CA1085590A - Process for the removal of acid gases - Google Patents
Process for the removal of acid gasesInfo
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- CA1085590A CA1085590A CA253,273A CA253273A CA1085590A CA 1085590 A CA1085590 A CA 1085590A CA 253273 A CA253273 A CA 253273A CA 1085590 A CA1085590 A CA 1085590A
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D19/00—Degasification of liquids
- B01D19/0005—Degasification of liquids with one or more auxiliary substances
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- 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
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- Engineering & Computer Science (AREA)
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- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Treating Waste Gases (AREA)
- Gas Separation By Absorption (AREA)
Abstract
A B S T R A C T
A process for the removal of acid gases from a gas or liquid mixture by contacting the said mixture with a solution containing water and an amine in which at least two alkanol groups which are bound to nitrogen are present, followed by the removal of the acid gases from the resulting acid gas-loaded solution by heating, in which process before the solution containing water and the amine is contacted with the said gas or liquid mixture, ouch a compound being added to this solution that during the removal of the acid gases by heating 0.1-15 mole % of the amine in the solution is present in the acid form.
A process for the removal of acid gases from a gas or liquid mixture by contacting the said mixture with a solution containing water and an amine in which at least two alkanol groups which are bound to nitrogen are present, followed by the removal of the acid gases from the resulting acid gas-loaded solution by heating, in which process before the solution containing water and the amine is contacted with the said gas or liquid mixture, ouch a compound being added to this solution that during the removal of the acid gases by heating 0.1-15 mole % of the amine in the solution is present in the acid form.
Description
108Ss9~
The invention relates to a process for the removal of acid gases from a gas or liquid mixture by contacting the said mixture with a solution containing water and an amine in which at least two alkanol groups which are bound to nitrogen are present, followed by the removal of the acid gases from the resulting acid gas-loaded solution by heating.
For many years aqueous solutions of di- and trialkanol amines have been used for the removal of acid gases, by which in this patent application are meant hydrogen sulphide and carbon dioxide and also compounds which are relatively easily convertible into ;hese materials such as carbon oxysulphide, from liquids, e.g. hydrocarbon mixtures, and in particular from gases, such as natural gas and refinery gases. These amines are very suitable to reduce to lower values the acid gas contents of the gases or liquids to be purified, also when the pressure of the gas to be purified is not high, e.g. atmospheric. The reduction of the content of acid gases, in particular H2S, to a minimum is becoming increasingly important owing to the environmental regulations imposed by the authorities. In this cGnnection mention may also be made, for example, of the removal of sulphur compounds from off-gases from sulphur-removal plants (in particular Claus plants) by converting all sulphur compounds in these off-gases into H2S, followed by intensive H2S-removal iO85590 from the resulting gas by means of the said amines until a gas having a very Low H2S content is obtained.
As already stated, the reduction to very low values of the acid gas content of the gases or liquids to be purified is quite possible. The regeneration of the amine solutions loaded with acid gases must be carried out thoroughly to the effect that the remaining content of ac d gases in the regenerated amine solution becomes so low that this solution can be re-used to reduce to the desired low values the acid-gas content of the gases to be purified.
This thorough regeneration requires much heat; steam is generally used as the source of this heat. It is considered a drawback that a large quantity of steam is necessary because the generation of steam is expensive.
It has now been found that the quantity Or steam required for the desired regeneration of the amine solution can be limited considerably if certain compounds are added to the amine solutions before the extraction of the acid gases from the mixtures to be purified. This not only makes the quantity of steam needed in order to obtain a very low residual quantity of acid gas in the regenerated amine solution smaller than in the conventional process, but also allows those parts ~ the plant where steam is produced and where the regeneration takesplace to be smaller-dimensioned, thus resulting in substantial capital savings.
10~35~90 In accordance with the present invention there is provided a process for the removal of acid gases from a gas or liquid mixture by contacting the said mixture with a solution containing water and an amine in which at least two alkanol groups which are bound to nitrogen are present, followed by the removal of the acid gases from the resulting acid gas-loaded solution by heating, characterized in that before said solution is contacted with the said mixture, sulphuric acid, an acid salt of sulphuric acid, oxalic acid, an acid salt of oxalic acid or a salt, of which the cation is removed from the ~olution before or during the heating step, is added to the solution in an amount such that during the removal of the acid gases by heating, 0.1 to 15 moleiO of the amine in the solution is present in the acid form.
In general the solutions containing water and an amine, in which at least two alkanol groups which are bound to nitrogen are present (which amine is referred to below as alkanol amine), will compri~e no substantial quantities of other compounds. It is al~o poqsible, however, that a con~iderable quantity of a physical solvent for acid gase~
i8 present, for example sulfolane, ~-methyl-pyrrolidone, propylene carbonate or methanol.
Suitable alkanol amines are secondary amines, such as diethanol amine and dipropanol amine, and in particular diisopropanol amine and tertiary amines, such as tri-ethanol amine and in particular methyl di-ethanol amine.
The quantities of the alkanol amine which are pre-sent in the aqueous solution may vary between wide limits.
These quantities are very suitably 10-70~o by weight in parti-cular 15-3~/o by weight, based on the total solution.
D _ 4 _ 1~855~0 The compound to be added serves to ensure that 0.1-15 mole % of the amine in the solution is in the acid form, i.e. the protonated form, during the removal of the acid gases from the loaded solution.
As the compound to be added use is very suitably made of an acid having a PK which under the conditions in which the acid gases are removed from the solution is lower than the PK Of the amine present which contains at least two alkanol amine groups which are bound to nitrogen, with the result that the amine is immediately converted into the acid form. Sulphuric acid and oxalic acid are particularly preferred.
By acids are, also meant acid salts, e,g. NaHSO4, thus the acid salts of sulphuric acid and oxa~ic acid may also be employed in accordance with the invention.
It is also possible to use acids the PK of which is higher than the PK of the amine; it will then be necessary to use an excess of equivalents of acid in order to convert a desired quantity of the amine into the acid form, It is of course also possible to add the acid together with an optionally equivalent quantity of an am~ne, in which two alkanol groups which are bound to nitrogen are p~esent, to the said solution. This amine is preferably the amine which is present in the solution as its main component.
~, 108~590 It is further possible that the compound to be added does not immediately result in the protonation of the amine, but that the said compound must be subjected to a conversion after addition to the said solution. The compound to be added is, for example, very suitably a salt of an acid of which salt the cation is removed from the solution before or during the heating step to remove the acid gases.
The æaid cation may, for example, be removed as a volatile base by evaporation. As examples of such cations may be mentioned cations of volatile amines (e.g. methyl amine, ethyl amine) and in particular ammonium. Ammonium sulphate is very suitably used as the compound to be added.
It is also possible to use as the compound to be added a salt of an acid the cation of which is removed by precipitation (possibly followed by filtration or centrifuging) before the heating step to remove the acid gases. Examples are salts of metals which have poorly soluble hydroxides, e.g.
aluminium, iron.
In this application, by "removal of a cation from the solution" is also mean~ the binding of the cation in the solution in such a way that the amine is converted into the acid form by means of the anion which is added as a salt together with the said cation. As an example of such a removal may be mentioned complexing of a cation, if desired only under the condîtions in which the regeneration of the acid gas-loaded solution is carried out.
The quantity of the said compound to be added to the above solution may vary. It will be best to determine empirically in each separate case what quantity of a certain compound results in an optimum saving in the amount of heat required for the regeneration of the ! B acid gas-loaded solution. In general the quantity of compound to be added will ~ 1-5 mole %, based on alkanol amine.
Removal of the acid gases from the gas mixtures to be purified and regeneration of the loaded alkanol amine solution may be carried out in conventional equipment for these operations, e.g. in absorption and regeneration columns p~ovided with trays. In a number of cases a somewhat larger number of trays will have to be used in the absorption column and/or regeneration column in the process according to the invention than in the conventional process (i.e. using an alkanol amine without the addition of the said compound), but the costs involved are amply compensated by savings in those parts of the plant where steam is produced and where the regeneration of the acid gas-loaded solution is carried out, and in the quantity of steam required.
In some cases the gases resulting from the process according to the invention have such a low H2S-content that they can be vented to the atmosphere without incineration.
This may in particular be the case for gases resulting from removal of H2S according to the invention from gases obtained by conversion into H2S of all sulphur compounds present in off-gases of sulphur-removal plants, in particular Claus plants.
1~85590 EXAMPLE I
a hydrocarbon gas mixture containing 7.2% by volume of H2S wa;. treated countercurrently with an aqueous solution containing 27% by weight of di-isopropanol amine at a pressure of 7 bar abs. and a temperature of 40C in an absorption column havin~ 15 valve trays.
The gas throu~hput rate was 230 Nm3/h, the liquid throughput rate 0.65 m3/h. The purified gas mixture contained H2S
in a quantity of 10 parts by volume per million (ppm).
The aqueous solution loaded with H2S was regenerated in a regeneration column having 16 valve trays by means of low-pressure steam of which 220 kg/m3 of the aqueous solution was required to remove therefrom such a quantity of H2S that the solution could be reused for the purification f the gas mixture to an H2S content of 10 ppm.
When a quantity of 0.015 mole of (NH4)2S04 or the same quantity of oxalic acid per mole of di-isopropanol amine had been added to the aqueous solution in advance, the quantity of steam required for the regeneration was found to be only 100 kg/m3 of the aqueous solution.
EXAMPLE II
The off-gas from a sulphur removal plant (Claus process) had the following composition:
H2S 0.4 %vol S2 0.2 "
COS O . 1 "
S (as S1) 0.1 "
C2 2.6 "
N2 64.6 "
H20 32.0 "
g This off-gas was heated and passed together with a gas containing H2 and C0 over a sulphided cobalt/
molybdenum on aluminil catalyst at 360~C. The resulting gas (in which substantially all of the S02, COS and S
originally present had been converted to H2S) was cooled to 40C in a cooling tower, in which the gas was contacted with a circulating water stream. The gas from the top of this column contained 1.1% by volume of H2S and 3.6%
by volume of C02. This stream was treated with 0.24 m3/h of an aqueous solution containing 25% by weight of di-isopropanol amine at 1.05 bar abs. and 40C in a column provided with 11 valve trays at a gas throughput rate of 95 Nm3/h. Upon regeneration of the loaded aqueous solution with 280 kg of steam per hour in a regeneration column provided with 16 valve trays, a purified gas with 225 ppm of H2S was obtained. When a quantity of 0.02 mole of (NH4)2S04 per mGle of di~isopropanol amine was added to the aqueous solution, a purified gas was found to be obtained which contained only 25 ppm of H2S at the same throughput rates and at the same quantity of steam used.
EXAMPLE III
A quantity of 250 Nm3/h of a gas mixture obtained in the gasification of oil, which gas mixture contained 0.5%
by volume of H2S and -4.5% by volume of C02, was treated with 0.32 m3~h of an aqueous solution containing 22%
by weight of methyl-di-ethanol amine at a pressure of 20 bar abs. and a temperature of 40C in a column with 20 valve trays, bringing the H2S content in the purified gas to 4 ppm. In order to obtain this amount of H2S a quantity of,50 kgth of ~team was necessary for the regeneration of the loaded solution in a column with 16 valve trays. When a quantity of 0.023 mole of H2SO4 per mole of methyl-di-et~anol amine was added in advance to the aqueous solution, a quantity of only 28 kg of steam~hour was found to be necessary to obtain a purified gas with 4 ppm of H2S under otherwise identical conditions.
EXAMPLE IV
A fresh aqueous solution of 209 k.moles di-isopropanol amine per m3 was loaded with H2S to a concentration of 0.14 mol H2S/mol di-isopropanol amine by bubbling pure H2S through the solution at ambient temperature. The loaded solution was heated to 90C and introduced at a rate of 4.05 kg/hr at the top of a regeneration column eqU~ed with 50 trays. The H2S was stripped from the solution with the aid o~ saturated steam which was introduced at a temperature of 103C at the bottom of the column at a rate of 0.52 kg/hr. The stripped solution was removed from the bottom of the column (comparative Experiment A).
