CA1334784C - Process for the production of ammonia from natural gas - Google Patents
Process for the production of ammonia from natural gasInfo
- Publication number
- CA1334784C CA1334784C CA000569167A CA569167A CA1334784C CA 1334784 C CA1334784 C CA 1334784C CA 000569167 A CA000569167 A CA 000569167A CA 569167 A CA569167 A CA 569167A CA 1334784 C CA1334784 C CA 1334784C
- Authority
- CA
- Canada
- Prior art keywords
- stream
- gas
- process according
- oxygen
- temperature
- 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 - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B3/00—Hydrogen; Gaseous mixtures containing hydrogen; Separation of hydrogen from mixtures containing it; Purification of hydrogen
- C01B3/02—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen
- C01B3/025—Preparation or purification of gas mixtures for ammonia synthesis
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/10—Process efficiency
- Y02P20/129—Energy recovery, e.g. by cogeneration, H2recovery or pressure recovery turbines
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Combustion & Propulsion (AREA)
- Inorganic Chemistry (AREA)
- Hydrogen, Water And Hydrids (AREA)
Abstract
The invention relates to a process for the production of ammonia from natural gas, liquified petroleum gas, naphtha or hydrogen-bearing gases, using a combined autothermic reforming process and feeding a separate oxygen stream and a separate stream of pre-heated air to the system. The aim of the inven-tion is to design an economical and simple configuration which reduces the oxygen requirement substantially.
The aim of the invention is achieved by implementing various process steps some of which are already known and by combining them in such a manner that, in addition to the atmospheric oxygen, a separate oxygen stream with a min. O2 concentration of 50% is admixed, the concentrated O2 stream being pre-heated to a max. temperature of 250°C and the atmos-pheric air stream to approx. 450 to 900°C, and the H2/N2 ratio required at the outlet of the reforming section being adjusted with the aid of the atmospheric air stream and the make-up oxygen stream.
The aim of the invention is achieved by implementing various process steps some of which are already known and by combining them in such a manner that, in addition to the atmospheric oxygen, a separate oxygen stream with a min. O2 concentration of 50% is admixed, the concentrated O2 stream being pre-heated to a max. temperature of 250°C and the atmos-pheric air stream to approx. 450 to 900°C, and the H2/N2 ratio required at the outlet of the reforming section being adjusted with the aid of the atmospheric air stream and the make-up oxygen stream.
Description
Process for the productlon of ammonia from natural gas The invention relates to a process for the production of ammonia from natural gas, liquified petroleum gas, naphtha or hydrogen-bearing gases, using a combined autothermic reformlng process and feeding a separate oxygen stream and a separate stream of pre-heated air to the system.
The known steam reforming processes for ammonia production can be divided into two main groups, i.e. processes using at least a part of the endothermic steam reforming step in a fired reactor where flue gas forms also at elevated pressures, and processes in which an entirely autothermic primary and secondary steam reforming takes place with the aid of partial oxidation of the treated gas stream.
The first group also lncludes processes using imported heated gas, for instance helium instead of the flue gas stream.
Processes in which a partial oxidation with only one catalytic steam reforming section upstream or downstream of or parallel to sald oxldation takes place, are not discussed because their configuration differs considerably from the processes covered in this application. Typical processes of this type have been disproved in DE-OS 32 45 088 and 33 43 114.
Processes of the flrst group in whlch at least a part of the catalytic steam reforming takes place in a fired reactor where flue gas forms, are for lnstance descrlbed in EP O
093 502. DE-OS 24 12 841 is typical for sald processes using imported hot gas instead of flue gas.
The known steam reforming processes for ammonia production can be divided into two main groups, i.e. processes using at least a part of the endothermic steam reforming step in a fired reactor where flue gas forms also at elevated pressures, and processes in which an entirely autothermic primary and secondary steam reforming takes place with the aid of partial oxidation of the treated gas stream.
The first group also lncludes processes using imported heated gas, for instance helium instead of the flue gas stream.
Processes in which a partial oxidation with only one catalytic steam reforming section upstream or downstream of or parallel to sald oxldation takes place, are not discussed because their configuration differs considerably from the processes covered in this application. Typical processes of this type have been disproved in DE-OS 32 45 088 and 33 43 114.
Processes of the flrst group in whlch at least a part of the catalytic steam reforming takes place in a fired reactor where flue gas forms, are for lnstance descrlbed in EP O
093 502. DE-OS 24 12 841 is typical for sald processes using imported hot gas instead of flue gas.
2 ~ ~47~4 27046-14 The inventlon relates to a process of the second group in which an entirely autothermic primary and secondary steam reformlng takes place wlth the ald of partlal oxldatlon of the treated gas stream.
Other state-of-the-art processes of this type are for instance described ln GB-A Z 153 382, US patent 4 666 680, DE-OS
35 32 413 and in the paper "Ammonla plant safety", volume 4, page 64 by Takeshl Mlyasugi et al.
The process descrlbed ln GB 2 153 382 and US patent 4 666 680 uses oxygen or oxygen-rlch alr wlth a mln. 2 content of 25 %, or preferably 35 %, for the generatlon of ammonla synthe-sls gas. The major economic aspect of thls process is the quan-tity of oxygen added to the alr whlle malntainlng the requlred H2/N2 ratlo and the resldual methane content ln the synthesls gas. Hence, sald quantlty of oxygen and the oxidatlon of a certain part of the gas stream from the prlmary reforming sectlon are crucial for the economy of said process. When the requlred composltlon of the gas leavlng the devlces described ln the above mentloned patents and the other process parameters are constant, the oxygen requlrement depends on the followlng:
a) the difference between the temperature of the lnlet gas mixture containlng hydrocarbons and steam and the temperature of the reformed gas stream from the above devlce;
b) the temperature of the oxidlzlng agent admlxed ln the partlal oxldatlon sectlon.
The temperature dlfference under a) can easlly be ~-~r optlmlzed from the economlc vlew-polnt but the temperature under - 1 33~
2a 27046-14 b) can only be lnfluenced to a certain extent ln vlew of the large oxldatlon potentlal (2 25 ./. 40 % by vol.) of the oxldl-zing agent. Moreover, heatlng requlres expenslve oxygen-compat-lble materlals. In ~B 2 153 382 lt is suggested that steam be added to the oxygen-rlch air to overcome these difflcultles but lt is obvious that make-up nitrogen and heat are withdrawn from the reactor, thus reducing the heat potential required for high process temperatures.
The aim of the invention ls to find an economical and simple process configuration permittlng ammonla productlon wlth the ald of a comblned autothermlc steam reformlng, thereby conslderably reduclng the oxygen requlrement and the lnput gas quantity.
~, 1 3~47~4 27046-l4 The inventlon Provldes a process for produclng ammonia from natural gas, llqulfled petroleum gas, naphtha or a hydrogen-hearlng gas ln a comblned autothermlc reformlng process whlch process provldes that ln addltlon to an atmospherlc oxygen-contalning alr stream, a separate oxygen stream wlth a mlnlmum oxygen content of 50% ls admlxed, the separate oxygen stream belng pre-heated to a maxlmum temperature of 250C and the atmospherlc alr stream to approxlmately 450-900C, and the H2/N2 ratlo requlred at the outlet of the reformlng sectlon belng ad~usted wlth the ald of the atmospherlc alr stream and/or make-up oxygen stream at the start of reformatlon.
In varlous preferred embodlments of the lnventlon:
(a) the dlfference between the lnlet temperature of a mlxture of steam and hydrocarbons and the outlet temperature of the reformed stream ls set to a value of c 150C;
(b) supply of the concentrated oxygen stream ls controlled as a functlon of the content of lmpurltles measured at the outlet of the flnal process step;
(c) desulphurlzatlon of feedstock, converslon of C0 to C02, C02 separatlon, separatlon of ammonla or hydrogen from synthesls gas and return to a related maln stream can be lmplemented upstream or downstream of autothermlc reformatlon;
~d) the temperature of the atmosphere alr stream ls malntalned at a constant value of approxlmately 700C and the oxygen stream at amblent temperature;
(e) methane content ls controlled at the outlet of a reformlng sectlon ln order to obtaln 0.2-3% by volume (preferably 1.3%);
t ~.~
(f) the H2/N2 ratio in synthesis gas is set to 2.1 - 2.9;
(g) imported fuel gas is fed to a partial oxidation section of a reforming stage;
(h) the H2O/C ratio of all streams fed to a reformer is maintained at a value of < 2.75, further steam being added to the gas stream flowing from a reforming section;
(i) the amount of N2 fed to a reformer is smaller than the quantity required stoichiometrically for NH3 formation in synthesis gas, an oxygen-bearing nitrogen stream being added in a selective CO oxidation section upstream of CO separation in order to adjust the required H2/N2 ratio;
/q rqe ~~
, (j) the amount of N2 fed to a reformer is sm~lcr than the quantity required stoichiometrically for NH3 formation in synthesis gas, the required H2/N2 ratio being adjusted ~s a low temperature purification section.
The preferred embodiments offer further advantages.
For instance, the make-up oxygen stream which contains more than 50~ oxygen depending on the oxygen source, is heated to a maximum temperature of 250 C. Said temperature should preferably correspond to the compressor outlet temperature but this oxygen stream may also be pre-heated with the aid of steam condensat-on .
The air is preferably heated at 450 - 900 C which is higher than the temperature of the reformed gas at the outlet of the autothermic section. The air can be heated by various methods but preferably by burning synthesis waste or tail gas in 5- 1 3 3 4 7 8 4 27046-l4 a superheater.
This high pre-heating temperature of the air stream which is voluminous compared with the oxygen stream, permits a substantial reduction of the overall oxygen requirement for the process and, consequently, it leads to savings in the supply of a concentrated oxygen stream and to lower input quantities of hydrocarbons.
It is known that a very high pre-heating temperature of the air stream may necessitate an overall supply of concentrat-ed oxygen of less than 17% compared with approximately 40%
in the case of a higher overall oxygen requirement (for ammonia production: GB 2 153 382). Particularly when using NH3 synthesis catalysts of the new generation operating at a synthesis pre-ssure of < 120 bar, the concentrated 2 stream may be omitted because of the lower H2/N2 ratio required and the residual methane content at the outlet of the steam reformlng sections exclusively controlled with the aid of the temperature of the pre-heated air at a constant H2/N2 ratio.
A further advantage of the process configuration according to the invention is that the control of the two ma~or process parameters, i.e. H2/N2 ratio and residual methane content, can be managed with systems of simple deslgn and lower degree of integration. The amount of concentrated 2 and the temperature of the pre-heated air stream can be used indepen-dently as control parameter for the residual methane content while the amount of air is primarlly suitable for the control of the H2/N2 ratlo.
It was found that it is possible to perform the cata-lytic steam reforming at a H2O/C ratio which causes a deficit of steam in the product gas stream which is subsequently treated in a catalytic CO conversion, i.e. a deficit of steam for the conversion. The consequences of said deficit are undesirable secondary reactions which, inter alia, cause a formation of hydrocarbons re-converted in the catalyst bed and a major pres-sure drop in the conversion section, said phenomena impairing the ammonia production.
Another advantage of the process configuration accor-ding to the lnventlon ls that a low H2O/C ratlo ls adjusted ln the autothermlc reformlng sectlon, thus favourably affectlng the oxygen requirement, and that the additional amount of steam required for the conversion ls added prlor to the conversion.
Therefore another advantage of this process is that no high-temperature waste gas streams are avallable on the process gas and flue gas sldes as ln the case of the conventional primary and secondary steam reformlng. In fact, the waste heat from the reforming section, conversion and synthesis is suffi-cient to generate steam but superheating of steam with the aid of process waste heat cannot be performed on an economical basis for turbines.
It is of course possible to burn fossil fuels and/or imported fuel gas in order to ensure efficient steam generation and supply for the compressor in the process plant. A combined steam and gas-turbine system is an alternative provided adequate fuels are available. The process according to the invention will be superior to any other process of this group if cheap electrical energy can be used.
Said process permits low-cost production of saturated steam which can be used as indicated below:
a) Installation of an absorption refrigerating system, using the cryogenic potential for - reducing the compressor capacity requirement by cooling the gases to be compressed;
- operating a physical C02 separation;
- drying the gases;
- gas fractionation by the low-temperature method.
b) Partial or complete absorption of the ammonia in the loop gas with the aid of water and single- or multi-stage desorption using steam, the loop gas which leaves the absorber and contains c1% by vol. NH3 being pre-cooled and then fed to a zeolite-operated dryer prior to re-heating and recycling to the converter. In this case, the loop-gas compressor is - 8 l 334784 27046-14 installed between absorber and dryer, the dryers being regenerated with a part stream of the dried loop gas.
All ammonia-bearlng streams are returned to the absorption/desorption system.
Accordlng to a speclal embodlment of the lnventlon, it is posslble to use part of the process heat for evaporating and superheating at least a part stream of the ammonla liquor from the absorber and to feed this stream to a turbine, the waste steam from said turbine being piped to the ammonia separation unit described under b). This turbine should be coupled to a generator or, if required, to the loop compressor and/or NH3 compressor.
It is of course possible to use process steam directly for desorption. Accordlng to another embodlment, the compressed process alr ls also sultable for burning gas not obtained in the primary steam reforming sectlon. If said gas is burnt outside the partial oxidation section lt ls recommended that the process steam be enriched by the necessary amount of oxygen prior to burning the make-up gas and that the amount be selected so as to permit the required pre-heating of the air. The product leaving the combustion chamber thus has an oxygen content which approxi-mates that of the ambient air. If purge gas from the synthesis loop is used in this case, the synthesis gas has a higher argon content which ls regarded as favourable for argon recovery.
The overall oxygen requirement in the autothermic steam reforming sectlon can be further reduced by the followlng method: The amount of nltrogen entrained into this section can be decreased by reduclng the alr feed rate below the value 8a l 334784 27046-14 required for the specified H2/N2 ratio in the product synthesis gas. Said ratlo would for lnstance be ad~usted with the aid of a selective catalytic CO oxidation (SELECTOXO process) upstream of the CO2 separatlon from the synthesls gas, an oxygen-bearlng nitrogen stream belng partlcularly sultable in thls case. The N2/H2 ratlo may also be ad~usted during the low-temperature purlflcatlon of the synthesls gas.
, ~ ~
Other state-of-the-art processes of this type are for instance described ln GB-A Z 153 382, US patent 4 666 680, DE-OS
35 32 413 and in the paper "Ammonla plant safety", volume 4, page 64 by Takeshl Mlyasugi et al.
The process descrlbed ln GB 2 153 382 and US patent 4 666 680 uses oxygen or oxygen-rlch alr wlth a mln. 2 content of 25 %, or preferably 35 %, for the generatlon of ammonla synthe-sls gas. The major economic aspect of thls process is the quan-tity of oxygen added to the alr whlle malntainlng the requlred H2/N2 ratlo and the resldual methane content ln the synthesls gas. Hence, sald quantlty of oxygen and the oxidatlon of a certain part of the gas stream from the prlmary reforming sectlon are crucial for the economy of said process. When the requlred composltlon of the gas leavlng the devlces described ln the above mentloned patents and the other process parameters are constant, the oxygen requlrement depends on the followlng:
a) the difference between the temperature of the lnlet gas mixture containlng hydrocarbons and steam and the temperature of the reformed gas stream from the above devlce;
b) the temperature of the oxidlzlng agent admlxed ln the partlal oxldatlon sectlon.
The temperature dlfference under a) can easlly be ~-~r optlmlzed from the economlc vlew-polnt but the temperature under - 1 33~
2a 27046-14 b) can only be lnfluenced to a certain extent ln vlew of the large oxldatlon potentlal (2 25 ./. 40 % by vol.) of the oxldl-zing agent. Moreover, heatlng requlres expenslve oxygen-compat-lble materlals. In ~B 2 153 382 lt is suggested that steam be added to the oxygen-rlch air to overcome these difflcultles but lt is obvious that make-up nitrogen and heat are withdrawn from the reactor, thus reducing the heat potential required for high process temperatures.
The aim of the invention ls to find an economical and simple process configuration permittlng ammonla productlon wlth the ald of a comblned autothermlc steam reformlng, thereby conslderably reduclng the oxygen requlrement and the lnput gas quantity.
~, 1 3~47~4 27046-l4 The inventlon Provldes a process for produclng ammonia from natural gas, llqulfled petroleum gas, naphtha or a hydrogen-hearlng gas ln a comblned autothermlc reformlng process whlch process provldes that ln addltlon to an atmospherlc oxygen-contalning alr stream, a separate oxygen stream wlth a mlnlmum oxygen content of 50% ls admlxed, the separate oxygen stream belng pre-heated to a maxlmum temperature of 250C and the atmospherlc alr stream to approxlmately 450-900C, and the H2/N2 ratlo requlred at the outlet of the reformlng sectlon belng ad~usted wlth the ald of the atmospherlc alr stream and/or make-up oxygen stream at the start of reformatlon.
In varlous preferred embodlments of the lnventlon:
(a) the dlfference between the lnlet temperature of a mlxture of steam and hydrocarbons and the outlet temperature of the reformed stream ls set to a value of c 150C;
(b) supply of the concentrated oxygen stream ls controlled as a functlon of the content of lmpurltles measured at the outlet of the flnal process step;
(c) desulphurlzatlon of feedstock, converslon of C0 to C02, C02 separatlon, separatlon of ammonla or hydrogen from synthesls gas and return to a related maln stream can be lmplemented upstream or downstream of autothermlc reformatlon;
~d) the temperature of the atmosphere alr stream ls malntalned at a constant value of approxlmately 700C and the oxygen stream at amblent temperature;
(e) methane content ls controlled at the outlet of a reformlng sectlon ln order to obtaln 0.2-3% by volume (preferably 1.3%);
t ~.~
(f) the H2/N2 ratio in synthesis gas is set to 2.1 - 2.9;
(g) imported fuel gas is fed to a partial oxidation section of a reforming stage;
(h) the H2O/C ratio of all streams fed to a reformer is maintained at a value of < 2.75, further steam being added to the gas stream flowing from a reforming section;
(i) the amount of N2 fed to a reformer is smaller than the quantity required stoichiometrically for NH3 formation in synthesis gas, an oxygen-bearing nitrogen stream being added in a selective CO oxidation section upstream of CO separation in order to adjust the required H2/N2 ratio;
/q rqe ~~
, (j) the amount of N2 fed to a reformer is sm~lcr than the quantity required stoichiometrically for NH3 formation in synthesis gas, the required H2/N2 ratio being adjusted ~s a low temperature purification section.
The preferred embodiments offer further advantages.
For instance, the make-up oxygen stream which contains more than 50~ oxygen depending on the oxygen source, is heated to a maximum temperature of 250 C. Said temperature should preferably correspond to the compressor outlet temperature but this oxygen stream may also be pre-heated with the aid of steam condensat-on .
The air is preferably heated at 450 - 900 C which is higher than the temperature of the reformed gas at the outlet of the autothermic section. The air can be heated by various methods but preferably by burning synthesis waste or tail gas in 5- 1 3 3 4 7 8 4 27046-l4 a superheater.
This high pre-heating temperature of the air stream which is voluminous compared with the oxygen stream, permits a substantial reduction of the overall oxygen requirement for the process and, consequently, it leads to savings in the supply of a concentrated oxygen stream and to lower input quantities of hydrocarbons.
It is known that a very high pre-heating temperature of the air stream may necessitate an overall supply of concentrat-ed oxygen of less than 17% compared with approximately 40%
in the case of a higher overall oxygen requirement (for ammonia production: GB 2 153 382). Particularly when using NH3 synthesis catalysts of the new generation operating at a synthesis pre-ssure of < 120 bar, the concentrated 2 stream may be omitted because of the lower H2/N2 ratio required and the residual methane content at the outlet of the steam reformlng sections exclusively controlled with the aid of the temperature of the pre-heated air at a constant H2/N2 ratio.
A further advantage of the process configuration according to the invention is that the control of the two ma~or process parameters, i.e. H2/N2 ratio and residual methane content, can be managed with systems of simple deslgn and lower degree of integration. The amount of concentrated 2 and the temperature of the pre-heated air stream can be used indepen-dently as control parameter for the residual methane content while the amount of air is primarlly suitable for the control of the H2/N2 ratlo.
It was found that it is possible to perform the cata-lytic steam reforming at a H2O/C ratio which causes a deficit of steam in the product gas stream which is subsequently treated in a catalytic CO conversion, i.e. a deficit of steam for the conversion. The consequences of said deficit are undesirable secondary reactions which, inter alia, cause a formation of hydrocarbons re-converted in the catalyst bed and a major pres-sure drop in the conversion section, said phenomena impairing the ammonia production.
Another advantage of the process configuration accor-ding to the lnventlon ls that a low H2O/C ratlo ls adjusted ln the autothermlc reformlng sectlon, thus favourably affectlng the oxygen requirement, and that the additional amount of steam required for the conversion ls added prlor to the conversion.
Therefore another advantage of this process is that no high-temperature waste gas streams are avallable on the process gas and flue gas sldes as ln the case of the conventional primary and secondary steam reformlng. In fact, the waste heat from the reforming section, conversion and synthesis is suffi-cient to generate steam but superheating of steam with the aid of process waste heat cannot be performed on an economical basis for turbines.
It is of course possible to burn fossil fuels and/or imported fuel gas in order to ensure efficient steam generation and supply for the compressor in the process plant. A combined steam and gas-turbine system is an alternative provided adequate fuels are available. The process according to the invention will be superior to any other process of this group if cheap electrical energy can be used.
Said process permits low-cost production of saturated steam which can be used as indicated below:
a) Installation of an absorption refrigerating system, using the cryogenic potential for - reducing the compressor capacity requirement by cooling the gases to be compressed;
- operating a physical C02 separation;
- drying the gases;
- gas fractionation by the low-temperature method.
b) Partial or complete absorption of the ammonia in the loop gas with the aid of water and single- or multi-stage desorption using steam, the loop gas which leaves the absorber and contains c1% by vol. NH3 being pre-cooled and then fed to a zeolite-operated dryer prior to re-heating and recycling to the converter. In this case, the loop-gas compressor is - 8 l 334784 27046-14 installed between absorber and dryer, the dryers being regenerated with a part stream of the dried loop gas.
All ammonia-bearlng streams are returned to the absorption/desorption system.
Accordlng to a speclal embodlment of the lnventlon, it is posslble to use part of the process heat for evaporating and superheating at least a part stream of the ammonla liquor from the absorber and to feed this stream to a turbine, the waste steam from said turbine being piped to the ammonia separation unit described under b). This turbine should be coupled to a generator or, if required, to the loop compressor and/or NH3 compressor.
It is of course possible to use process steam directly for desorption. Accordlng to another embodlment, the compressed process alr ls also sultable for burning gas not obtained in the primary steam reforming sectlon. If said gas is burnt outside the partial oxidation section lt ls recommended that the process steam be enriched by the necessary amount of oxygen prior to burning the make-up gas and that the amount be selected so as to permit the required pre-heating of the air. The product leaving the combustion chamber thus has an oxygen content which approxi-mates that of the ambient air. If purge gas from the synthesis loop is used in this case, the synthesis gas has a higher argon content which ls regarded as favourable for argon recovery.
The overall oxygen requirement in the autothermic steam reforming sectlon can be further reduced by the followlng method: The amount of nltrogen entrained into this section can be decreased by reduclng the alr feed rate below the value 8a l 334784 27046-14 required for the specified H2/N2 ratio in the product synthesis gas. Said ratlo would for lnstance be ad~usted with the aid of a selective catalytic CO oxidation (SELECTOXO process) upstream of the CO2 separatlon from the synthesls gas, an oxygen-bearlng nitrogen stream belng partlcularly sultable in thls case. The N2/H2 ratlo may also be ad~usted during the low-temperature purlflcatlon of the synthesls gas.
, ~ ~
Claims (14)
1. Process for producing ammonia from natural gas, liquified petroleum gas, naphtha or a hydrogen-bearing gas, and preheated air and a separate oxygen stream in a combined auto-thermic reforming process which process comprises controlling the H2/N2 ratio at the outlet of a reforming section by adjusting the amount of (a) a separate oxygen stream with a minimum oxygen content of 50% preheated to a maximum temperature of 250°C and (b) an atmospheric air stream preheated to a temperature of 450-900°C
at the start of reformation.
at the start of reformation.
2. Process according to claim 1, wherein the difference between the inlet temperature of a mixture of steam and hydro-carbons and the outlet temperature of the reformed stream is set to a value of < 150°C.
3. Process according to claim 1, wherein supply of the concentrated oxygen stream is controlled as a function of the content of impurities measured at the outlet of the final process step.
4. Process according to claim 1, 2 or 3, wherein at least one process step selected from desulphurization of feedstock, conversion of CO to CO2, CO2 separation, separation of ammonia or hydrogen from synthesis gas and return to a related main stream, is implemented upstream or downstream of autothermic reformation.
5. Process according to claim 1, 2 or 3, wherein the temperature of the atmospheric air stream is maintained at a constant value of approximately 700°C and the oxygen stream at ambient temperature.
6. Process according to claim 1, 2 or 3, wherein methane content is controlled at the outlet of a reforming section in order to obtain 0.2 to 3% by volume.
7. Process according to claim 1, 2 or 3, wherein methane content is controlled at the outlet of a reforming section to obtain 1.3% by volume.
8. Process according to claim 1, 2 or 3, wherein the H2/N2 ratio in a synthesis gas is set to 2.1 - 2.9.
9. Process according to claim 1, 2 or 3, wherein fuel gas is fed to a partial oxidation section of a reforming stage.
10. Process according to claim 1, 2 or 3, wherein the H2O/C ratio of all streams fed to a reformer is maintained at a value of < 2.75, further steam being added to the gas stream flowing from a reforming section.
11. Process according to claim 1, 2 or 3, wherein the amount of N2 fed to a reformer is smaller than the quantity required stoichiometrically for NH3 formation in synthesis gas, an oxygen-bearing nitrogen stream being added in a selective CO oxidation section upstream of CO separation in order to adjust the required H2/N2 ratio.
12. Process according to claim 1, 2 or 3, wherein the amount of N2 fed to a reformer is larger than the quantity required stoichiometrically for NH3 formation in synthesis gas, the required H2/N2 ratio being adjusted in a low-temperature purification section.
13. Process according to claim 1, 2 or 3, wherein the NH3 from a synthesis loop gas is at least partly absorbed with water and the loop gas is subsequently dried.
14. Process according to claim 1, 2 or 3, wherein NH3 from a synthesis loop gas is at least partially absorbed with water and the loop gas is subsequently dried, said NH3 being desorbed by process waste heat or a hot process gas stream.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19873719780 DE3719780A1 (en) | 1987-06-13 | 1987-06-13 | METHOD FOR PRODUCING AMMONIA FROM NATURAL GAS |
| DEP3719780.0 | 1987-06-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1334784C true CA1334784C (en) | 1995-03-21 |
Family
ID=6329637
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000569167A Expired - Fee Related CA1334784C (en) | 1987-06-13 | 1988-06-10 | Process for the production of ammonia from natural gas |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0300151B2 (en) |
| JP (1) | JP2515854B2 (en) |
| CN (1) | CN1017234B (en) |
| CA (1) | CA1334784C (en) |
| DE (2) | DE3719780A1 (en) |
| DK (1) | DK311488A (en) |
| ES (1) | ES2018063T5 (en) |
| ZA (1) | ZA884036B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE1004477A4 (en) * | 1990-06-26 | 1992-12-01 | Catalysts & Chem Europ | New method for producing synthesis gas for the manufacture of ammonia. |
| CN106807383B (en) * | 2017-02-10 | 2019-03-22 | 西北大学 | A method of preparing catalyst of ammonia and preparation method thereof and the catalyst preparation ammonia |
Family Cites Families (19)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1031285B (en) * | 1957-03-06 | 1958-06-04 | Basf Ag | Process for the extensive separation of the reaction product when performing chemical processes |
| US3081268A (en) * | 1961-02-07 | 1963-03-12 | Jr Walton H Marshall | Ammonia synthesis gas process |
| DE1233372B (en) * | 1964-05-15 | 1967-02-02 | Still Fa Carl | Process for the production of ammonia synthesis gas from gasification and degassing gases from coal |
| IT736029A (en) * | 1964-08-07 | |||
| DE2104384A1 (en) * | 1971-01-30 | 1972-08-24 | Metallgesellschaft Ag, 6000 Frankfurt | Two stage hydrocarbon cracking - for ammonia synthesis |
| DE2412841C2 (en) * | 1974-03-18 | 1982-11-11 | Metallgesellschaft Ag, 6000 Frankfurt | Reactor for splitting hydrocarbons on an indirectly heated catalyst |
| DE2862117D1 (en) * | 1977-08-22 | 1983-01-13 | Ici Plc | Ammonia production process |
| DE2860300D1 (en) * | 1977-08-26 | 1981-02-19 | Ici Plc | Ammonia synthesis and a plant for carrying out this synthesis |
| US4238468A (en) * | 1978-08-30 | 1980-12-09 | Engelhard Minerals And Chemicals Corporation | Ammonia manufacturing process |
| EP0093502B2 (en) * | 1982-04-14 | 1988-11-17 | Imperial Chemical Industries Plc | Ammonia production process |
| US4479925A (en) * | 1982-09-13 | 1984-10-30 | The M. W. Kellogg Company | Preparation of ammonia synthesis gas |
| DE3244252A1 (en) * | 1982-11-30 | 1984-05-30 | Uhde Gmbh, 4600 Dortmund | METHOD AND DEVICE FOR GENERATING PRODUCT GAS WITH HYDROGEN AND CARBON OXYDE CONTENT |
| CA1229467A (en) * | 1983-11-10 | 1987-11-24 | Exxon Research And Engineering Company | Low severity hydrocarbon steam reforming process |
| US4666680A (en) * | 1984-01-30 | 1987-05-19 | Fluor Corporation | Autothermal production of synthesis gas |
| GB8520892D0 (en) * | 1985-08-21 | 1985-09-25 | Ici Plc | Ammonia synthesis gas |
| EP0157480B1 (en) * | 1984-03-02 | 1989-07-26 | Imperial Chemical Industries Plc | Process for producing ammonia synthesis gas |
| EP0214991A1 (en) * | 1984-06-30 | 1987-03-25 | Stamicarbon B.V. | Process for preparing ammonia |
| DE3679090D1 (en) * | 1985-03-08 | 1991-06-13 | Ici Plc | SYNTHESIS GAS. |
| DE3532413A1 (en) * | 1985-09-11 | 1987-03-12 | Uhde Gmbh | DEVICE FOR GENERATING SYNTHESIS GAS |
-
1987
- 1987-06-13 DE DE19873719780 patent/DE3719780A1/en not_active Withdrawn
-
1988
- 1988-05-09 ES ES88107419T patent/ES2018063T5/en not_active Expired - Lifetime
- 1988-05-09 EP EP88107419A patent/EP0300151B2/en not_active Expired - Lifetime
- 1988-05-09 DE DE8888107419T patent/DE3860436D1/en not_active Expired - Fee Related
- 1988-06-07 ZA ZA884036A patent/ZA884036B/en unknown
- 1988-06-08 DK DK311488A patent/DK311488A/en not_active Application Discontinuation
- 1988-06-10 CA CA000569167A patent/CA1334784C/en not_active Expired - Fee Related
- 1988-06-10 JP JP63141947A patent/JP2515854B2/en not_active Expired - Lifetime
- 1988-06-13 CN CN88103626A patent/CN1017234B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DK311488A (en) | 1988-12-14 |
| ES2018063T5 (en) | 1995-08-16 |
| EP0300151B1 (en) | 1990-08-08 |
| ES2018063B3 (en) | 1991-03-16 |
| EP0300151B2 (en) | 1994-05-04 |
| CN1030063A (en) | 1989-01-04 |
| DE3860436D1 (en) | 1990-09-13 |
| DK311488D0 (en) | 1988-06-08 |
| ZA884036B (en) | 1989-03-29 |
| JPS63310718A (en) | 1988-12-19 |
| EP0300151A1 (en) | 1989-01-25 |
| CN1017234B (en) | 1992-07-01 |
| DE3719780A1 (en) | 1988-12-22 |
| JP2515854B2 (en) | 1996-07-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| AU2018221479B2 (en) | Process for the synthesis of ammonia with low emissions of CO2 in atmosphere | |
| JP2757977B2 (en) | Ammonia synthesis gas production method | |
| US4725380A (en) | Producing ammonia synthesis gas | |
| CA1210222A (en) | Ammonia production process | |
| CA3082075A1 (en) | Systems and methods for production and separation of hydrogen and carbon dioxide | |
| US20080272340A1 (en) | Method for Producing Syngas with Low Carbon Dioxide Emission | |
| US11654414B2 (en) | Hydrogen reforming system | |
| NZ207683A (en) | The production of synthesis gas and methanol from the synthesis gas | |
| NZ227799A (en) | Process for the production of methanol | |
| US4383837A (en) | Efficient methane production with metal hydrides | |
| US4238468A (en) | Ammonia manufacturing process | |
| CA1254748A (en) | Producing ammonia synthesis gas | |
| CA1160844A (en) | Synthesis gas for ammonia production | |
| CA1334784C (en) | Process for the production of ammonia from natural gas | |
| CA1259495A (en) | Energy recovery | |
| WO2023153928A1 (en) | Hybrid ammonia decomposition system | |
| GB2160516A (en) | Ammonia plant re-vamp process | |
| AU2021286875B2 (en) | Method for the production of hydrogen | |
| RU2643542C1 (en) | Method of obtaining hydrogen from hydrocarbon feedstock | |
| JP2024524085A (en) | Recovery of renewable hydrogen product from ammonia decomposition process | |
| JPS6039050B2 (en) | Methanol manufacturing method | |
| GB2033882A (en) | Production of ammonia | |
| EP4421027A1 (en) | Method for producing ammonia with reduced emissions and system thereof | |
| EP4375235A2 (en) | Integration of hydrogen fueled gas turbine with a hydrocarbon reforming process | |
| CN117545717A (en) | System and method for recovering inert gas from ammonia synthesis loop |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |