NZ760482B2 - Method for improving efficiency of an ammonia synthesis gas plant - Google Patents
Method for improving efficiency of an ammonia synthesis gas plant Download PDFInfo
- Publication number
- NZ760482B2 NZ760482B2 NZ760482A NZ76048218A NZ760482B2 NZ 760482 B2 NZ760482 B2 NZ 760482B2 NZ 760482 A NZ760482 A NZ 760482A NZ 76048218 A NZ76048218 A NZ 76048218A NZ 760482 B2 NZ760482 B2 NZ 760482B2
- Authority
- NZ
- New Zealand
- Prior art keywords
- gas
- electrolysis
- synthesis gas
- unit
- oxygen
- Prior art date
Links
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 74
- 229910021529 ammonia Inorganic materials 0.000 title claims abstract description 37
- 230000015572 biosynthetic process Effects 0.000 title claims abstract description 36
- 238000003786 synthesis reaction Methods 0.000 title claims abstract description 36
- 238000000034 method Methods 0.000 title claims abstract description 23
- 239000007789 gas Substances 0.000 claims abstract description 60
- 238000005868 electrolysis reaction Methods 0.000 claims abstract description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 21
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 16
- 239000001301 oxygen Substances 0.000 claims abstract description 16
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 16
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 13
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910001882 dioxygen Inorganic materials 0.000 claims abstract description 9
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 32
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 16
- 239000001569 carbon dioxide Substances 0.000 claims description 10
- 239000001257 hydrogen Substances 0.000 claims description 8
- 229910052739 hydrogen Inorganic materials 0.000 claims description 8
- 238000011144 upstream manufacturing Methods 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 12
- 238000000629 steam reforming Methods 0.000 abstract description 11
- 239000000446 fuel Substances 0.000 abstract description 8
- 229930195733 hydrocarbon Natural products 0.000 abstract description 8
- 150000002430 hydrocarbons Chemical class 0.000 abstract description 8
- 239000004215 Carbon black (E152) Substances 0.000 abstract description 7
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 abstract description 7
- 239000003546 flue gas Substances 0.000 abstract description 3
- 238000010438 heat treatment Methods 0.000 abstract description 2
- 229960000510 ammonia Drugs 0.000 description 27
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 8
- 238000002407 reforming Methods 0.000 description 6
- 229910002091 carbon monoxide Inorganic materials 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 238000002360 preparation method Methods 0.000 description 4
- 238000000926 separation method Methods 0.000 description 4
- 150000002500 ions Chemical class 0.000 description 3
- 239000003345 natural gas Substances 0.000 description 3
- 238000010025 steaming Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- PPNXXZIBFHTHDM-UHFFFAOYSA-N aluminium phosphide Chemical compound P#[Al] PPNXXZIBFHTHDM-UHFFFAOYSA-N 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 208000028659 discharge Diseases 0.000 description 1
- 238000011143 downstream manufacturing Methods 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 238000006057 reforming reaction Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/02—Processes for making hydrogen or synthesis gas
- C01B2203/0205—Processes for making hydrogen or synthesis gas containing a reforming step
- C01B2203/0227—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step
- C01B2203/0233—Processes for making hydrogen or synthesis gas containing a reforming step containing a catalytic reforming step the reforming step being a steam reforming step
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/02—Processes for making hydrogen or synthesis gas
- C01B2203/0283—Processes for making hydrogen or synthesis gas containing a CO-shift step, i.e. a water gas shift step
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
- C01B2203/0435—Catalytic purification
- C01B2203/0445—Selective methanation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
- C01B2203/0455—Purification by non-catalytic desulfurisation
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/04—Integrated processes for the production of hydrogen or synthesis gas containing a purification step for the hydrogen or the synthesis gas
- C01B2203/0465—Composition of the impurity
- C01B2203/0475—Composition of the impurity the impurity being carbon dioxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/06—Integration with other chemical processes
- C01B2203/068—Ammonia synthesis
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/08—Methods of heating or cooling
- C01B2203/0805—Methods of heating the process for making hydrogen or synthesis gas
- C01B2203/0811—Methods of heating the process for making hydrogen or synthesis gas by combustion of fuel
- C01B2203/0816—Heating by flames
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/14—Details of the flowsheet
- C01B2203/141—At least two reforming, decomposition or partial oxidation steps in parallel
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B2203/00—Integrated processes for the production of hydrogen or synthesis gas
- C01B2203/14—Details of the flowsheet
- C01B2203/146—At least two purification steps in series
-
- 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
-
- 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
- C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
- C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
- C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
- C01B3/382—Multi-step processes
-
- 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
- C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
- C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
- C01B3/38—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts
- C01B3/384—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents using catalysts the catalyst being continuously externally heated
-
- 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
- C01B3/32—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air
- C01B3/34—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents
- C01B3/48—Production of hydrogen or of gaseous mixtures containing a substantial proportion of hydrogen by reaction of gaseous or liquid organic compounds with gasifying agents, e.g. water, carbon dioxide, air by reaction of hydrocarbons with gasifying agents followed by reaction of water vapour with carbon monoxide
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/04—Preparation of ammonia by synthesis in the gas phase
- C01C1/0405—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/04—Preparation of ammonia by synthesis in the gas phase
- C01C1/0405—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst
- C01C1/0417—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst characterised by the synthesis reactor, e.g. arrangement of catalyst beds and heat exchangers in the reactor
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
- C07C1/02—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon
- C07C1/12—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon from oxides of a carbon from carbon dioxide with hydrogen
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B1/00—Electrolytic production of inorganic compounds or non-metals
- C25B1/01—Products
- C25B1/02—Hydrogen or oxygen
- C25B1/04—Hydrogen or oxygen by electrolysis of water
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
- C25B15/00—Operating or servicing cells
- C25B15/08—Supplying or removing reactants or electrolytes; Regeneration of electrolytes
-
- 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
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/30—Hydrogen technology
- Y02E60/36—Hydrogen production from non-carbon containing sources, e.g. by water electrolysis
-
- 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
- Y02P20/133—Renewable energy sources, e.g. sunlight
-
- 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
- Y02P20/50—Improvements relating to the production of bulk chemicals
- Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts
Abstract
Method for improving efficiency of an existing ammonia synthesis gas plant or a new ammonia synthesis gas plant by establishing a combination of secondary steam reforming using oxygen from electrolysis of water for the production of ammonia synthesis gas. The method comprises the steps of a) establishing an electrolysis unit and preparing a separate hydrogen gas containing stream and a separate oxygen gas containing stream by electrolysis of water; (b) establishing a gas pipe for transporting the separate hydrogen gas containing stream from the electrolysis unit to the synthesis gas compressor and/or to the methanation step; and (c) establishing a gas pipe for transporting at least part of the separate oxygen gas stream from the electrolysis unit to a burner in the secondary reformer. The disadvantage of existing method involve a relatively high hydrocarbon feed stock and fuel consumption for use in heating the endothermic primary steam reforming in the fired primary steam reformer and consequently a large CO2 emission in the flue gas from burners used to heat the reformer. The method allows for lower fuel consumption and a significantly longer equipment lifespan.
Description
Title: Method for improving efficiency of an ammonia synthesis gas plant The present application is directed to the preparation of ammonia synthesis gas. More particular, the invention is a method for improving efficiency of a conventional ammonia synthesis gas plant by combining electrolysis of water and the conventional primary and secondary steam reforming of a hydrocarbon feed stock for the preparation of hydrogen and nitrogen containing ammonia synthesis gas.
Ammonia synthesis gas is conventionally prepared by subjecting arbon feed lly natural gas and/or higher arbons to endothermic steam reforming reac- tions in a fired tubular primary steam reformer by contact with a steam reforming st. The primary reformed gas is then fed into a secondary adiabatic steam reformer, wherein part of hydrogen formed in the primary steam ing and residual s of hydrocarbons in the gas from the primary steam ing are partial ed with air and steam and subsequently reformed in presence of a secondary reforming catalyst. From the secondary reformer, raw synthesis gas is withdrawn containing hydrogen, carbon monoxide and carbon dioxide formed during reaction of the feedstock in the above steam reforming reactions and nitrogen introduced into the gas through addition of air in the secondary reforming step.
The disadvantage of the primary and secondary reforming process is a relatively high hydrocarbon feed stock and fuel consumption for use in heating the endothermic primary steam reforming in the fired primary steam reformer and 55_1 (GHMatters) P45738NZ00 consequently a large CO2 emission in the flue gas from burners used to heat the reformer. The CO2 product can be captured from the s and used for downstream processes such as urea production or enhanced oil recovery.
However, primary and secondary steam reforming is still frequently ed in the industry, particularly in existing reforming plants for the production of ammonia synthesis Secondary steam reforming comprises partial oxidation, using oxygen containing atmosphere, of a primary reformed feed gas to CO, CO2, H2, H2O and remaining hydrocarbon and subsequently steam ing of the arbon to form raw synthesis gas.
Recently, a combination of electrolysis of water for production of hydrogen and air separation for the production of nitrogen has been envisaged for the preparation of ammo- nia synthesis gas, at least in patent ture. The thus produced hydrogen and nitrogen are ed in stoichiometric ratios to form synthesis gas for ammonia production.
The disadvantage of the combination of electrolysis and air separation is, however, that oxygen is produced as by-prod- uct in both electrolysis and air separation, which has no use in the ammonia synthesis, and can be considered as energy loss.
Typically, existing industrial ammonia synthesis gas plants, the so-called front end of an ammonia plant se as already mentioned above, a fired primary steam re- 20147755_1 (GHMatters) P45738NZ00 former, a secondary steam reformer with a burner at gas inlet side and a steam reforming catalyst bed at gas outlet side. The burner is typically operated with air.
The raw ammonia synthesis gas withdrawn from the secondary steam reformer is uently treated in a water gas shift unit for the production of further hydrogen and conversion of carbon monoxide to carbon dioxide by the known water gas shift reaction.
The carbon dioxide contained in the shifted ammonia sis gas is then removed in a carbon dioxide removal process.
Remaining amounts of carbon dioxide and/or carbon monoxide in the ammonia synthesis gas from the carbon dioxide removal process are removed by ation in a chemical reaction that converts carbon monoxide and/or carbon e to methane.
The thus prepared ammonia synthesis gas is introduced into an ammonia make up gas compressor and sent into the ammonia production unit.
The present invention is based on establishing a combination of the fired primary steam reforming process and the ary ing process using air or oxygen enriched air in the ion of the secondary reformer burner and a new implemented step of electrolysis of water for the pro- duction of ammonia synthesis gas. 20147755_1 (GHMatters) P45738NZ00 Thus, this invention provides method of improving ency of an ammonia synthesis gas plant, the ammonia synthesis gas plant comprises a fired primary steam er and a secondary steam reformer operated with an oxygen con- taining atmosphere, a water gas shift unit, a carbon dioxide removal unit, a methanation step and an ammonia sis gas compressor, the method comprises the steps of (a) establishing an electrolysis unit and preparing a sepa- rate hydrogen gas containing stream and a separate oxygen gas containing stream by electrolysis of water; (b) establishing a gas pipe for transporting the separate hydrogen gas containing stream from the electrolysis unit to the synthesis gas compressor and/or to the methanation step; and (c) establishing a gas pipe for transporting at least part of the separate oxygen gas stream from the electrolysis unit to a burner in the ary reformer.
The method of the ion can be used to improve efficiency of an existing ammonia synthesis gas plant operated with y and secondary ing or in a new plant with primary and secondary reforming. The improvement of an existing or a new ammonia synthesis gas plant by the method of the invention aims to increase the production capacity of the plant and/or to save fuel in the fired primary steam reformer at a fixed capacity, as oxygen from water elec- trolysis provides heat for the reforming reaction in the secondary reformer. y, the duty of the primary reformer is decreased, when the oxygen content in the oxygen 20147755_1 (GHMatters) P45738NZ00 containing atmosphere in the secondary reformer is sed with the oxygen prepared in the water electrolysis.
As a result, the hydrocarbon slip in the gas from the primary reformer increases and the gas exit temperature de- creases, which again results in lower fuel consumption for firing the primary reformer. Due to the lower fuel ption , the reformer tube wall temperature is reduced, resulting in a significantly longer tube life time.
Another advantage is that the l hydrocarbon slip outlet the secondary reformer can be the same as in conventional plants t electrolysis or can be reduced to obtain improved synthesis gas composition because of reduced content of inerts resulting in reduced purge from the ammo- nia loop and thus a more efficient utilization of the feed stock.
The method according to the invention provides further advantage of less emission of CO2 from the primary flue gas stack.
Still an advantage is that the CO2 partial pressure is increased at inlet to the carbon dioxide removal unit, which improves the carbon e removal efficiency by reducing the required energy consumption.
Compared to prior art s using electrolysis of water for en production and air separation for nitrogen production, the oxygen product from electrolysis of water is advantageously used for partial oxidation in secondary 20147755_1 (GHMatters) P45738NZ00 reformer resulting in a reduced size of the primary reformer in a new plant or reduced load in an existing plant, which is a costly and an energy ive unit and s.
Still an age of the invention is that energy for operating the electrolysis unit can be renewable energy generated by lls, solar cells, hydraulic energy or other renewables.
Thus, in a preferred embodiment of the ion, the electrolysis unit is powered by renewable energy.
Preferably, the electrolysis of water is performed at elevated pressure according to process air compressor dis- charge pressure, which delivers the prepared stream of oxygen at elevated pressure to the burner of the secondary reformer and the hydrogen stream to the synthesis gas compressor and/or to the methanation step.
Thus, in a preferred embodiment of the invention, the electrolysis unit is pressurized.
The synergy in combining water electrolysis with secondary ing technology for ammonia sis gas tion, results in overall savings of hydrocarbon feedstock and fuel for the reforming process.
In Table 1 below, key figures of ammonia synthesis gas preparation are given for a 2200 MTPD ammonia plant for comparison of conventional syngas technologies and conventional syngas technology combined with water electrolysis. 20147755_1 (GHMatters) P45738NZ00 Technology Natural gas Natural gas Power for CO2 in flue Primary Tout for syngas feed con- fuel con- oly- gas, Nm3/h reformer Primary Repreparation sumption, sumption, sis, MW duty, Gcal/h former, oC Nm3/h Nm3/h Conventional 57,408 19,273 0 21,899 108.82 807 Conventional 57,108 14,072 54 16,438 82.34 748 with water 7 electrolysis (25% oxygen in air) Table 1 20147755_1 (GHMatters) P45738NZ00
Claims (5)
1. A method of improving efficiency of an ammonia synthesis gas plant, the ammonia synthesis gas plant comprising a 5 fired primary steam reformer and a secondary steam reformer operated with an oxygen containing atmosphere, a water gas shift unit, a carbon dioxide l unit, a methanation step and an ammonia synthesis gas compressor, the method comprising the steps of (a) establishing an olysis unit and preparing a separate en gas containing stream and a separate oxygen gas containing stream by electrolysis of water; 15 (b) ishing a gas pipe for transporting the separate hydrogen gas containing stream from the electrolysis unit to the synthesis gas compressor and/or to the methanation step; and 20 (c) establishing a gas pipe for transporting at least part of the separate oxygen gas stream from the electrolysis unit to a burner in the secondary reformer.
2. The method according to claim 1, wherein the electrol- 25 ysis unit is powered by renewable energy.
3. The method according to claim 1 or 2, wherein the oxygen containing here, is air enriched with oxygen from the separate oxygen gas stream. 20147755_1 (GHMatters) P45738NZ00
4. The method according to any one of claims 1 to 3, wherein the electrolysis unit is pressurized.
5. Improved ammonia synthesis gas plant comprising a 5 fired primary steam reformer and a secondary steam reformer operated with an oxygen containing atmosphere, a water gas shift unit, a carbon dioxide removal unit, a ation reactor and an ammonia synthesis gas compressor, wherein the ammonia sis gas plant further comprises an elec- 10 trolysis unit providing a separate hydrogen ning stream and a te oxygen gas containing stream by electrolysis of water and a gas pipe for transporting the separate hydrogen gas containing stream from the electrolysis unit to the synthesis gas compressor and/or to the methana- 15 tion reactor and a gas pipe for orting at least part of the separate oxygen gas stream from the electrolysis unit upstream into a burner in the secondary reformer. 20147755_1 (GHMatters) P45738NZ00
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DKPA201700425 | 2017-07-25 | ||
DKPA201700522 | 2017-09-25 | ||
PCT/EP2018/068806 WO2019020377A1 (en) | 2017-07-25 | 2018-07-11 | Method for improving efficiency of an ammonia synthesis gas plant |
Publications (2)
Publication Number | Publication Date |
---|---|
NZ760482A NZ760482A (en) | 2023-10-27 |
NZ760482B2 true NZ760482B2 (en) | 2024-01-30 |
Family
ID=
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11840448B2 (en) | Method for the preparation of ammonia synthesis gas | |
KR102599470B1 (en) | Process for simultaneous production of methanol and ammonia | |
US11370658B2 (en) | Method for the preparation of ammonia synthesis gas | |
US20230257275A1 (en) | Method for improving efficiency of an ammonia synthesis gas plant | |
WO2023153928A1 (en) | Hybrid ammonia decomposition system | |
AU2021286875B2 (en) | Method for the production of hydrogen | |
CA3217663A1 (en) | Method for production of blue ammonia | |
NZ760482B2 (en) | Method for improving efficiency of an ammonia synthesis gas plant | |
EA040550B1 (en) | METHOD FOR INCREASING EFFICIENCY OF INSTALLATION FOR PRODUCING SYNTHESIS GAS FOR AMMONIA PRODUCTION | |
EA040478B1 (en) | METHOD FOR PRODUCING SYNTHESIS GAS FOR AMMONIA PRODUCTION |