Two experiments (B and C) were performed with the ~ same aqueous solution of di-isopropanolamine to which 5 0.02 k.moles H2SO4 per k.mole di-isopropanol amine had been added before loading with H2S. In the first experiment the oonditions used were the ~ame as those applied in . .
~0855~0 experiment A, in the second experiment the conditions differed in that the rate of saturated steam used was 0.~1 kg/hr.
In the table the H2S contents of the stripped solution and the rate of steam used are recorded. As can be seen less steam is needed to obtain nearly the same H2S content in case H2S04 is present in the solution of di-isopropanol amine (experiment C) or with the same amount of steam a much lower content of H2S in the stripped solution is obtained (experiment B).
Table .Experiment H S0 added to kg steam mol H2S/mol di-isopropanol a~in4e so.lution per hr. amine in stripped solution _ A No 0.52 0.0062 B Yes 0.52 0.0012 C Yes 0,31 0.0074 ;
The invention relates to a process for the removal of acid gases from a gas or liquid mixture by contacting the said mixture with a solution containing water and an amine in which at least two alkanol groups which are bound to nitrogen are present, followed by the removal of the acid gases from the resulting acid gas-loaded solution by heating.
For many years aqueous solutions of di- and trialkanol amines have been used for the removal of acid gases, by which in this patent application are meant hydrogen sulphide and carbon dioxide and also compounds which are relatively easily convertible into ;hese materials such as carbon oxysulphide, from liquids, e.g. hydrocarbon mixtures, and in particular from gases, such as natural gas and refinery gases. These amines are very suitable to reduce to lower values the acid gas contents of the gases or liquids to be purified, also when the pressure of the gas to be purified is not high, e.g. atmospheric. The reduction of the content of acid gases, in particular H2S, to a minimum is becoming increasingly important owing to the environmental regulations imposed by the authorities. In this cGnnection mention may also be made, for example, of the removal of sulphur compounds from off-gases from sulphur-removal plants (in particular Claus plants) by converting all sulphur compounds in these off-gases into H2S, followed by intensive H2S-removal iO85590 from the resulting gas by means of the said amines until a gas having a very Low H2S content is obtained.
As already stated, the reduction to very low values of the acid gas content of the gases or liquids to be purified is quite possible. The regeneration of the amine solutions loaded with acid gases must be carried out thoroughly to the effect that the remaining content of ac d gases in the regenerated amine solution becomes so low that this solution can be re-used to reduce to the desired low values the acid-gas content of the gases to be purified.
This thorough regeneration requires much heat; steam is generally used as the source of this heat. It is considered a drawback that a large quantity of steam is necessary because the generation of steam is expensive.
It has now been found that the quantity Or steam required for the desired regeneration of the amine solution can be limited considerably if certain compounds are added to the amine solutions before the extraction of the acid gases from the mixtures to be purified. This not only makes the quantity of steam needed in order to obtain a very low residual quantity of acid gas in the regenerated amine solution smaller than in the conventional process, but also allows those parts ~ the plant where steam is produced and where the regeneration takesplace to be smaller-dimensioned, thus resulting in substantial capital savings.
10~35~90 In accordance with the present invention there is provided a process for the removal of acid gases from a gas or liquid mixture by contacting the said mixture with a solution containing water and an amine in which at least two alkanol groups which are bound to nitrogen are present, followed by the removal of the acid gases from the resulting acid gas-loaded solution by heating, characterized in that before said solution is contacted with the said mixture, sulphuric acid, an acid salt of sulphuric acid, oxalic acid, an acid salt of oxalic acid or a salt, of which the cation is removed from the ~olution before or during the heating step, is added to the solution in an amount such that during the removal of the acid gases by heating, 0.1 to 15 moleiO of the amine in the solution is present in the acid form.
In general the solutions containing water and an amine, in which at least two alkanol groups which are bound to nitrogen are present (which amine is referred to below as alkanol amine), will compri~e no substantial quantities of other compounds. It is al~o poqsible, however, that a con~iderable quantity of a physical solvent for acid gase~
i8 present, for example sulfolane, ~-methyl-pyrrolidone, propylene carbonate or methanol.
Suitable alkanol amines are secondary amines, such as diethanol amine and dipropanol amine, and in particular diisopropanol amine and tertiary amines, such as tri-ethanol amine and in particular methyl di-ethanol amine.
The quantities of the alkanol amine which are pre-sent in the aqueous solution may vary between wide limits.
These quantities are very suitably 10-70~o by weight in parti-cular 15-3~/o by weight, based on the total solution.
D _ 4 _ 1~855~0 The compound to be added serves to ensure that 0.1-15 mole % of the amine in the solution is in the acid form, i.e. the protonated form, during the removal of the acid gases from the loaded solution.
As the compound to be added use is very suitably made of an acid having a PK which under the conditions in which the acid gases are removed from the solution is lower than the PK Of the amine present which contains at least two alkanol amine groups which are bound to nitrogen, with the result that the amine is immediately converted into the acid form. Sulphuric acid and oxalic acid are particularly preferred.
By acids are, also meant acid salts, e,g. NaHSO4, thus the acid salts of sulphuric acid and oxa~ic acid may also be employed in accordance with the invention.
It is also possible to use acids the PK of which is higher than the PK of the amine; it will then be necessary to use an excess of equivalents of acid in order to convert a desired quantity of the amine into the acid form, It is of course also possible to add the acid together with an optionally equivalent quantity of an am~ne, in which two alkanol groups which are bound to nitrogen are p~esent, to the said solution. This amine is preferably the amine which is present in the solution as its main component.
~, 108~590 It is further possible that the compound to be added does not immediately result in the protonation of the amine, but that the said compound must be subjected to a conversion after addition to the said solution. The compound to be added is, for example, very suitably a salt of an acid of which salt the cation is removed from the solution before or during the heating step to remove the acid gases.
The æaid cation may, for example, be removed as a volatile base by evaporation. As examples of such cations may be mentioned cations of volatile amines (e.g. methyl amine, ethyl amine) and in particular ammonium. Ammonium sulphate is very suitably used as the compound to be added.
It is also possible to use as the compound to be added a salt of an acid the cation of which is removed by precipitation (possibly followed by filtration or centrifuging) before the heating step to remove the acid gases. Examples are salts of metals which have poorly soluble hydroxides, e.g.
aluminium, iron.
In this application, by "removal of a cation from the solution" is also mean~ the binding of the cation in the solution in such a way that the amine is converted into the acid form by means of the anion which is added as a salt together with the said cation. As an example of such a removal may be mentioned complexing of a cation, if desired only under the condîtions in which the regeneration of the acid gas-loaded solution is carried out.
The quantity of the said compound to be added to the above solution may vary. It will be best to determine empirically in each separate case what quantity of a certain compound results in an optimum saving in the amount of heat required for the regeneration of the ! B acid gas-loaded solution. In general the quantity of compound to be added will ~ 1-5 mole %, based on alkanol amine.
Removal of the acid gases from the gas mixtures to be purified and regeneration of the loaded alkanol amine solution may be carried out in conventional equipment for these operations, e.g. in absorption and regeneration columns p~ovided with trays. In a number of cases a somewhat larger number of trays will have to be used in the absorption column and/or regeneration column in the process according to the invention than in the conventional process (i.e. using an alkanol amine without the addition of the said compound), but the costs involved are amply compensated by savings in those parts of the plant where steam is produced and where the regeneration of the acid gas-loaded solution is carried out, and in the quantity of steam required.
In some cases the gases resulting from the process according to the invention have such a low H2S-content that they can be vented to the atmosphere without incineration.
This may in particular be the case for gases resulting from removal of H2S according to the invention from gases obtained by conversion into H2S of all sulphur compounds present in off-gases of sulphur-removal plants, in particular Claus plants.
1~85590 EXAMPLE I
a hydrocarbon gas mixture containing 7.2% by volume of H2S wa;. treated countercurrently with an aqueous solution containing 27% by weight of di-isopropanol amine at a pressure of 7 bar abs. and a temperature of 40C in an absorption column havin~ 15 valve trays.
The gas throu~hput rate was 230 Nm3/h, the liquid throughput rate 0.65 m3/h. The purified gas mixture contained H2S
in a quantity of 10 parts by volume per million (ppm).
The aqueous solution loaded with H2S was regenerated in a regeneration column having 16 valve trays by means of low-pressure steam of which 220 kg/m3 of the aqueous solution was required to remove therefrom such a quantity of H2S that the solution could be reused for the purification f the gas mixture to an H2S content of 10 ppm.
When a quantity of 0.015 mole of (NH4)2S04 or the same quantity of oxalic acid per mole of di-isopropanol amine had been added to the aqueous solution in advance, the quantity of steam required for the regeneration was found to be only 100 kg/m3 of the aqueous solution.
EXAMPLE II
The off-gas from a sulphur removal plant (Claus process) had the following composition:
H2S 0.4 %vol S2 0.2 "
COS O . 1 "
S (as S1) 0.1 "
C2 2.6 "
N2 64.6 "
H20 32.0 "
g This off-gas was heated and passed together with a gas containing H2 and C0 over a sulphided cobalt/
molybdenum on aluminil catalyst at 360~C. The resulting gas (in which substantially all of the S02, COS and S
originally present had been converted to H2S) was cooled to 40C in a cooling tower, in which the gas was contacted with a circulating water stream. The gas from the top of this column contained 1.1% by volume of H2S and 3.6%
by volume of C02. This stream was treated with 0.24 m3/h of an aqueous solution containing 25% by weight of di-isopropanol amine at 1.05 bar abs. and 40C in a column provided with 11 valve trays at a gas throughput rate of 95 Nm3/h. Upon regeneration of the loaded aqueous solution with 280 kg of steam per hour in a regeneration column provided with 16 valve trays, a purified gas with 225 ppm of H2S was obtained. When a quantity of 0.02 mole of (NH4)2S04 per mGle of di~isopropanol amine was added to the aqueous solution, a purified gas was found to be obtained which contained only 25 ppm of H2S at the same throughput rates and at the same quantity of steam used.
EXAMPLE III
A quantity of 250 Nm3/h of a gas mixture obtained in the gasification of oil, which gas mixture contained 0.5%
by volume of H2S and -4.5% by volume of C02, was treated with 0.32 m3~h of an aqueous solution containing 22%
by weight of methyl-di-ethanol amine at a pressure of 20 bar abs. and a temperature of 40C in a column with 20 valve trays, bringing the H2S content in the purified gas to 4 ppm. In order to obtain this amount of H2S a quantity of,50 kgth of ~team was necessary for the regeneration of the loaded solution in a column with 16 valve trays. When a quantity of 0.023 mole of H2SO4 per mole of methyl-di-et~anol amine was added in advance to the aqueous solution, a quantity of only 28 kg of steam~hour was found to be necessary to obtain a purified gas with 4 ppm of H2S under otherwise identical conditions.
EXAMPLE IV
A fresh aqueous solution of 209 k.moles di-isopropanol amine per m3 was loaded with H2S to a concentration of 0.14 mol H2S/mol di-isopropanol amine by bubbling pure H2S through the solution at ambient temperature. The loaded solution was heated to 90C and introduced at a rate of 4.05 kg/hr at the top of a regeneration column eqU~ed with 50 trays. The H2S was stripped from the solution with the aid o~ saturated steam which was introduced at a temperature of 103C at the bottom of the column at a rate of 0.52 kg/hr. The stripped solution was removed from the bottom of the column (comparative Experiment A).
Two experiments (B and C) were performed with the ~ same aqueous solution of di-isopropanolamine to which 5 0.02 k.moles H2SO4 per k.mole di-isopropanol amine had been added before loading with H2S. In the first experiment the oonditions used were the ~ame as those applied in . .
~0855~0 experiment A, in the second experiment the conditions differed in that the rate of saturated steam used was 0.~1 kg/hr.
In the table the H2S contents of the stripped solution and the rate of steam used are recorded. As can be seen less steam is needed to obtain nearly the same H2S content in case H2S04 is present in the solution of di-isopropanol amine (experiment C) or with the same amount of steam a much lower content of H2S in the stripped solution is obtained (experiment B).
Table .Experiment H S0 added to kg steam mol H2S/mol di-isopropanol a~in4e so.lution per hr. amine in stripped solution _ A No 0.52 0.0062 B Yes 0.52 0.0012 C Yes 0,31 0.0074 ;
Claims (20)
1. A process for the removal of acid gases from a gas or liquid mixture by contacting the said mixture with a solution containing water and an amine in which at least two alkanol groups which are bound to nitrogen are present, followed by the removal of the acid gases from the resulting acid gas-loaded solution by heating, characterized in that before said solution is contacted with the said mixture, sulphuric acid, an acid salt of sulphuric acid, oxalic acid, an acid salt of oxalic acid or a salt, of which the cation is removed from the solution before or during the heating step, is added to the solution in an amount such that during the removal of the acid gases by heating, 0.1 to 15 mole % of the amine in the solution is present in the acid form.
2. A process as claimed in claim 1, in which sulphuric acid is added to said solution.
3. A process as claimed in claim 1, in which oxalic acid is added to said solution.
4. A process as claimed in claim 1, in which a salt is added to said solution, of which the cation is removed from the solution by evaporation.
5. A process as claimed in claim 4, characterized in that the salt is an ammonium salt.
6. A process as claimed in claim 5, characterized in that the ammonium salt is ammonium sulphate.
7. A process as claimed in claim 1, 2 or 3, characterized in that said amine is di-isopropanol amine.
8. A process as claimed in claim 4, 5 or 6, characterized in that said amine is di-isopropanol amine.
9. A process as claimed in claim 1, 2 or 3, characterized in that said amine is methyl di-ethanol amine.
10. A process as claimed in claim 4, 5 or 6, characterized in that said amine is methyl di-ethanol amine.
11. A process as claimed in claim 1, 2 or 3, characterized in that said amine is present in the solution in an amount of 15 to 30% by weight.
12. A process as claimed in claim 4, 5 or 6, characterized in that said amine is present in the solution in an amount of 15 to 30% by weight.
13. A process as claimed in claim 1, 2 or 3, characterized in that the sulphur acid or the oxalic acid or the salt is added in an amount of 1 to 5 mole % by weight based on the weight of the amine.
14. A process as claimed in claim 1, in which said salt is a salt of an acid selected from the group consisting of sulphuric acid and oxalic acid.
15. A process as claimed in claim 14, in which said cation is ammonium.
16. A process as claimed in claim 14, in which said cation is derived from a volatile amine.
17. A process as claimed in claim 1, wherein a salt is added to said solution and the cation of said salt is removed before said heating to remove the acid gases.
18. A process as claimed in claim 1, wherein a salt is added to said solution and the cation of said salt is removed during said heating to remove the acid gases.
19. A process as claimed in claim 1, in which an acid salt of sulphuric acid is added to said solution.
20. A process as claimed in claim 1, in which an acid salt of oxalic acid is added to said solution.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7507059 | 1975-06-13 | ||
| NL7507059A NL183225C (en) | 1975-06-13 | 1975-06-13 | METHOD FOR REMOVING ACID GASES FROM A GAS OR LIQUID MIXTURE USING AN AQUEOUS AMINE SOLUTION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1085590A true CA1085590A (en) | 1980-09-16 |
Family
ID=19823953
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA253,273A Expired CA1085590A (en) | 1975-06-13 | 1976-05-25 | Process for the removal of acid gases |
Country Status (10)
| Country | Link |
|---|---|
| JP (1) | JPS6036810B2 (en) |
| AU (1) | AU498094B2 (en) |
| BE (1) | BE842592A (en) |
| CA (1) | CA1085590A (en) |
| DE (1) | DE2626368A1 (en) |
| FR (1) | FR2313968A1 (en) |
| GB (1) | GB1547590A (en) |
| IT (1) | IT1070011B (en) |
| NL (1) | NL183225C (en) |
| SE (1) | SE419293B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1589231A (en) * | 1977-04-21 | 1981-05-07 | Shell Int Research | Process for the removal of acidic gases |
| ZA83242B (en) * | 1982-01-19 | 1983-11-30 | Ici Plc | The removal of hydrogen sulphide from gas streams |
| DE3236600A1 (en) * | 1982-10-02 | 1984-04-05 | Basf Ag, 6700 Ludwigshafen | METHOD FOR REMOVING CO (DOWN ARROW) 2 (DOWN ARROW) AND, IF NECESSARY, H (DOWN ARROW) 2 (DOWN ARROW) S FROM NATURAL GAS |
| JPS6048116A (en) * | 1983-06-30 | 1985-03-15 | ユニオン、カ−バイド、コ−ポレ−シヨン | Absorbent composition for removing acidic gas from gaseous mixture and its use |
| IT1191805B (en) * | 1986-06-11 | 1988-03-23 | Snam Progetti | PROCESS FOR SELECTIVE REMOVAL OF SULPHIDIC ACID |
| FR2996464B1 (en) | 2012-10-05 | 2015-10-16 | IFP Energies Nouvelles | METHOD FOR THE SELECTIVE ABSORPTION OF HYDROGEN SULFIDE FROM A GASEOUS EFFLUENT COMPRISING CARBON DIOXIDE BY AN AMINOUS ABSORBENT SOLUTION COMPRISING A VISCOSIFYING AGENT |
| FR3067352B1 (en) | 2017-06-09 | 2020-11-06 | Ifp Energies Now | NEW POLYAMINES, THEIR SYNTHESIS PROCESS AND THEIR USE FOR THE SELECTIVE REMOVAL OF H2S FROM A GASEOUS EFFLUENT CONTAINING CO2 |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2914469A (en) * | 1957-09-11 | 1959-11-24 | Tidewater Oil Company | Diethanolamine reclamation |
-
1975
- 1975-06-13 NL NL7507059A patent/NL183225C/en not_active IP Right Cessation
-
1976
- 1976-05-25 CA CA253,273A patent/CA1085590A/en not_active Expired
- 1976-06-04 BE BE1007431A patent/BE842592A/en not_active IP Right Cessation
- 1976-06-11 JP JP51067839A patent/JPS6036810B2/en not_active Expired
- 1976-06-11 DE DE19762626368 patent/DE2626368A1/en active Granted
- 1976-06-11 GB GB2433676A patent/GB1547590A/en not_active Expired
- 1976-06-11 IT IT2423876A patent/IT1070011B/en active
- 1976-06-11 SE SE7606654A patent/SE419293B/en not_active IP Right Cessation
- 1976-06-11 AU AU14824/76A patent/AU498094B2/en not_active Expired
- 1976-06-11 FR FR7617765A patent/FR2313968A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| NL183225B (en) | 1988-04-05 |
| JPS51151268A (en) | 1976-12-25 |
| DE2626368C2 (en) | 1989-04-27 |
| IT1070011B (en) | 1985-03-25 |
| GB1547590A (en) | 1979-06-20 |
| SE419293B (en) | 1981-07-27 |
| AU498094B2 (en) | 1979-02-08 |
| NL183225C (en) | 1988-09-01 |
| FR2313968B1 (en) | 1981-06-12 |
| FR2313968A1 (en) | 1977-01-07 |
| AU1482476A (en) | 1977-12-15 |
| SE7606654L (en) | 1976-12-14 |
| NL7507059A (en) | 1976-12-15 |
| BE842592A (en) | 1976-12-06 |
| DE2626368A1 (en) | 1976-12-23 |
| JPS6036810B2 (en) | 1985-08-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |