CA1238651A - Method for the combined production of ammonia and urea - Google Patents
Method for the combined production of ammonia and ureaInfo
- Publication number
- CA1238651A CA1238651A CA000439716A CA439716A CA1238651A CA 1238651 A CA1238651 A CA 1238651A CA 000439716 A CA000439716 A CA 000439716A CA 439716 A CA439716 A CA 439716A CA 1238651 A CA1238651 A CA 1238651A
- Authority
- CA
- Canada
- Prior art keywords
- dioxide
- carbon
- solvent
- pressure
- heat
- 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
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
- C07C273/10—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds combined with the synthesis of ammonia
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Gas Separation By Absorption (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A description is given of a method for the combined production of ammonia and urea. An ammonia-synthesis gas, consisting mainly of hydrogen, nitrogen and carbon-dioxide, is subjected to pressurized washing, at temperatures equal to ambient temperature at the most, for the removal of acid contaminants, more particularly carbon-dioxide, with a physically acting solvent. The charged solvent is partly expanded for gassing out co-absorbed inerts, is then regener-ated without pressure, is returned to the pressurized wash, and the carbon-dioxide released during regeneration is used to synthesize urea. In order to be able to release this carbon-dioxide, in an energy-saving manner and pre-compressed to the urea installation, it is proposed that the pressure over the charged solvent be brought, after partial relief, to an intermediate value, that the charged solvent be heated for partial gassing out of carbon-dioxide, that the solvent thus partly regenerated be subjected to the final pressureless regenerating stage, and that the carbon-dioxide gassed out during heating be cooled and be released at the intermediate pressure.
A description is given of a method for the combined production of ammonia and urea. An ammonia-synthesis gas, consisting mainly of hydrogen, nitrogen and carbon-dioxide, is subjected to pressurized washing, at temperatures equal to ambient temperature at the most, for the removal of acid contaminants, more particularly carbon-dioxide, with a physically acting solvent. The charged solvent is partly expanded for gassing out co-absorbed inerts, is then regener-ated without pressure, is returned to the pressurized wash, and the carbon-dioxide released during regeneration is used to synthesize urea. In order to be able to release this carbon-dioxide, in an energy-saving manner and pre-compressed to the urea installation, it is proposed that the pressure over the charged solvent be brought, after partial relief, to an intermediate value, that the charged solvent be heated for partial gassing out of carbon-dioxide, that the solvent thus partly regenerated be subjected to the final pressureless regenerating stage, and that the carbon-dioxide gassed out during heating be cooled and be released at the intermediate pressure.
Description
165~
The invention relates to a method for combined production of ammonia and urea, whereby ammonia-synthesis gas, consisting mainly of hydrogen, nitrogen and carbon-dioxide, is subjected to pressurized washing, at temperatures equal to ambient temperature at the most, :Eor the removal of acid contaminants, more particularly carbon-dioxide, with a physi-cally acting solvent, whereupon the charged solvent is partly expanded for gassing out inerts, :is then regenerated without pressure, is returned to the pressurized wash, and the carbon-dioxide released during regeneration is used to synthesize urea.
As known from German Patent 27 21 462, for example, the synthesis of urea is based upon a mixture of hydrogen and nitrogen from which initially ammonia is obtained, and this is used to synthesize urea. The ammonia-synthesis gas, consisting mainly of hydrogen, nitrogen and carbon-dioxide is first sub-jected to a gas-wash for the removal of carbon-dioxide. In a subsequent regenerating column, carbon-dioxide is again released, without pressure, from the selective solvents in the washing column and is utilized for synthesing urea.
For subsequent urea-synthesis, however, this method has the disadvantage that the carbon-dioxide must be raised from atmospheric pressure to the urea-synthesis pressure of about 160 bars, and this requires a very large amount of energy.
It is therefore the purpose of the present invention to develop a method of the t~pe mentioned at the beginnlng hereof in such a manner that the released carbon-dioxide may be passed to the urea installation simply and inexpensively, i`.e.
in an energy-conserving manner, and pre-compressed, ~L23~6~i~
According to the invention, this purpose is achieved in that the pressure over the charged solvent is brought, after partial expansion, to an intermediate value, in that the charged solvent is heated for partial gassing out of carbon-dioxide, in that the solvent thus partlyregenerated is subjected to fina] pressureless regeneration, and in that the carbon-dioxide gassed out is cooled and is released at the intermediate pressure.
The invention is based upon the knowledge that physically dissolved carbon-dioxide can be at least partly gassed out of the solvent at pressures above atmospheric pressure, and that the higher the temperature of the solvent, and the lower the pressure, the larger the amount of carbon-dioxide gassed out.
The method according to the invention provides a considerable sa~ing in energy during subsequent urea-synthesis.
According to the invention, it is particularly advantageous for the pressure in at least one stage to be brought to an intermediate value of between 2 and 16, prefer-ably between ~ and 8 bars. Depending upon the pressure at which the washing is carried out, partial expansion for gassing out the inerts dissolved in the washing agent is carried out at a pressure corresponding to one third of the said washing pressure, for example.~ Depending upon this pressure, the charged washing agent is then expanded or pumped up to a pressure of between 2 and 16 bars. It is desirable that the charged solvent be then heated to a temperature of between 20 and 100, preferably between 50 and 90C. At these pressures ~L;23~65~
and tempera-tures proposed accordlng to the inven-tion, a considerable amount oE carbon-dioxide, namely between 50 and 90%, can be gassed out, and is thus ob-tained under pressure.
By using a plurality of expansion stages, some carbon-dioxide can be recovered at a still higher pressure, resulting in a still further reduction in the amount of energy needed to compress the carbon-dioxide.
According to another configuration of the method according to the invention, heating of the charged solvent is effected in heat-exchange with the degassed solvent and by means of waste-heat. This waste-heat may be taken from the "steam-reformer" for the production of ammonia synthesis gas and can be used profitably. It must therefore not be released to the atomosphere.
According to a preferred example of embodiment of the method according to the invention, the carbon-dioxide gassed out may be cooled in heat-exchange with the charge solvent which is to be heated. In this way, outside energy is also not required for cooling.
If the degree of purity of the washed gas is not required to be unduly high, i.e. if the residual charge in the regenerated solvent is not required to be unduly low, then, according to a further development of the concept of the invention, ex-tensive degassing may be carried out by expanding the so]vent to a low pressure of between 0.3 and 1, preferably between 0.5 and 0.7 bars, as the final regen-erating stage, the carbon-dioxide thus released being drawn off.
~;~3~
In order to tide over lnterruptions in the supply f C2 from the ammonia insta].lation or the CO2 compressor, provision is also made, according to the invention, for some of the carbon-dioxide gassed out at an intermediate pressure to be liquefied, for example in heat-exchange with evapora-ting NH3, and to be passed to a storage tank. This procedure has the advantage that, in the event of the above-mentioned interruptions, the urea installation can continue to operate for a certain length oE time.
The method according to the invention may be applied with al]. physical solvents, for example alcohols, ketones, N-methylpyrrolidone, polyethylene-glycol ether, dimethyl-formaide, glycols, or butyro-lactone.
I sui.table solvents are used, the pressurized washing may be carried out at lower temperatures in which case the coefficient of solubility of the components to be washed out increases to a known extent. This makes possible a considerable reduction in the amount of solvent. This in turn, makes it possible to use smaller pieces of eq~lipment resulting in lower ex~hange-losses~ for example in heat-exchangers. The same applies if washing is carried out at higher pressures.
Ammonia-synthesis is carried out at pressures in excess o~ 200 bars, so that fresh gas from a "steam-reformér"
at 30 bars must be raised to that pressure. Intermediate pressures may be 65 and 130 bars, for example. The entire amoun* of synthesis-gas, together with the carbon-dioxide, may be compressed to 65 bars, for example, and may be passed to ~;3 !3165~
t.he washing process at this pressure and at a reduced -temp-erature if necessary. Although compressing the carbon-dioxide requires energy, distinctly more carbon-dioxide is gassed out during the expansion and heating processes accord-ing to the invention, because of the smaller amount of solvent.
The energy pros and cons largely balance each other out, leaving the smaller amount of solvent as the decisive advant-age.
The method according to the invention is explained hereinafter in greater detail, in conjunction with the example of embodiment illustrated diagrammatically in the drawing attached hereto, wherein:
Fig. 1 is a diagram of the pressurized washing and subsequent regeneration processes;
Fig. 2 is an alternative for the final regeneration process;
Fig. 3 is an alternative for the partial expansion process.
According to Fig. 1, fission-gas, from an instal-.
lation for the production of ammonia-synthesis gas and con-taining contaminants such as acid gases and inerts such as Ar, CO and CH4, passes to the lower part of a washing column 2.
Physically-acting regenerated solvent is introduced into the upper part of the said washing column through line 3. The solvent, moving in counterflow to the ascending gas to be cleaned, absorbs the acid gases preferentially and is removed from the column-sump through line ~.
The puri~ied gas leaves the washing column at the top, through line 5.
~IL23~
Washin~ is carried ou-t at a pressure of 30 bars, for example, and at ambient temperature. The charged solvent is thus obtained at a pressure of 30 bars~
In addition to CO2, small amounts of ~2~ N2~ CO, CH4 and Ar are dissolved during washing. During regeneration, these components pass into the CO2. If, as in the present case, the concentration thereof in the degassed CO2 is to be kept as low as possible, the following circuit is provided:
the charged solvent is expanded (valve 6), for example to 10 bars~ This results in highly preferential degas~ing of H2, N2, CH4, CO and Ar. However, the pa.rtiall~r expanded gas still contains small amounts of CO2 and, for this reason, it is removed through line 8 from separator 7, is recompressed to the washing pressure by compressor 9, and is returned to the wash at the sump of column 2 through line 10.
This circulation of the inerts separates the co-dissolved components from the washing agent charged with CO2.
The partly expanded solvent lS removed through line 11 from the sump of separator 7 and is expanded, according to the invention, to an intermediate pressure of between 2 and 16 bars/ for example 5 bars (valve 12). At this pressure, the charged solvent is heated, in heat-exchanger 13 with the expanded solvent, and in a heat-exchanger 14 by means of waste-heat, for example from the "steam-reformer", for the purpose of producing the synthesis-gas, to a temperature of between 20 and 100C, for example 80C, and is passed to a separator 15. During the heating, there is a partial gassing out of CO2, the higher the temperature, the larger the amount , . -- 6 --~3~6~i~
f C2 yassed out. About 70~ of the CO2 is gassed out at abou-t 80C and 5 bars. This CO2 is removed through line 16, is cooled in heat exchanger 13 by the solvent to be heated, and is released at the intermediate pressuxe, through line 17, to a subsequent urea synthesis unit, not shown.
The solvent removed from separator 15 though line 1~
still contains residual CO2. The final regeneration, therefore, the partly regenerated solvent is passed to a regenerating column 19 which operates without pressure. The CO2 released during the expansion is the recovered pressureless from the top (line 20) and is discarded or compressed, if necessary.
The regenerated solvent leaves regenerating column 1 at the sump, is passed through line 21 to heat-exchanger 13 for cooling, and is delivered by a pump 22, through heat exchanger 23 and, if necessary, 2~, and through llne 3, to the top of washing column 2.
If the washed gas is not required to have unduly high CO2 purity, far~reaching degassing may be obtained by expanding the solvent to a low pressure of between 0.3 and 1 bar without further heating. This variant is illustrated diagrammatically in Fig. 2. The charged solvent from line 18 is expanded (valve 25) and is passed to vacuum-degassing unit 26. The CO2 thus released is drawn off by pump 27 and is further processed as described above. The regenerated ~
solvent leaves vacuum-degassing unit 2~ through line 21 and is pumped back (22~ to washing column 2, as already described.
The variant lllustrated in Fig. 3 is used to expand the solvent. According to this variant, the charged solvent ~:3~
is expanded, no-t through valve 6, but .in a hydraulie turbine 28. This allows electrical energy to be obtained ln aceord-anee with the drop in pressure. The expanded solvent is then passed, in the manner already described, to separator 7, the inerts are eirculated, and the charged solvent is subjeeted to further processing.
.. ~ ~ _
The invention relates to a method for combined production of ammonia and urea, whereby ammonia-synthesis gas, consisting mainly of hydrogen, nitrogen and carbon-dioxide, is subjected to pressurized washing, at temperatures equal to ambient temperature at the most, :Eor the removal of acid contaminants, more particularly carbon-dioxide, with a physi-cally acting solvent, whereupon the charged solvent is partly expanded for gassing out inerts, :is then regenerated without pressure, is returned to the pressurized wash, and the carbon-dioxide released during regeneration is used to synthesize urea.
As known from German Patent 27 21 462, for example, the synthesis of urea is based upon a mixture of hydrogen and nitrogen from which initially ammonia is obtained, and this is used to synthesize urea. The ammonia-synthesis gas, consisting mainly of hydrogen, nitrogen and carbon-dioxide is first sub-jected to a gas-wash for the removal of carbon-dioxide. In a subsequent regenerating column, carbon-dioxide is again released, without pressure, from the selective solvents in the washing column and is utilized for synthesing urea.
For subsequent urea-synthesis, however, this method has the disadvantage that the carbon-dioxide must be raised from atmospheric pressure to the urea-synthesis pressure of about 160 bars, and this requires a very large amount of energy.
It is therefore the purpose of the present invention to develop a method of the t~pe mentioned at the beginnlng hereof in such a manner that the released carbon-dioxide may be passed to the urea installation simply and inexpensively, i`.e.
in an energy-conserving manner, and pre-compressed, ~L23~6~i~
According to the invention, this purpose is achieved in that the pressure over the charged solvent is brought, after partial expansion, to an intermediate value, in that the charged solvent is heated for partial gassing out of carbon-dioxide, in that the solvent thus partlyregenerated is subjected to fina] pressureless regeneration, and in that the carbon-dioxide gassed out is cooled and is released at the intermediate pressure.
The invention is based upon the knowledge that physically dissolved carbon-dioxide can be at least partly gassed out of the solvent at pressures above atmospheric pressure, and that the higher the temperature of the solvent, and the lower the pressure, the larger the amount of carbon-dioxide gassed out.
The method according to the invention provides a considerable sa~ing in energy during subsequent urea-synthesis.
According to the invention, it is particularly advantageous for the pressure in at least one stage to be brought to an intermediate value of between 2 and 16, prefer-ably between ~ and 8 bars. Depending upon the pressure at which the washing is carried out, partial expansion for gassing out the inerts dissolved in the washing agent is carried out at a pressure corresponding to one third of the said washing pressure, for example.~ Depending upon this pressure, the charged washing agent is then expanded or pumped up to a pressure of between 2 and 16 bars. It is desirable that the charged solvent be then heated to a temperature of between 20 and 100, preferably between 50 and 90C. At these pressures ~L;23~65~
and tempera-tures proposed accordlng to the inven-tion, a considerable amount oE carbon-dioxide, namely between 50 and 90%, can be gassed out, and is thus ob-tained under pressure.
By using a plurality of expansion stages, some carbon-dioxide can be recovered at a still higher pressure, resulting in a still further reduction in the amount of energy needed to compress the carbon-dioxide.
According to another configuration of the method according to the invention, heating of the charged solvent is effected in heat-exchange with the degassed solvent and by means of waste-heat. This waste-heat may be taken from the "steam-reformer" for the production of ammonia synthesis gas and can be used profitably. It must therefore not be released to the atomosphere.
According to a preferred example of embodiment of the method according to the invention, the carbon-dioxide gassed out may be cooled in heat-exchange with the charge solvent which is to be heated. In this way, outside energy is also not required for cooling.
If the degree of purity of the washed gas is not required to be unduly high, i.e. if the residual charge in the regenerated solvent is not required to be unduly low, then, according to a further development of the concept of the invention, ex-tensive degassing may be carried out by expanding the so]vent to a low pressure of between 0.3 and 1, preferably between 0.5 and 0.7 bars, as the final regen-erating stage, the carbon-dioxide thus released being drawn off.
~;~3~
In order to tide over lnterruptions in the supply f C2 from the ammonia insta].lation or the CO2 compressor, provision is also made, according to the invention, for some of the carbon-dioxide gassed out at an intermediate pressure to be liquefied, for example in heat-exchange with evapora-ting NH3, and to be passed to a storage tank. This procedure has the advantage that, in the event of the above-mentioned interruptions, the urea installation can continue to operate for a certain length oE time.
The method according to the invention may be applied with al]. physical solvents, for example alcohols, ketones, N-methylpyrrolidone, polyethylene-glycol ether, dimethyl-formaide, glycols, or butyro-lactone.
I sui.table solvents are used, the pressurized washing may be carried out at lower temperatures in which case the coefficient of solubility of the components to be washed out increases to a known extent. This makes possible a considerable reduction in the amount of solvent. This in turn, makes it possible to use smaller pieces of eq~lipment resulting in lower ex~hange-losses~ for example in heat-exchangers. The same applies if washing is carried out at higher pressures.
Ammonia-synthesis is carried out at pressures in excess o~ 200 bars, so that fresh gas from a "steam-reformér"
at 30 bars must be raised to that pressure. Intermediate pressures may be 65 and 130 bars, for example. The entire amoun* of synthesis-gas, together with the carbon-dioxide, may be compressed to 65 bars, for example, and may be passed to ~;3 !3165~
t.he washing process at this pressure and at a reduced -temp-erature if necessary. Although compressing the carbon-dioxide requires energy, distinctly more carbon-dioxide is gassed out during the expansion and heating processes accord-ing to the invention, because of the smaller amount of solvent.
The energy pros and cons largely balance each other out, leaving the smaller amount of solvent as the decisive advant-age.
The method according to the invention is explained hereinafter in greater detail, in conjunction with the example of embodiment illustrated diagrammatically in the drawing attached hereto, wherein:
Fig. 1 is a diagram of the pressurized washing and subsequent regeneration processes;
Fig. 2 is an alternative for the final regeneration process;
Fig. 3 is an alternative for the partial expansion process.
According to Fig. 1, fission-gas, from an instal-.
lation for the production of ammonia-synthesis gas and con-taining contaminants such as acid gases and inerts such as Ar, CO and CH4, passes to the lower part of a washing column 2.
Physically-acting regenerated solvent is introduced into the upper part of the said washing column through line 3. The solvent, moving in counterflow to the ascending gas to be cleaned, absorbs the acid gases preferentially and is removed from the column-sump through line ~.
The puri~ied gas leaves the washing column at the top, through line 5.
~IL23~
Washin~ is carried ou-t at a pressure of 30 bars, for example, and at ambient temperature. The charged solvent is thus obtained at a pressure of 30 bars~
In addition to CO2, small amounts of ~2~ N2~ CO, CH4 and Ar are dissolved during washing. During regeneration, these components pass into the CO2. If, as in the present case, the concentration thereof in the degassed CO2 is to be kept as low as possible, the following circuit is provided:
the charged solvent is expanded (valve 6), for example to 10 bars~ This results in highly preferential degas~ing of H2, N2, CH4, CO and Ar. However, the pa.rtiall~r expanded gas still contains small amounts of CO2 and, for this reason, it is removed through line 8 from separator 7, is recompressed to the washing pressure by compressor 9, and is returned to the wash at the sump of column 2 through line 10.
This circulation of the inerts separates the co-dissolved components from the washing agent charged with CO2.
The partly expanded solvent lS removed through line 11 from the sump of separator 7 and is expanded, according to the invention, to an intermediate pressure of between 2 and 16 bars/ for example 5 bars (valve 12). At this pressure, the charged solvent is heated, in heat-exchanger 13 with the expanded solvent, and in a heat-exchanger 14 by means of waste-heat, for example from the "steam-reformer", for the purpose of producing the synthesis-gas, to a temperature of between 20 and 100C, for example 80C, and is passed to a separator 15. During the heating, there is a partial gassing out of CO2, the higher the temperature, the larger the amount , . -- 6 --~3~6~i~
f C2 yassed out. About 70~ of the CO2 is gassed out at abou-t 80C and 5 bars. This CO2 is removed through line 16, is cooled in heat exchanger 13 by the solvent to be heated, and is released at the intermediate pressuxe, through line 17, to a subsequent urea synthesis unit, not shown.
The solvent removed from separator 15 though line 1~
still contains residual CO2. The final regeneration, therefore, the partly regenerated solvent is passed to a regenerating column 19 which operates without pressure. The CO2 released during the expansion is the recovered pressureless from the top (line 20) and is discarded or compressed, if necessary.
The regenerated solvent leaves regenerating column 1 at the sump, is passed through line 21 to heat-exchanger 13 for cooling, and is delivered by a pump 22, through heat exchanger 23 and, if necessary, 2~, and through llne 3, to the top of washing column 2.
If the washed gas is not required to have unduly high CO2 purity, far~reaching degassing may be obtained by expanding the solvent to a low pressure of between 0.3 and 1 bar without further heating. This variant is illustrated diagrammatically in Fig. 2. The charged solvent from line 18 is expanded (valve 25) and is passed to vacuum-degassing unit 26. The CO2 thus released is drawn off by pump 27 and is further processed as described above. The regenerated ~
solvent leaves vacuum-degassing unit 2~ through line 21 and is pumped back (22~ to washing column 2, as already described.
The variant lllustrated in Fig. 3 is used to expand the solvent. According to this variant, the charged solvent ~:3~
is expanded, no-t through valve 6, but .in a hydraulie turbine 28. This allows electrical energy to be obtained ln aceord-anee with the drop in pressure. The expanded solvent is then passed, in the manner already described, to separator 7, the inerts are eirculated, and the charged solvent is subjeeted to further processing.
.. ~ ~ _
Claims (18)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for the combined production of ammonia and urea, whereby the ammonia-synthesis gas, consisting mainly of hydrogen, nitrogen and carbon-dioxide, is subjected to pressurized washing, at temperature equal to ambient temperature at the most, for the removal of acid contaminants, more particularly carbon-dioxide, with a physically acting solvent, whereupon the charged solvent is partly expanded for gassing out co-absorbed inerts, is then regenerated without pressure, is returned to the pressurized wash, and the carbon-dioxide released during regeneration is used to synthesize urea, characterized in that the pressure over the charged solvent is brought, after partial relief, to an intermediate value, in that the charged solvent is heated for partial gassing out of carbon-dioxide, that the solvent thus partly regenerated is subjected to the final pressureless regenerating stage, and in that the carbon-dioxide gassed out during heating is cooled and is released at the intermediate pressure.
2. A method according to claim 1, characterized in that the pressure in at least one stage is brought to an intermediate value of 2 to 16 bars.
3. A method according to claim 1, characterized in that the charged solvent is heated, for partial gassing out of CO2, to a temperature of between 20 and 100°C.
4. A method according to claim 2, characterized in that the charged solvent is heated, for partial gassing out of CO2, to a temperature of between 20 and 100°C.
5. A method according to one of claims 1 to 3, characterized in that heating of the charged solvent is carried out in heat-exchange with the expanded solvent and by means of waste-heat.
6. A method according to one of claims 1 to 3, characterized in that gassed out carbon-dioxide is cooled in heat exchange with the charged solvent to be heated.
7. A method according to one of claims 1 to 3, characterized in that the final regenerating stage is operated at a pressure of 0.3 to 1 bars, the resulting carbon-dioxide being drawn off.
8. A method according to one of claims 1 to 3, characterized in that part of the carbon-dioxide gassed out after partial gassing out is liquefied and passed to a storage tank.
9. A method according to claim 4, characterized in that heating of the charged solvent is carried out in heat-exchange with the expanded solvent and by means of waste-heat.
10. A method according to claim 4, characterized in that gassed out carbon-dioxide is cooled in heat exchange with the charged solvent to be heated.
11. A method according to one of claims 1 to 3, characterized in that gassed out carbon-dioxide is cooled in heat exchange with the charged solvent to be heated, and wherein heating of the charged solvent is carried out in heat-exchange with the expanded solvent and by means of waste-heat.
12. A method according to claim 4, characterized in that the final regenerating stage is operated at a pressure of 0.3 to 1 bars, the resulting carbon-dioxide being drawn off.
13. A method according to one of claims 1 to 3, characterized in that the final regenerating stage is operated at a pressure of 0.3 to 1 bars, the resulting carbon-dioxide being drawn off and heating of the charged solvent is carried out in heat-exchange with the expanded solvent and by means of waste-heat.
14. A method according to claim 10, characterized in that the final regenerating stage is operated at a pressure of 0.3 to 1 bars, the resulting carbon-dioxide being drawn off.
15. A method according to claim 4, 10, or 12, characterized in that part of the carbon-dioxide gassed out after partial gassing out is liquefied and passed to a storage tank.
16. A method according to claim 1, characterized in that the pressure in at least one stage is brought to an intermediate value of 4 to 8 bars.
17. A method according to claims 1 or 2, characterized in that the charged solvent is heated, for partial gassing out of CO2, to a temperature of between 50 to 90°C.
18. A method according to one of claims 1 to 3, characterized in that the final regenerating stage is operated at a pressure of .5 to .7 bars, the resulting carbon-dioxide being drawn off.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP3239605.8 | 1982-10-26 | ||
| DE19823239605 DE3239605A1 (en) | 1982-10-26 | 1982-10-26 | Process for the combined preparation of ammonia and urea |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1238651A true CA1238651A (en) | 1988-06-28 |
Family
ID=6176634
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000439716A Expired CA1238651A (en) | 1982-10-26 | 1983-10-26 | Method for the combined production of ammonia and urea |
Country Status (5)
| Country | Link |
|---|---|
| CA (1) | CA1238651A (en) |
| DE (1) | DE3239605A1 (en) |
| FR (1) | FR2534910B1 (en) |
| IN (1) | IN161573B (en) |
| ZA (1) | ZA837776B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10351518B2 (en) * | 2015-12-14 | 2019-07-16 | Thyssenkrupp Industrial Solutions Ag | Method for the provision of carbon dioxide for the synthesis of urea |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3401773A1 (en) * | 1984-01-19 | 1985-08-01 | Linde Ag, 6200 Wiesbaden | METHOD FOR SEPARATING AND SIMULTANEOUSLY DETERMINING ACID IMPURITIES FROM GAS MIXTURES |
| DE3401779A1 (en) * | 1984-01-19 | 1985-08-01 | Linde Ag, 6200 Wiesbaden | METHOD FOR THE COMBINED PRODUCTION OF AMMONIA AND UREA |
| NO874821L (en) * | 1986-12-02 | 1988-06-03 | Norton Co | PROCEDURE FOR AA REMOVING CARBON DIOXIDE FROM A GAS. |
| DE10055818A1 (en) | 2000-11-10 | 2002-05-23 | Ammonia Casale Sa | Catalytic production of ammonia, especially for direct conversion into urea, using nitrogen-hydrogen starting gas mixture obtained from natural gas by autothermal reforming and catalytic conversion |
| DE102016203277A1 (en) | 2016-02-29 | 2017-08-31 | Thyssenkrupp Ag | Integrated synthesis of ammonia and urea |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1540732A (en) * | 1966-10-14 | 1968-09-27 | Toyo Koatsu Ind Inc | Urea synthesis process |
| FR1541273A (en) * | 1966-10-25 | 1968-10-04 | Toyo Koatsu Ind Inc | Process for the treatment of unaltered urea synthesis substances |
| IT1060622B (en) * | 1976-05-14 | 1982-08-20 | Snam Progetti | PROCESS FOR THE REUSE OF PROCESS WATERS IN COMBINED PLANTS UREA AND AMMONIA |
-
1982
- 1982-10-26 DE DE19823239605 patent/DE3239605A1/en not_active Withdrawn
-
1983
- 1983-10-19 ZA ZA837776A patent/ZA837776B/en unknown
- 1983-10-25 FR FR8316960A patent/FR2534910B1/en not_active Expired
- 1983-10-26 CA CA000439716A patent/CA1238651A/en not_active Expired
- 1983-11-14 IN IN1386/CAL/83A patent/IN161573B/en unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US10351518B2 (en) * | 2015-12-14 | 2019-07-16 | Thyssenkrupp Industrial Solutions Ag | Method for the provision of carbon dioxide for the synthesis of urea |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2534910B1 (en) | 1985-07-19 |
| IN161573B (en) | 1987-12-26 |
| ZA837776B (en) | 1984-06-27 |
| FR2534910A1 (en) | 1984-04-27 |
| DE3239605A1 (en) | 1984-04-26 |
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