GB2034293A - Recovery of Ammonia - Google Patents
Recovery of Ammonia Download PDFInfo
- Publication number
- GB2034293A GB2034293A GB7936522A GB7936522A GB2034293A GB 2034293 A GB2034293 A GB 2034293A GB 7936522 A GB7936522 A GB 7936522A GB 7936522 A GB7936522 A GB 7936522A GB 2034293 A GB2034293 A GB 2034293A
- Authority
- GB
- United Kingdom
- Prior art keywords
- range
- surface area
- process according
- ammonia
- weight
- 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.)
- Granted
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- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 56
- 229910021529 ammonia Inorganic materials 0.000 title claims abstract description 27
- 238000011084 recovery Methods 0.000 title description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 26
- 238000000034 method Methods 0.000 claims abstract description 22
- 239000003054 catalyst Substances 0.000 claims abstract description 20
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 15
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 14
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000001257 hydrogen Substances 0.000 claims abstract description 13
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 13
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 13
- 239000006096 absorbing agent Substances 0.000 claims abstract description 12
- 229910052723 transition metal Inorganic materials 0.000 claims abstract description 10
- 150000003624 transition metals Chemical class 0.000 claims abstract description 10
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 8
- 239000010439 graphite Substances 0.000 claims abstract description 8
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 6
- 238000004519 manufacturing process Methods 0.000 claims abstract description 6
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000007795 chemical reaction product Substances 0.000 claims abstract description 4
- 229910052707 ruthenium Inorganic materials 0.000 claims abstract description 4
- 238000005406 washing Methods 0.000 claims abstract description 4
- 230000000737 periodic effect Effects 0.000 claims description 11
- 229910021645 metal ion Inorganic materials 0.000 claims description 7
- 238000006243 chemical reaction Methods 0.000 claims description 5
- 229910052768 actinide Inorganic materials 0.000 claims description 3
- 150000001255 actinides Chemical class 0.000 claims description 3
- 229910052747 lanthanoid Inorganic materials 0.000 claims description 3
- 150000002602 lanthanoids Chemical class 0.000 claims description 3
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 claims description 2
- 238000004064 recycling Methods 0.000 claims description 2
- 229910001414 potassium ion Inorganic materials 0.000 claims 1
- IGLNJRXAVVLDKE-UHFFFAOYSA-N rubidium atom Chemical compound [Rb] IGLNJRXAVVLDKE-UHFFFAOYSA-N 0.000 claims 1
- 229910001419 rubidium ion Inorganic materials 0.000 claims 1
- 229910052783 alkali metal Inorganic materials 0.000 abstract description 6
- 150000001340 alkali metals Chemical class 0.000 abstract description 6
- -1 ruthenium Chemical class 0.000 abstract description 2
- 229910052751 metal Inorganic materials 0.000 abstract 1
- 239000002184 metal Substances 0.000 abstract 1
- 230000015572 biosynthetic process Effects 0.000 description 3
- 238000003786 synthesis reaction Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000002808 molecular sieve Substances 0.000 description 2
- URGAHOPLAPQHLN-UHFFFAOYSA-N sodium aluminosilicate Chemical compound [Na+].[Al+3].[O-][Si]([O-])=O.[O-][Si]([O-])=O URGAHOPLAPQHLN-UHFFFAOYSA-N 0.000 description 2
- 150000003623 transition metal compounds Chemical class 0.000 description 2
- 238000009620 Haber process Methods 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 description 1
- 150000001540 azides Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 238000011065 in-situ storage Methods 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 235000013980 iron oxide Nutrition 0.000 description 1
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 1
- 239000012263 liquid product Substances 0.000 description 1
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 238000005057 refrigeration Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
- B01J21/18—Carbon
-
- 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
- C01C1/0411—Preparation of ammonia by synthesis in the gas phase from N2 and H2 in presence of a catalyst characterised by the 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
- C01C1/0458—Separation of NH3
- C01C1/0464—Separation of NH3 by absorption in liquids, e.g. water
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J35/00—Catalysts, in general, characterised by their form or physical properties
- B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
- B01J35/61—Surface area
- B01J35/615—100-500 m2/g
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Analytical Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Catalysts (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
A process for the production of ammonia comprises passing hydrogen and nitrogen over a catalyst disclosed in 45711/76 comprising a specified transition metal, e.g., ruthenium, and a modifying metal, e.g., an alkali metal, supported on a graphite-containing carbon support having specified surface area properties, the ammonia being recovered by washing the reaction product with water in an absorber to dissolve the ammonia produced.
Description
SPECIFICATION
Process for the Production of Ammonia
This invention relates to a process for the production of ammonia.
With increased pressure on the world's food resources the demand for nitrogen-containing fertilisers based on ammonia has grown rapidly in recent years. Current Haber processes using nitrogen
and hydrogen as feedstock generally use a potassium promoted iron catalyst, usually with other
promoters such as alumina. These catalysts are reduced in situ from bulk iron oxides before use and operate under severe conditions, e.g., pressures of up to 300 bars and temperatures of 4500--5000C.
The reaction N2+3H2=2NH3 is highly exothermic and thus the equilibrium is moved to the right at lower temperatures. However, present day commercial catalysts are not sufficiently active at lower temperatures to enable the reaction to reach equilibrium within the short time the reactants are in contact with the catalyst. Activity increases with temperature and therefore a compromise has to be
reached.
Recent work by Aika et al, Journal of Catalysis, 27, 424-431(1972), on the synthesis of ammonia discloses that synthesis over a ruthenium catalyst is promoted by the addition of an alkali metal, particularly when the ruthenium is supported by active carbon or alumina.
Similarly, British Patent Specification 1 367112 to to Sagami Chemical Research Centre discloses a complex catalyst for ammonia synthesis which comprises (a) at least one alkali metal belonging to
Group 1 A of the Periodic Table, (b) at least one compound, preferably a halide, oxide or sulphide, of transition metal selected from the group consisting of Group 4B, Group 5B, Group 6B, Group 7B and
Group 8 of the Periodic Table and graphite. The Periodic Table referred to by Sagami is that given in the "Handbook of Chemistry", edited by Norbert Adolf Lange; McGraw-Hill, 1961; pages 56 to 57.
The complex comprises an alkali metal as the electron donor, graphite as the electron acceptor and a transition metal compound. The alkali metal and the transition metal compound are present as intercalates in the graphite lattice. Aika and Sagami both disclose the use of free alkali metal or precursors thereof, such as azides, as electron donors.
Our copending British Patent Application No. 45711/76 discloses a catalyst comprising (i) as support a graphite-containing carbon having (a) a basal plane surface area of at least 100 m2/g. (b) a ratio of BET surface area to basal plane surface area of not more than 8:1, preferably not more than 5:1 and (c) a ratio of basal plane surface area to edge surface area of at least 2:1 and preferably at least 5::1 and (ii) as active component (a) 0.1 to 50%, preferably 130%, most preferably 510%, by weight of a transition metal of the 4th, 5th and 6th horizontal Periods of Groups VB, VIB, VIIB and VIII of the
Periodic Table expressed as % by weight of total catalyst and (b) 0.1 to 4 times by weight of (a) of a modifying metal ion selected from Groups IA or IIA of the Periodic Table or the lanthanides or actinides, the modifying metal ion being actively associated with the transition metal rather than the support.
Unless otherwise indicated the Periodic Table referred to in the present specification is the
Periodic Table published on page B-4 of the Handbook of Chemistry and Physics, 57th Edition, 1 976- 1977, published by CRC Press, Cleveland, Ohio.
Such a catalyst is suitable for the production of ammonia from hydrogen and nitrogen.
It is distinguished from the prior art in that it is neither an electron donor-acceptor complex nor is it an intercalate compound.
Ammonia is at present recovered cryogenically from current processes and the cost of refrigeration represents a considerable proportion of total cost. Furthermore, recovery by this method is incomplete since a proportion of the ammonia remains in the vapour form arid is recycled together with unconverted hydrogen and nitrogen. This, of course, reduces the conversion per pass of the reactor.
We have now discovered that because of the relatively high tolerance of the catalyst described in
British Patent Application No. 45711/76 to water, ammonia can be recovered economically by washing the reaction product with water.
Thus according to the present invention there is provided a process for the production of ammonia which process comprises passing a feedstock containing hydrogen and nitrogen over a catalyst comprising (i) as support a graphite-containing carbon having (a) a basal plane surface area of at least 100 m2/g, (b) a ratio of BET surface area to basal plane surface area of not more than 8:1, preferably not more than 5:1, and (c) a ratio of basal plane surface area to edge surface area of at least 2:1 and preferably, at least 5::1, and (ii) as active component (a) 0.1 to 50% preferably 130%, most preferably 510%, by weight of a transition metal of the 4th, 5th and 6th horizontal Periods of Groups
VB, VIB, VIIB and VIII of the Periodic Table, expressed as % by weight of total catalyst, and (b) 0.1 to 4 times by weight of (a) of a modifying metal ion selected from Groups IA or IIA of the Periodic Table or the lanthanides or actinides, the modifying metal ion being actively associated with the transition metal rather than the support, under conditions of temperature, pressure and space velocity such that conversion to ammonia is effected, washing the reaction product with water in an absorber to dissolve the ammonia produced, separating aqueous ammonia from unreacted hydrogen and nitrogen and recycling the unreacted hydrogen and nitrogen to the reactor.
Broad and preferred ranges of process conditions are as follows:- Broad Range Preferred Range
Temperature OC 250-600 300-500 Pressure bars Atmospheric-300 20--1 30 Space velocity v/v/hr 1,000-100,000 5,000--30,000 The ammonia is produced in the form of a concentrated solution from which the water may be removed if desired, e.g., in a stripper.
The unconverted hydrogen and nitrogen separated after the water wash are substantially saturated with water vapour. As stated previously, the catalyst has a relatively high tolerance to water vapour but, even so, it may be desirable to remove some of the water vapour from the recycled gases.
This may be done by conventional methods such as drying over a molecular sieve.
It is not, however, necessary to dry the gases as thoroughly as would be the case if they were to be recycled to a process employing a conventional catalyst.
The absorber may be operated under the following conditions provided that there is a minimum ammonia concentration at the absorber inlet of 5% by weight.
Broad Range Preferred Range
Pressure bars Atmospheric-300 20-130 Temperature OC 5-55 15 vi 5 Conditions in the stripper are not critical. However, the pressure may be in the range 10-30 bar and the temperature in the range 500--1500C.
The invention is illustrated with reference to the accompanying drawing which is a flow diagram.
Products from a reactor containing ammonia, unreacted nitrogen and hydrogen are supplied by line 1 to absorber 2 in which they are contacted with water supplied by line 3.
In the absorber, ammonia dissolves in the water and the resulting aqueous solution of ammonia is removed by line 4, heated in heat exchanger 5 and passed to a stripper 6. Unreacted nitrogen and hydrogen do not dissolve in the water in the absorber 2 and are removed by line 7 and passed to a molecular sieve drier (not shown) before being recycled to the reactor (not shown).
In the stripper 6, gaseous ammonia is stripped from the aqueous solution and removed from the stripper by line 8. It then passes through a cooler 9 and leaves through line 10 as a gaseous or liquid product. Stripped solvent, i.e., water, leaves the base of the stripper by line 11, passes through heat exchanger 5 where it gives up heat to the feed to the stripper and returns to the absorber by line 3.
Claims (12)
1. A process for the production of ammonia which process comprises passing a feedstock containing hydrogen and nitrogen over a catalyst comprising (i) as support a graphite-containing carbon having (a) a basal plane surface area of at least 100 m2/g, (b) a ratio of BET surface area to basal plane surface area of not more than 8:1, and (c) a ratio of basal plane surface area to edge surface area of at least 2::1 and (ii) as active component (a) 0.1 to 50% by weight of a transition metal of the 4th, 5th and 6th horizontal Periods of Groups VB, VIIB and VIII of the Periodic Table, expressed as % by weight of total catalyst, and (b) 0.1 to 4 times by weight of (a) of a modifying metal ion selected from Groups IA or IIA of the Periodic Table or the lanthanides or actinides, the modifying metal ion being actively associated with the transition metal rather than the support, under conditions of temperature, pressure and space velocity such that conversion to ammonia is effected, washing the reaction product with water in an absorber to dissolve the ammonia produced, separating aqueous ammonia from unreacted hydrogen and nitrogen and recycling the unreacted hydrogen and nitrogen to the reactor.
2. A process according to Claim 1 wherein the graphite-containing carbon has a ratio of BET surface area to basal plane surface area of not more than 5:1 and a ratio of basal plane surface area to edge surface area of at least 5:1.
3. A process according to either of Claims 1 or 2 wherein the transition metal is present in amount 1 to 30% by weight expressed as % by weight of total catalyst.
4. A process according to any of the preceding claims wherein the transition metal is ruthenium.
5. A process according to any of the preceding claims wherein the modifying metal ions are rubidium or potassium ions.
6. A process according to any of the preceding claims wherein the feedstock is passed over the catalyst at a temperature in the range 2500 to 6000C, a pressure in the range atmospheric to 300 bars and a space velocity in the range 1,000 to 100,000 v/v/hr.
7. A process according to Claim 6 wherein the feedstockis passed over the catalyst at a temperature in the range 3000 to 5000C, a pressure in the range 20 to 200 bars and a space velocity in the range 5,000 to 30,000 v/v/hr.
8. A process according to any of the preceding claims wherein the wash water supplied to the absorber inlet contains a minimum ammonia concentration of 5% by weight and the absorber is operated under a pressure in the range atmospheric to 300 bar and a temperature in the range 50 to 550C.
9. A process according to Claim 8 wherein the absorber is operated under a pressure in the range 20 to 300 bar and a temperature in the range 1 50 to 450C.
1 0. A process according to any of the preceding claims wherein the stripper is operated under a pressure in the range 10 to 30 bar and a temperature in the range 50 to 1 500C.
11. A process as hereinbefore described with reference to the accompanying drawing.
12. Ammonia whenever prepared by a process according to any of the preceding claims.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7936522A GB2034293B (en) | 1978-10-25 | 1979-10-22 | Recovery of ammonia |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB7841923 | 1978-10-25 | ||
| GB7936522A GB2034293B (en) | 1978-10-25 | 1979-10-22 | Recovery of ammonia |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2034293A true GB2034293A (en) | 1980-06-04 |
| GB2034293B GB2034293B (en) | 1982-10-27 |
Family
ID=26269323
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7936522A Expired GB2034293B (en) | 1978-10-25 | 1979-10-22 | Recovery of ammonia |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2034293B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0058531A1 (en) * | 1981-02-13 | 1982-08-25 | The British Petroleum Company p.l.c. | Process for the production of ammonia |
-
1979
- 1979-10-22 GB GB7936522A patent/GB2034293B/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0058531A1 (en) * | 1981-02-13 | 1982-08-25 | The British Petroleum Company p.l.c. | Process for the production of ammonia |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2034293B (en) | 1982-10-27 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |