process for the removal of sulfur compounds from gas streams |
| CN108506730A (en) * | 2018-05-09 | 2018-09-07 | 苏州卫鹏机电科技有限公司 | A kind of air supply system and its air supply method |
| CN110487851A (en) * | 2019-09-10 | 2019-11-22 | 华能国际电力股份有限公司 | A kind of measuring system and method for the hydrogen conductivity that deaerates |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04247217A (en) | 1992-09-03 |
| DE59101561D1 (en) | 1994-06-09 |
| EP0475487B1 (en) | 1994-05-04 |
| DE4028880A1 (en) | 1992-03-19 |
| DE4028880C2 (en) | 1993-02-25 |
| ATE105205T1 (en) | 1994-05-15 |
| BR9103892A (en) | 1992-05-26 |
| ES2052325T3 (en) | 1994-07-01 |
| DK0475487T3 (en) | 1994-06-13 |
| ZA917272B (en) | 1993-03-12 |
| EP0475487A1 (en) | 1992-03-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EEER | Examination request | ||
| FZDE | Discontinued |