CA2181337C - Material for removing contaminants from gaseous stream - Google Patents
Material for removing contaminants from gaseous stream Download PDFInfo
- Publication number
- CA2181337C CA2181337C CA002181337A CA2181337A CA2181337C CA 2181337 C CA2181337 C CA 2181337C CA 002181337 A CA002181337 A CA 002181337A CA 2181337 A CA2181337 A CA 2181337A CA 2181337 C CA2181337 C CA 2181337C
- Authority
- CA
- Canada
- Prior art keywords
- absorber
- catalyst
- specie
- surface area
- 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.)
- Expired - Lifetime
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- 239000000463 material Substances 0.000 title claims description 57
- 239000000356 contaminant Substances 0.000 title description 2
- 239000003054 catalyst Substances 0.000 claims abstract description 124
- 239000006096 absorbing agent Substances 0.000 claims abstract description 118
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims abstract description 39
- 239000007789 gas Substances 0.000 claims abstract description 38
- 238000000034 method Methods 0.000 claims abstract description 35
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 23
- 239000003344 environmental pollutant Substances 0.000 claims abstract description 23
- 231100000719 pollutant Toxicity 0.000 claims abstract description 23
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 18
- 150000005323 carbonate salts Chemical class 0.000 claims abstract 2
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 162
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 36
- 230000003647 oxidation Effects 0.000 claims description 36
- 238000007254 oxidation reaction Methods 0.000 claims description 36
- 229910002091 carbon monoxide Inorganic materials 0.000 claims description 35
- 241000894007 species Species 0.000 claims description 29
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 18
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 claims description 13
- 239000011248 coating agent Substances 0.000 claims description 13
- 238000000576 coating method Methods 0.000 claims description 13
- 229910000029 sodium carbonate Inorganic materials 0.000 claims description 13
- 239000000243 solution Substances 0.000 claims description 11
- XTQHKBHJIVJGKJ-UHFFFAOYSA-N sulfur monoxide Chemical class S=O XTQHKBHJIVJGKJ-UHFFFAOYSA-N 0.000 claims description 9
- 229910052815 sulfur oxide Inorganic materials 0.000 claims description 9
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims description 8
- -1 hydroxide compound Chemical class 0.000 claims description 8
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 claims description 8
- 239000011159 matrix material Substances 0.000 claims description 7
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 6
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 6
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims description 6
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 claims description 6
- 239000003513 alkali Substances 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 6
- 239000000919 ceramic Substances 0.000 claims description 5
- 238000002485 combustion reaction Methods 0.000 claims description 5
- 229910000027 potassium carbonate Inorganic materials 0.000 claims description 5
- 229920006395 saturated elastomer Polymers 0.000 claims description 5
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 4
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 4
- 230000003197 catalytic effect Effects 0.000 claims description 4
- 229910052703 rhodium Inorganic materials 0.000 claims description 4
- 239000010948 rhodium Substances 0.000 claims description 4
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 claims description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 3
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 3
- 238000001354 calcination Methods 0.000 claims description 3
- 229910017052 cobalt Inorganic materials 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- 239000010949 copper Substances 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 229910052750 molybdenum Inorganic materials 0.000 claims description 3
- 239000011733 molybdenum Substances 0.000 claims description 3
- 229910052759 nickel Inorganic materials 0.000 claims description 3
- 229910052763 palladium Inorganic materials 0.000 claims description 3
- 239000000377 silicon dioxide Substances 0.000 claims description 3
- 239000007864 aqueous solution Substances 0.000 claims description 2
- 150000004679 hydroxides Chemical class 0.000 claims description 2
- 239000007787 solid Substances 0.000 claims description 2
- 238000001035 drying Methods 0.000 claims 3
- 238000000151 deposition Methods 0.000 claims 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 claims 2
- 229910052700 potassium Inorganic materials 0.000 claims 2
- 239000011591 potassium Substances 0.000 claims 2
- 239000002904 solvent Substances 0.000 claims 2
- 229910052783 alkali metal Inorganic materials 0.000 claims 1
- 229910000288 alkali metal carbonate Inorganic materials 0.000 claims 1
- 150000008041 alkali metal carbonates Chemical class 0.000 claims 1
- 150000001340 alkali metals Chemical class 0.000 claims 1
- 229910010272 inorganic material Inorganic materials 0.000 claims 1
- 239000011147 inorganic material Substances 0.000 claims 1
- 229910052744 lithium Inorganic materials 0.000 claims 1
- 229910052708 sodium Inorganic materials 0.000 claims 1
- 239000011734 sodium Substances 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 7
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000002474 experimental method Methods 0.000 description 28
- RAHZWNYVWXNFOC-UHFFFAOYSA-N Sulphur dioxide Chemical compound O=S=O RAHZWNYVWXNFOC-UHFFFAOYSA-N 0.000 description 10
- JCXJVPUVTGWSNB-UHFFFAOYSA-N nitrogen dioxide Inorganic materials O=[N]=O JCXJVPUVTGWSNB-UHFFFAOYSA-N 0.000 description 9
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 8
- 230000001172 regenerating effect Effects 0.000 description 8
- 238000011069 regeneration method Methods 0.000 description 8
- 239000012530 fluid Substances 0.000 description 7
- 230000008929 regeneration Effects 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 229910002092 carbon dioxide Inorganic materials 0.000 description 6
- 239000000567 combustion gas Substances 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 5
- AKEJUJNQAAGONA-UHFFFAOYSA-N sulfur trioxide Chemical compound O=S(=O)=O AKEJUJNQAAGONA-UHFFFAOYSA-N 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- 238000006722 reduction reaction Methods 0.000 description 4
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 239000011324 bead Substances 0.000 description 3
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- 229910052717 sulfur Inorganic materials 0.000 description 3
- 239000011593 sulfur Substances 0.000 description 3
- MGWGWNFMUOTEHG-UHFFFAOYSA-N 4-(3,5-dimethylphenyl)-1,3-thiazol-2-amine Chemical compound CC1=CC(C)=CC(C=2N=C(N)SC=2)=C1 MGWGWNFMUOTEHG-UHFFFAOYSA-N 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 238000010531 catalytic reduction reaction Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000012153 distilled water Substances 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 229910052808 lithium carbonate Inorganic materials 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 230000007420 reactivation Effects 0.000 description 2
- 229910001220 stainless steel Inorganic materials 0.000 description 2
- 239000010935 stainless steel Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000011144 upstream manufacturing Methods 0.000 description 2
- OBETXYAYXDNJHR-UHFFFAOYSA-N 2-Ethylhexanoic acid Chemical compound CCCCC(CC)C(O)=O OBETXYAYXDNJHR-UHFFFAOYSA-N 0.000 description 1
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- ODUCDPQEXGNKDN-UHFFFAOYSA-N Nitrogen oxide(NO) Natural products O=N ODUCDPQEXGNKDN-UHFFFAOYSA-N 0.000 description 1
- 239000011149 active material Substances 0.000 description 1
- 239000000809 air pollutant Substances 0.000 description 1
- 231100001243 air pollutant Toxicity 0.000 description 1
- 230000003466 anti-cipated effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000010953 base metal Substances 0.000 description 1
- SHZIWNPUGXLXDT-UHFFFAOYSA-N caproic acid ethyl ester Natural products CCCCCC(=O)OCC SHZIWNPUGXLXDT-UHFFFAOYSA-N 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000003337 fertilizer Substances 0.000 description 1
- 239000003546 flue gas Substances 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 231100001261 hazardous Toxicity 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 1
- 229910000510 noble metal Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- VWDWKYIASSYTQR-UHFFFAOYSA-N sodium nitrate Inorganic materials [Na+].[O-][N+]([O-])=O VWDWKYIASSYTQR-UHFFFAOYSA-N 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9481—Catalyst preceded by an adsorption device without catalytic function for temporary storage of contaminants, e.g. during cold start
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/508—Sulfur oxides by treating the gases with solids
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/54—Nitrogen compounds
- B01D53/56—Nitrogen oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/62—Carbon oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8603—Removing sulfur compounds
- B01D53/8609—Sulfur oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
- B01D53/8628—Processes characterised by a specific catalyst
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/864—Removing carbon monoxide or hydrocarbons
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/92—Chemical or biological purification of waste gases of engine exhaust gases
- B01D53/94—Chemical or biological purification of waste gases of engine exhaust gases by catalytic processes
- B01D53/9445—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC]
- B01D53/945—Simultaneously removing carbon monoxide, hydrocarbons or nitrogen oxides making use of three-way catalysts [TWC] or four-way-catalysts [FWC] characterised by a specific catalyst
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- 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
- B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
- B01J23/02—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the alkali- or alkaline earth metals or beryllium
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- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/0215—Coating
- B01J37/0221—Coating of particles
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- 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
- B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
- B01J37/02—Impregnation, coating or precipitation
- B01J37/024—Multiple impregnation or coating
- B01J37/0244—Coatings comprising several layers
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/011—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00 having two or more purifying devices arranged in parallel
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0814—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
- F01N3/0842—Nitrogen oxides
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
- F01N3/085—Sulfur or sulfur oxides
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0828—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents characterised by the absorbed or adsorbed substances
- F01N3/0857—Carbon oxides
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
- F01N3/0878—Bypassing absorbents or adsorbents
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
- F01N3/0807—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by using absorbents or adsorbents
- F01N3/0871—Regulation of absorbents or adsorbents, e.g. purging
- F01N3/0885—Regeneration of deteriorated absorbents or adsorbents, e.g. desulfurization of NOx traps
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23R—GENERATING COMBUSTION PRODUCTS OF HIGH PRESSURE OR HIGH VELOCITY, e.g. GAS-TURBINE COMBUSTION CHAMBERS
- F23R3/00—Continuous combustion chambers using liquid or gaseous fuel
- F23R3/40—Continuous combustion chambers using liquid or gaseous fuel characterised by the use of catalytic means
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2255/00—Catalysts
- B01D2255/90—Physical characteristics of catalysts
- B01D2255/91—NOx-storage component incorporated in the catalyst
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2250/00—Combinations of different methods of purification
- F01N2250/12—Combinations of different methods of purification absorption or adsorption, and catalytic conversion
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2290/00—Movable parts or members in exhaust systems for other than for control purposes
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2410/00—By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device
- F01N2410/12—By-passing, at least partially, exhaust from inlet to outlet of apparatus, to atmosphere or to other device in case of absorption, adsorption or desorption of exhaust gas constituents
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
- F01N2570/04—Sulfur or sulfur oxides
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2570/00—Exhaust treating apparatus eliminating, absorbing or adsorbing specific elements or compounds
- F01N2570/14—Nitrogen oxides
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- 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
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
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- 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
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
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Abstract
A method of decreasing the level of NOx, CO and SO2 emissions in a gas turbi ne is disclosed. A catalyst absorber, preferably made of alumina (22)/platinum (24)/carbonate salt (26), is used to oxidize the pollutant oxides and absorb them. The catalyst absorber can then be regenerated and reused. An apparatus for treating the stack gases and a method of making the catalyst absorber ar e also described.
Description
5.
~ WO 95121019 PCT/US95101374 MATERIAL FOR REMOVING CONTAMINANTS FROM GASEOUS STREAM
BACKGROUND OF THE INV.umrnu _ Field of the Invention , r The present invention relates to a process for reducing gaseous pollutants in the air, namely nitrogen oxides (NOX), sulfur oxides and/or carbon monoxide (CO), which are produced by combustion of hydrocarbons or hydrogen in an engine or boiler, and primarily, in a gas turbine. The present invention is also directed to an apparatus for performing the process and a process for making the reactor/catalyst absorber.
Art Background Turbine power plants are becoming the standard for generating electricity because they are so efficient compared to any other form of power manufacture. Turbine power plants that burn methane to produce power for residents and manufacturing facilities in cities also produce carbon monoxide and nitrogen oxide as pollutants.
It is highly desirable to reduce or eliminate these pollutants so that the air is not contaminated as a result of power production.
Initially, the permitted level of pollution by power plants for nitrogen oxides (NOx), which includes nitric oxide (NO) and nitrogen dioxide (N02), was less than 100 parts-per-million (ppm) and the level of carbon monoxide (CO) was to a level of less than 100 ppm. Later, a second step was taken to reduce the NOx to less than 25 ppm and the CO today is still permitted at any amount less than 100 ppm. Using current technology, the output levels of NOx can be reduced to the range of 5 to 9 ppm plus NH3 slippage resulting from the selective catalytic reduction (SCR) technology described below.
The only technology which is currently available to obtain the 5-9 ppm NOx levels is called selective catalytic reduction, in which ammonia is mixed with flue gas and then passed over a catalyst which selectively combines the nitrogen oxides and ammonia to eliminate a major portion of the NOx. One problem with the selective catalytic WO 95121019 ~ PCflUS9510137.t reduction is that as a practical matter, it is only capable of reducing the NOx to the range of 5 to 9 ppm.
Another problem referred to as slippage, is caused by , hazardous ammonia passing through the catalyst.
Another problem of the SCR technology is that the operating conditions required for SCR are only achieved by expensive modifications of the down stream boiler or heat exchanger system.
There have been other technologies for reduction of pollution which have been advanced, such as overwatering in the combustor, and these also have the potential to reduce the NOx pollution, but none of them reduce the NOx to levels much less than 5 to 9 ppm.
In a copending application owned by the assignee of the present application, a system comprising essentially a two step process has been described. In the first step, the stack gases are first contacted with a catalyst under certain conditions which cause the oxidation of certain oxide pollutants, including NO and CO. In the second step, the oxidised pollutants are absorbed in an absorption bed.
It would be desirable to combine the oxidation and absorption steps into a single step performed by a single material.
SUMMARY OF THE INVENTION
The present invention has the capability of reducing hydrocarbon burning engine waste pollutants, and particularly those from a gas turbine, including nitrogen oxide, carbon monoxide and sulfur oxides. The invention, as described in more detail below, includes a novel catalytic absorber and method of making the absorber, a novel process and apparatus capable of reducing air pollutants and 'the method of making the apparatus.
The pollutants from a turbine in a power generating stack are primarily present as NO. The process of the present invention causes oxidation of the NO to N02. This produces N02 from substantially all of the nitrogen oxides (NO). N02 is a much more active material and can be and is absorbed readily by the catalytic absorber from the gas . WO 95121019 PCTIUS95I0137.1 '.
~ WO 95121019 PCT/US95101374 MATERIAL FOR REMOVING CONTAMINANTS FROM GASEOUS STREAM
BACKGROUND OF THE INV.umrnu _ Field of the Invention , r The present invention relates to a process for reducing gaseous pollutants in the air, namely nitrogen oxides (NOX), sulfur oxides and/or carbon monoxide (CO), which are produced by combustion of hydrocarbons or hydrogen in an engine or boiler, and primarily, in a gas turbine. The present invention is also directed to an apparatus for performing the process and a process for making the reactor/catalyst absorber.
Art Background Turbine power plants are becoming the standard for generating electricity because they are so efficient compared to any other form of power manufacture. Turbine power plants that burn methane to produce power for residents and manufacturing facilities in cities also produce carbon monoxide and nitrogen oxide as pollutants.
It is highly desirable to reduce or eliminate these pollutants so that the air is not contaminated as a result of power production.
Initially, the permitted level of pollution by power plants for nitrogen oxides (NOx), which includes nitric oxide (NO) and nitrogen dioxide (N02), was less than 100 parts-per-million (ppm) and the level of carbon monoxide (CO) was to a level of less than 100 ppm. Later, a second step was taken to reduce the NOx to less than 25 ppm and the CO today is still permitted at any amount less than 100 ppm. Using current technology, the output levels of NOx can be reduced to the range of 5 to 9 ppm plus NH3 slippage resulting from the selective catalytic reduction (SCR) technology described below.
The only technology which is currently available to obtain the 5-9 ppm NOx levels is called selective catalytic reduction, in which ammonia is mixed with flue gas and then passed over a catalyst which selectively combines the nitrogen oxides and ammonia to eliminate a major portion of the NOx. One problem with the selective catalytic WO 95121019 ~ PCflUS9510137.t reduction is that as a practical matter, it is only capable of reducing the NOx to the range of 5 to 9 ppm.
Another problem referred to as slippage, is caused by , hazardous ammonia passing through the catalyst.
Another problem of the SCR technology is that the operating conditions required for SCR are only achieved by expensive modifications of the down stream boiler or heat exchanger system.
There have been other technologies for reduction of pollution which have been advanced, such as overwatering in the combustor, and these also have the potential to reduce the NOx pollution, but none of them reduce the NOx to levels much less than 5 to 9 ppm.
In a copending application owned by the assignee of the present application, a system comprising essentially a two step process has been described. In the first step, the stack gases are first contacted with a catalyst under certain conditions which cause the oxidation of certain oxide pollutants, including NO and CO. In the second step, the oxidised pollutants are absorbed in an absorption bed.
It would be desirable to combine the oxidation and absorption steps into a single step performed by a single material.
SUMMARY OF THE INVENTION
The present invention has the capability of reducing hydrocarbon burning engine waste pollutants, and particularly those from a gas turbine, including nitrogen oxide, carbon monoxide and sulfur oxides. The invention, as described in more detail below, includes a novel catalytic absorber and method of making the absorber, a novel process and apparatus capable of reducing air pollutants and 'the method of making the apparatus.
The pollutants from a turbine in a power generating stack are primarily present as NO. The process of the present invention causes oxidation of the NO to N02. This produces N02 from substantially all of the nitrogen oxides (NO). N02 is a much more active material and can be and is absorbed readily by the catalytic absorber from the gas . WO 95121019 PCTIUS95I0137.1 '.
stream even when present at low concentrations in the ppm range.
The turbine exhaust gases are initially at about 1000F
after the shaft energy has been withdrawn from them. These gases are then passed over heat exchangers to remove energy and produce steam while cooling the exhaust or stack gases.
Stack.gases are moving at high velocity depending upon the diameter of the stack, and after heat is removed, the stack gases typically are in the range of 250 to 500'F and travel about 30-50 feet per second. The gas contains 13-15%
oxygen, up to about 12% water, and about 4% carbon dioxide.' This in addition to the pollutants, which are the NOx mixed with approximately 90% NO and 10% N02, CO in the range of 30 to 200 ppm and sulfur dioxide (S02) in the range of about 0.2 to 2.0 ppm when natural gas is the fuel.
The present invention involves a one step/one element process and apparatus to remove the nitrogen oxides, carbon monoxide, and sulfur oxides from the stack gases. Using a combined catalyst/absorber, the nitrogen oxides are oxidized to nitrogen dioxide; the carbon monoxides are oxidized to carbon dioxide, and the sulfur dioxide (SO2) is oxidized to sulfur trioxide (S03). This oxidation occurs ' at temperatures in the range of 150 to about 425'F, and more preferably in the range of 175 to 400F, and most preferably in the range of 200 to 365'F. The space velocity of the exhaust gas may be in the range of 5, 000 to 50,000 per hour (hr'1) and more preferably in the range of 10,000 to 20,000 hr 1, although it is anticipated that a larger range will permit effective operation without an undue reduction in quality of the output gas. As used herein, the term space velocity means volume units of flow per volume units of catalyst per hour.
The catalyst absorber of the present invention absorbs the oxidized oxides so that only a small percentage, generally 10% or less of the initial oxide pollutants, pass through the system and are released. While not being bound to a particular theory, it is presently believed that the reactions which occur are as follows for each of the WO 95121019 PCT/US95/0137.1 ~~.~1~~~
r' ~1 v 1 .1 three pollutants, with an oxidation occurring, followed by a reaction with the carbonate such as Na2C03:
Catalyst CO + 1/2 OZ ---~ C02 C02 + Hz0 + Na2C03 ---~ 2NaHC03 Catalyst No + 1/a o2 ---. No2 2N02 + Na2C03 ---~ NaN03 + NaN02 + COa Catalyst SOZ + 1/2 OZ ---~ S03 S03 + Na2C03 ---~ Na2S04 + C02 SOZ + NaaC03 ---~ Na2SOg + COZ
The catalyst/absorber may be a platinum catalyst supported on alumina with an alkali or alkaline earth carbonate or bicarbonate coating thereon, the carbonate coating being lithium, sodium, potassium or calcium carbonate, and presently the preferred coating is a potassium carbonate.
The absorber, when it ceases to be effective, and specifically, when the level of pollutants emanating from the apparatus after contact with the catalyst absorber increases beyond an acceptable level, can be replaced, and the used absorber can be recharged to an effective status again. Recharging of the catalyst is accomplished by removing the spent (saturated or partially saturated carbonate and replacing the spent carbonate with fresh unreacted carbonate.
BFIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic depiction of the catalyst absorber of the present invention.
Figure la is a drawing of a catalyst absorber sphere in a preferred embodiment.
Figure 1b is a magnified drawing of a portion of the surface of the catalyst absorber sphere of the present invention.
Figure 1c is a drawing of the surface of a monolith catalyst absorber of the present invention.
Figure 2 is a flowchart showing the process of making . W095/21019 ~ , PCTIUS95/0137.t the catalyst of the present invention.
Figure 3 is an illustration of a wheel apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
5 Figure 4 is an illustration of a carousel apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
Figure 5 is an illustration of a fluidized bed apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
Figure 6 is an illustration of a multiple fluidized bed apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
DETATLED DESCRIPTION OF THE T~'NTTfIN
The present invention is directed to a material for removing gaseous pollutants from combustion exhaust streams, in which the material comprises an oxidation catalyst specie disposed on a high surface area support coated with an absorber material. The oxidation catalyst specie is selected from the group of noble metal elements, base metal transitional elements and combinations thereof.
More particularly, the oxidation catalyst species are selected from platinum, palladium, rhodium, cobalt, nickel, iron, copper and molybdenum, and preferably, platinum and rhodium, and most preferably, platinum.
The oxidation catalyst specie concentration is 0.05 to 0.6 percent by weight of the material, and preferably is 0.1 of 0.4 percent by weight of the material, and most preferably is 0.15 to 0.3 percent by weight of the material. More than one element may be used as an oxidation catalyst specie, and under these conditions each of said elements has a concentration in the range of 0.05 to 0.6 percent by weight.
The high surface area support is made of alumina, zirconia, titania, silica or a combination of two or more of these oxides. Preferably, the high surface area support is made of alumina. The surface area of the support is in the range of 5o to 35o square meters per gram, preferably WO 95121019 PCTICTS95l0137;
~~8Z33'~
100 to 325 square meters per gram, and more preferably 200 to 300 square meters per gram. The high surface area support may be coated on a ceramic or metal matrix structure.
The catalyst absorber may be in a shape such as a ~
sphere, solid cylinder, hollow cylinder, star shape or wheel. shape.
The absorber is coated with at least one alkali or alkaline earth compound, which can be hydroxide compound, bicarbonate compound, or carbonate compound, or mixtures of hydroxides and/or bicarbonates and/or carbonated compounds.
Preferably, the absorber comprises substantially all carbonate, and most preferably sodium carbonate, potassium carbonate or calcium carbonate. The absorber is disposed on the material. at a concentration in the range of 0.5 to percent by weight of the material, preferably 5.0 to 15 percent by weight of the material, and most preferably about l0% percent by weight of the material.
The process for making the novel catalyst absorber of 20 the present invention includes applying the oxidation catalyst specie from solution. The solution is preferably a nonaqueous solution. The oxidation catalyst specie may also be applied from chloride free aqueous solution. Once applied the oxidation catalyst specie is dried after application and may be activated after application, possibly by calcining it.
After the catalyst absorber is spent or partially spent, it can be reactivated. Reactivation is accomplished by removing and replacing the spent absorber and disposing of the removed spent absorber. The spent absorber can be used as fertilizer in that it is rich in nitrogen, carbon and sulfur. Alternatively, reactivation is accomplished by decomposing components formed by the combination of pollutants with the absorber and trapping the concentrated pollution gases for disposal or use. The apparatus of the present invention supports the catalyst absorber and contacts the catalyst absorber with a combustion exhaust.
It includes a means for removing spent catalyst absorber . WO 95/21019 ~ 1 8 1 3 3 7 pCf/U595/0137.t from contact with the combustion gases and at the same time moving an equivalent amount of new or regenerated catalyst absorber into contact with the combustion gas to maintain a specified outlet pollution concentration limit. The apparatus is in the shape of a wheel or carousel, or it may be a fluid bed or two or more beds which are alternately used for absorption of pollutant gases and reactivated.
As shown in Figure 1, the catalyst absorber of the present invention can take on different configurations.
Figure la shows a spherical catalyst absorber made up of an alumina sphere l0 with a platinum coating 12 and a carbonate coating 14 thereon. As shown in Figure 1b, the surface of the sphere is very irregular so that there is an extremely large surface area per gram of material as described herein. As shown in Figure lc, the catalyst absorber can be in the form of a monolith surface including a ceramic or stainless steel support 20, an alumina layer 22, a platinum layer 24 and a carbonate layer 26.
The method of making the catalyst absorber is shown in Figure 2. The catalyst/absorber of the present invention is made by starting with high surface area alumina spheres having a surface area of 50 to 350 squares per gram, these spheres being commercially available from several sources, and preferably from La Roche Chemicals, Inc., Baton Rouge, La. The spheres are approximately 1/8 inch in diameter.
It will be appreciated that other forms of supports may be used without departing form the spirit and scope of the present invention. The alumina spheres are washed with distilled water to remove small particles bound loosely to the surface. The spheres are then dried for about 16 hours at 300°F to ensure that all of the cavities and interstices in the spheres are fully dried, and that the surface is free of water. The spheres are then stored in an air-tight container until ready for further processing.
A solution of Pt 2-ethylhexanoate which contained 25% Pt was added to toluene to get a concentration of Pt such that the weight of solution equal to the toluene uptake would wo 9siaiois rcr~s9sioia~a ~18~33'l contain sufficient Pt to give a loading of 0.23 weight percent per weight of alumina. The platinum coated spheres were then dried for l hour at 900°F in air. The spheres are then cooled to approximately room temperature and stored in an air-tight container again. The platinum coated spheres are then coated with an alkali or alkaline earth carbonate or bicarbonate coating, the alkali or alkaline earth carbonate or bicarbonate being selected from lithium, sodium, potassium or calcium carbonate or bicarbonate solution, preferably a sodium carbonate solution at a concentration of 14 percent by weight in distilled water. The water was heated to dissolve all of the sodium carbonate. The carbonate coated spheres were then dried at 300'F for two hours. The final catalyst absorber had a coating of platinum in the amount of 0.23 weight percent added to the alumina, and 10.0 weight percent Na2C03 added to the alumina. The spheres are then disposed in a 3 x 3 x 6 inch wire mesh basket and used as described below.
Alternatively, another form of the catalyst absorber can be made using oeramic or metal monolith supports. Tests were performed by taking a core plug of a metal monolith having approximately 300 openings per square inch, obtaining a core from the monolith of appropriate dimensions for use in the test equipment, coating the surface of the channels in the monolith with alumina from a water slurry, calcining at 900'F for 3 hours, and cooling.
This core is then coated with a platinum coating as described above with respect to the spheres and then the carbonate is applied by the method used for the spheres.
After the catalyst absorber is exhausted or saturated, it can be regenerated. A typical regeneration procedure is as follows:
1. The beads after cooling are transferred to containers approximately 7" x 10" x 5". The containers have closeable lids and inlet and outlet gas or drain lines.
2. Approximately 260 cubic inches of spheres are WO 95/21019 2 I 8 ~. 3 3 ~~ PCT~S9510I374 washed at 190°F with 4 liters of demineralized water for five minutes with stirring.
3. Samples are taken as the liquid is drained off.
The turbine exhaust gases are initially at about 1000F
after the shaft energy has been withdrawn from them. These gases are then passed over heat exchangers to remove energy and produce steam while cooling the exhaust or stack gases.
Stack.gases are moving at high velocity depending upon the diameter of the stack, and after heat is removed, the stack gases typically are in the range of 250 to 500'F and travel about 30-50 feet per second. The gas contains 13-15%
oxygen, up to about 12% water, and about 4% carbon dioxide.' This in addition to the pollutants, which are the NOx mixed with approximately 90% NO and 10% N02, CO in the range of 30 to 200 ppm and sulfur dioxide (S02) in the range of about 0.2 to 2.0 ppm when natural gas is the fuel.
The present invention involves a one step/one element process and apparatus to remove the nitrogen oxides, carbon monoxide, and sulfur oxides from the stack gases. Using a combined catalyst/absorber, the nitrogen oxides are oxidized to nitrogen dioxide; the carbon monoxides are oxidized to carbon dioxide, and the sulfur dioxide (SO2) is oxidized to sulfur trioxide (S03). This oxidation occurs ' at temperatures in the range of 150 to about 425'F, and more preferably in the range of 175 to 400F, and most preferably in the range of 200 to 365'F. The space velocity of the exhaust gas may be in the range of 5, 000 to 50,000 per hour (hr'1) and more preferably in the range of 10,000 to 20,000 hr 1, although it is anticipated that a larger range will permit effective operation without an undue reduction in quality of the output gas. As used herein, the term space velocity means volume units of flow per volume units of catalyst per hour.
The catalyst absorber of the present invention absorbs the oxidized oxides so that only a small percentage, generally 10% or less of the initial oxide pollutants, pass through the system and are released. While not being bound to a particular theory, it is presently believed that the reactions which occur are as follows for each of the WO 95121019 PCT/US95/0137.1 ~~.~1~~~
r' ~1 v 1 .1 three pollutants, with an oxidation occurring, followed by a reaction with the carbonate such as Na2C03:
Catalyst CO + 1/2 OZ ---~ C02 C02 + Hz0 + Na2C03 ---~ 2NaHC03 Catalyst No + 1/a o2 ---. No2 2N02 + Na2C03 ---~ NaN03 + NaN02 + COa Catalyst SOZ + 1/2 OZ ---~ S03 S03 + Na2C03 ---~ Na2S04 + C02 SOZ + NaaC03 ---~ Na2SOg + COZ
The catalyst/absorber may be a platinum catalyst supported on alumina with an alkali or alkaline earth carbonate or bicarbonate coating thereon, the carbonate coating being lithium, sodium, potassium or calcium carbonate, and presently the preferred coating is a potassium carbonate.
The absorber, when it ceases to be effective, and specifically, when the level of pollutants emanating from the apparatus after contact with the catalyst absorber increases beyond an acceptable level, can be replaced, and the used absorber can be recharged to an effective status again. Recharging of the catalyst is accomplished by removing the spent (saturated or partially saturated carbonate and replacing the spent carbonate with fresh unreacted carbonate.
BFIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic depiction of the catalyst absorber of the present invention.
Figure la is a drawing of a catalyst absorber sphere in a preferred embodiment.
Figure 1b is a magnified drawing of a portion of the surface of the catalyst absorber sphere of the present invention.
Figure 1c is a drawing of the surface of a monolith catalyst absorber of the present invention.
Figure 2 is a flowchart showing the process of making . W095/21019 ~ , PCTIUS95/0137.t the catalyst of the present invention.
Figure 3 is an illustration of a wheel apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
5 Figure 4 is an illustration of a carousel apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
Figure 5 is an illustration of a fluidized bed apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
Figure 6 is an illustration of a multiple fluidized bed apparatus for changing and regenerating the oxidation catalyst/absorber of the present invention.
DETATLED DESCRIPTION OF THE T~'NTTfIN
The present invention is directed to a material for removing gaseous pollutants from combustion exhaust streams, in which the material comprises an oxidation catalyst specie disposed on a high surface area support coated with an absorber material. The oxidation catalyst specie is selected from the group of noble metal elements, base metal transitional elements and combinations thereof.
More particularly, the oxidation catalyst species are selected from platinum, palladium, rhodium, cobalt, nickel, iron, copper and molybdenum, and preferably, platinum and rhodium, and most preferably, platinum.
The oxidation catalyst specie concentration is 0.05 to 0.6 percent by weight of the material, and preferably is 0.1 of 0.4 percent by weight of the material, and most preferably is 0.15 to 0.3 percent by weight of the material. More than one element may be used as an oxidation catalyst specie, and under these conditions each of said elements has a concentration in the range of 0.05 to 0.6 percent by weight.
The high surface area support is made of alumina, zirconia, titania, silica or a combination of two or more of these oxides. Preferably, the high surface area support is made of alumina. The surface area of the support is in the range of 5o to 35o square meters per gram, preferably WO 95121019 PCTICTS95l0137;
~~8Z33'~
100 to 325 square meters per gram, and more preferably 200 to 300 square meters per gram. The high surface area support may be coated on a ceramic or metal matrix structure.
The catalyst absorber may be in a shape such as a ~
sphere, solid cylinder, hollow cylinder, star shape or wheel. shape.
The absorber is coated with at least one alkali or alkaline earth compound, which can be hydroxide compound, bicarbonate compound, or carbonate compound, or mixtures of hydroxides and/or bicarbonates and/or carbonated compounds.
Preferably, the absorber comprises substantially all carbonate, and most preferably sodium carbonate, potassium carbonate or calcium carbonate. The absorber is disposed on the material. at a concentration in the range of 0.5 to percent by weight of the material, preferably 5.0 to 15 percent by weight of the material, and most preferably about l0% percent by weight of the material.
The process for making the novel catalyst absorber of 20 the present invention includes applying the oxidation catalyst specie from solution. The solution is preferably a nonaqueous solution. The oxidation catalyst specie may also be applied from chloride free aqueous solution. Once applied the oxidation catalyst specie is dried after application and may be activated after application, possibly by calcining it.
After the catalyst absorber is spent or partially spent, it can be reactivated. Reactivation is accomplished by removing and replacing the spent absorber and disposing of the removed spent absorber. The spent absorber can be used as fertilizer in that it is rich in nitrogen, carbon and sulfur. Alternatively, reactivation is accomplished by decomposing components formed by the combination of pollutants with the absorber and trapping the concentrated pollution gases for disposal or use. The apparatus of the present invention supports the catalyst absorber and contacts the catalyst absorber with a combustion exhaust.
It includes a means for removing spent catalyst absorber . WO 95/21019 ~ 1 8 1 3 3 7 pCf/U595/0137.t from contact with the combustion gases and at the same time moving an equivalent amount of new or regenerated catalyst absorber into contact with the combustion gas to maintain a specified outlet pollution concentration limit. The apparatus is in the shape of a wheel or carousel, or it may be a fluid bed or two or more beds which are alternately used for absorption of pollutant gases and reactivated.
As shown in Figure 1, the catalyst absorber of the present invention can take on different configurations.
Figure la shows a spherical catalyst absorber made up of an alumina sphere l0 with a platinum coating 12 and a carbonate coating 14 thereon. As shown in Figure 1b, the surface of the sphere is very irregular so that there is an extremely large surface area per gram of material as described herein. As shown in Figure lc, the catalyst absorber can be in the form of a monolith surface including a ceramic or stainless steel support 20, an alumina layer 22, a platinum layer 24 and a carbonate layer 26.
The method of making the catalyst absorber is shown in Figure 2. The catalyst/absorber of the present invention is made by starting with high surface area alumina spheres having a surface area of 50 to 350 squares per gram, these spheres being commercially available from several sources, and preferably from La Roche Chemicals, Inc., Baton Rouge, La. The spheres are approximately 1/8 inch in diameter.
It will be appreciated that other forms of supports may be used without departing form the spirit and scope of the present invention. The alumina spheres are washed with distilled water to remove small particles bound loosely to the surface. The spheres are then dried for about 16 hours at 300°F to ensure that all of the cavities and interstices in the spheres are fully dried, and that the surface is free of water. The spheres are then stored in an air-tight container until ready for further processing.
A solution of Pt 2-ethylhexanoate which contained 25% Pt was added to toluene to get a concentration of Pt such that the weight of solution equal to the toluene uptake would wo 9siaiois rcr~s9sioia~a ~18~33'l contain sufficient Pt to give a loading of 0.23 weight percent per weight of alumina. The platinum coated spheres were then dried for l hour at 900°F in air. The spheres are then cooled to approximately room temperature and stored in an air-tight container again. The platinum coated spheres are then coated with an alkali or alkaline earth carbonate or bicarbonate coating, the alkali or alkaline earth carbonate or bicarbonate being selected from lithium, sodium, potassium or calcium carbonate or bicarbonate solution, preferably a sodium carbonate solution at a concentration of 14 percent by weight in distilled water. The water was heated to dissolve all of the sodium carbonate. The carbonate coated spheres were then dried at 300'F for two hours. The final catalyst absorber had a coating of platinum in the amount of 0.23 weight percent added to the alumina, and 10.0 weight percent Na2C03 added to the alumina. The spheres are then disposed in a 3 x 3 x 6 inch wire mesh basket and used as described below.
Alternatively, another form of the catalyst absorber can be made using oeramic or metal monolith supports. Tests were performed by taking a core plug of a metal monolith having approximately 300 openings per square inch, obtaining a core from the monolith of appropriate dimensions for use in the test equipment, coating the surface of the channels in the monolith with alumina from a water slurry, calcining at 900'F for 3 hours, and cooling.
This core is then coated with a platinum coating as described above with respect to the spheres and then the carbonate is applied by the method used for the spheres.
After the catalyst absorber is exhausted or saturated, it can be regenerated. A typical regeneration procedure is as follows:
1. The beads after cooling are transferred to containers approximately 7" x 10" x 5". The containers have closeable lids and inlet and outlet gas or drain lines.
2. Approximately 260 cubic inches of spheres are WO 95/21019 2 I 8 ~. 3 3 ~~ PCT~S9510I374 washed at 190°F with 4 liters of demineralized water for five minutes with stirring.
3. Samples are taken as the liquid is drained off.
4. Three liters of approximately 14% sodium or potassium carbonate solution at 190°F are added to the container.
5. The spheres are stirred and soaked for 20 minutes, or as little as 2 to 5 minutes.
6. Samples are taken as solution is drained.
7. In a 300°F furnace the beads are dried for 45 minutes with approximately 10 scfm heated dry air flowing through the container.
8. The weighed dry beads are returned to the screen container for reuse.
As shown in Figure 3, the catalyst absorber of the present invention can be installed in a wheel apparatus to permit contacting stack gases with the catalyst absorber and regenerating the catalyst absorber after it is saturated or partially saturated. As shown in Figure 3, the wheel apparatus includes an inlet 30 for receiving the combustion gases and stack 32 for exhausting the treated gases, a cylindrical assembly 34 containing catalyst absorber and a regenerating unit 36 for regenerating the spent catalyst, the regenerating unit having an inlet 37 and outlet 38 for replenishing fresh regeneration fluid.
The inner wall 39 and outer wall 40 of a portion of the wheel adjacent the stack 32 are perforated or otherwise vented to permit passage of the gas therethrough. The inner and/or outer walls 41 and 42 of the remainder of the 3o wheel is closed so that the exhaust gases only exhaust through the stack 32. A drive 44 is used to rotate the wheel either discretely or continuously. Arrow A
designates the direction of the drive 44 rotation and arrow B indicates the direction of the wheel rotation.
As shown in Figure 4, an alternative arrangement for the catalyst absorber is disclosed, in which a carousel is used. The stack gases enter through the inlet 50 and exit through the stack 52. The catalyst absorber is inserted in W095/ZI019 J , ~. PCT/US95101374 line with the stack gases at 54, and when spent is retracted into the carousel at 56 and a new absorber installed. The spent catalyst absorber is then regenerated. Fresh regeneration fluid enters through inlet 5 57 and is removed through outlet 58.
As shown in Figure 5, a fluidized bed apparatus is disclosed. This apparatus has a combustion gas inlet 60 and stack outlet 70. There is a fluidized bed 62 in line with the gas which contains active catalyst absorber. A
10 portion of the catalyst absorber is removed from the fluidized bed and moved to the regeneration unit 64.
Regeneration fluid is sent into the regenerator at 65 and is removed by the fluid separator 66.
As shown in Figure 6, a multiple fluidized bed apparatus is disclosed. This apparatus has a combustion gas inlet 71 and stack outlet 80. There is a first fluidized bed 72 in line with the gas which contains active catalyst absorber.
There is a second fluidized bed 73 which is being regenerated. The first fluidized bed has inlet 76 and outlet 77 with valves to permit regeneration fluid in and out. The second fluidized bed has inlet 74 and outlet 75 with valves to permit regeneration fluid in and out. Valve 78 controls whether combustion gases go to the first or second fluidized bed.
In the following examples, gas measurements were made as follows; CO was measured by a TECO model 48 infrared analyzer, C02 was measured by a Horiba Co2 infrared meter and NO and N02 were measured using a TECO model #10R
chemiluminescent detector with a stainless steel converter.
Sulfur oxides were measured using a TECO model #43a Pulsed Fluorescence S02 Analyzer.
Examples of the performance of the present invention are set forth below.
Experiment No. 1 In each of the following experiments, the starting gas was obtained from a slip stream from the turbine exhaust from a cogeneration plant turbine. The catalyst absorber was disposed in two wire mesh baskets having a 3 inch by 3 W0 95121019 pCTlUS9510137d inch by 6 inch geometry and placed in line with the slip stream in series to min imize any edge effects nd ensure a that all of the slip with the stream comes in contact catalyst absorber . The space velocity of the sl ip stream was 18,000 hr 1. The o temperatures listed ind icate the tw temperature for the upstream firs t basket and the temperature for the downstream second basket.
all pollutant measurements are in ppm. NOx is the total concentration of nitrogen oxide (NO) nd nitrogen a dioxide (N02).
~Tnit-;a~ Starting ollutant Levels P
CO in. 10.98 ppm NO in, 29.0 ppm NOx in, 33.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (F) (PPm) (PPm) (PPm) :15 230 216 0.36 3.0 3.0 :30 355 323 0.18 3.0 4.0 :45 355 328 0.20 3.0 4.0 1 hr. 354 329 0.19 3.0 5.0 1:15 352 328 0.20 3.0 5.0 1:30 351 328 0.23 2.5 6.0 1:45 350 327 0.25 3.0 7p 2 hrs. 348 325 0.17 7.0 gp 2:15 348 325 0.17 7.0 8.0 2:30 348 325 0.19 8.0 10.0 2:45 348 325 0.18 9.0 10.0 3 hrs. 348 325 0.18 10.0 11.0 3:15 347 325 0.17 11.0 12.0 3:30 346 323 0.17 11.0 12.0 3:45 346 322 0.18 12.0 13.0 Experiment No.
1-a The catalyst absorber and the was regenerated experiment was ru n again under the same conditions using the regenerated catalyst absorber.
Tn~tial Startinct ollutant Tevels P
CO in. 9.91 ppm NO in, 30.0 ppm ' NOx in, 36.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (F) (ppm) (ppm) (ppm) :15 135 162 2.49 16.0 16.0 :30 365 160 .13 5.0 5.0 WO 95121019 21 ~3 I 3 3'~ '' a r~ ~ °'' PGT/1T59510137.1 :45 363 351 .05 2.0 2.0 1 hr. 363 353 .05 2.5 2.5 1:15 362 353 .08 4.0 4.0 1:30 362 352 .05 4.5 5.0 -1:45 362 354 .07 5.5 6.0 2 hrs. 362 354 .07 6.0 7.0 2:15 362 354 .07 7.0 8.0 2:30 361 353 .06 7.5 8.5 2:45 362 354 .09 8.5 9.5 3 hrs. 362 354 .08 9.0 10.0 3:15 362 354 .08 9.0 10.5 3:30 363 355 .08 10.0 11.5 3:45 363 356 .08 10.0 12.0 4 hrs. 364 356 .07 10.5 12.5 It is believed that the first reading 15 minutes at showed high po7-lution because the temperature level of the catalyst the necessary absorber temperature was below for oxidation.
Experiment -b No. 1 The catalyst absorber regenerated was a second time and the experiment run aga in unde r the same conditions was using absorber.
the twice regenerated catalyst ?.~i~t~a~Startncr Pol lutant Levels Co in. 13.16 ppm NO in, 26.0 ppm NOx in, 32.5 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) ('F) (ppm) (ppm) (ppm) :15 133 134 0.2 23.0 23.0 :30 296 139 3.02 16.0 16.0 :45 313 142 0.43 7.5 7.5 1 hr. 296 296 0.30 6.0 6.0 1:15 285 285 0.34 7.0 7.0 1:30 279 278 0.37 8.5 8.5 1:45 282 273 0.40 10.0 10.0 2 hrs. 304 290 0.30 9.5 9.5 2:15 320 308 0.25 9.5 10.0 2:30 330 319 0.22 10.0 11.0 2:45 339 329 0.20 10.5 12.0 3 hrs. 343 334 0.20 11.5 12.5 3:15 347 338 0.22 12.0 14.0 Experiment No. 1-c The catalyst absorber was regenerated again and the experiment was run again under the same conditions using the three time regenerated catalyst absorber.
wo9snlo19 Z~'~'~33~ , , ~nii'.i.~1Ctartinn Dnrr"ta..a-......1j r CO in. 12.13 ppm NO in, 28.0 ppm NOx in, 34.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (PPm) (PPm) (ppm) ('F) :15 142 155 7.61 20.0 20.0 :30 352 195 0.30 3.0 3.0 :45 350 342 0.22 2.5 2.5 1 hr. 351 342 0.23 3.0 3_5 1:15 351 343 0.24 4.0 4.5 1:30 351 345 0.24 5.0 5.5 1:45 351 344 0.27 6.0 6.5 2 hrs. 352 345 0.24 6.5 7.5 2:15 351 346 0.24 8.0 9.D
2:30 351 345 0.23 g.D g,D
2:45 351 345 0.30 9.0 10.0 3 hrs. 350 343 D.37 9.5 11.0 3:15 350 342 0.28 10.0 12.0 3:30 348 341 0.30 11.0 12.0 3:45 348 341 0.30 12.0 13.5 Experiment No. 1-d The catalyst absorber and the was regenerated again experiment was run again under the same conditions using the four time regenerated catalyst absorber.
Ini ti Starting ~ "+a>,+ ~ 1 a~ r.
CO in. 13.16 ppm 3D NO in, 28.0 ppm NOx in, 34.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (F) (ppm) (PPm) (PPm) :15 132 132 10.28 22.0 23.0 :30 353 143 1.22 8.0 g.p :45 351 259 0.45 4.0 4_5 1 hr. 350 338 0.42 4.0 4.5 1:15 349 338 0.43 5.0 5.5 1:30 349 338 0.41 6.0 6.5 1:45 349 339 0.41 7.0 7.5 2 hrs. 349 339 0.42 8.0 9.p 2:15 348 338 0.46 8.5 g_5 2:30 349 339 0.45 9.5 10.5 2:45 349 339 0.49 10.0 11.5 3 hrs. 349 339 0.48 10.5 12.0 3:15 350- 340 0.55 11.0 13.0 Experiment No. 2 The conditionsfor this series of experiments was the same as those for Experiment No. 1. This series was begun WO 95121019 PCT/US9510I37.1 ~v w, with a absor7~er the same type and new catalyst of configu ration as scribed Experiment No. 1.
de above for initial Starting llutant Levels .
Po CO in. 10.98 ppm NO in, 29.0 ppm NOx in, 33.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min ('F) ('F) (ppm) (ppm) (ppm) :15 345 225 0.20 2.0 2.0 :30 348 308 0.19 2.0 2.5 :45 350 315 0.22 2.0 2.0 1 hr. 350 317 0.24 2.0 2.5 1:15 351 317 0.23 2.5 2.5 1:30 351 318 0.23 3.0 3.0 1:45 351 317 0.24 3.5 4.0 2 hrs. 351 317 0.26 5.0 7.0 2:15 350 318 0.24 6.0 8.0 2:30 351 319 0.25 8.0 10.0 2:45 351 320 0.23 10.0 11.0 3 hrs. 352 320 0.26 10.0 12.0 3:15 352 320 0.22 I1.0 12.0 3:30 353 321 0.26 11.0 13.0 Experiment No.
2-a The catalyst absorber and the was regenerated experiment again same conditions was run under using the the regenerated absorber.
catalyst initial Starting llutant Levels Po CO in. 11 ppm NO in, 29 ppm NOx in, 33 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min ('F) (F) (ppm) (ppm) (ppm) :15 144 142 7.75 20.0 20.0 :30 374 142 0.39 5.0 5.0 :45 372 358 0.17 2.0 2.0 1 hr. 371 362 0.15 1.5 2.0 1:15 370 363 0.17 3.0 3.5 1:30 370 363 0.17 4.0 4.5 1:45 368 361 0.18 4.5 5.0 2 hrs. 367 369 0.13 5.0 6.0 2:15 367 360 0.15 6.5 7.5 2:30 366 358 0.17 7.5 8.5 2:45 366 359 0.18 8.0 9.0 3 hrs. 366 358 0.14 9.0 10.0 3:15 366 358 0.17 10.0 11.0 3:30 365 358 0.17 10.0 11.5 3:45 363 356 0.18 10.5 12.0 4 hrs. 362 354 0.17 11.5 13.0 ~18~.~37 . W095/21019 PCT/C1S95/0137.t Experiment No.
2-b The catalyst absorber was regenerated and the again experiment run again unde r the same conditions was using the twi ce regenerated absorber.
catalyst 5 'rnitiai Starting Poll+an TPVa 1s CO in. 11 ppm NO in, 29 ppm NOx in, 33 ppm 10 Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min ('F) ('F) (ppm) (ppm) (ppm) :15 186 142 5.53 18.0 18.0 :30 279 144 2.65 12.0 13.0 15 :45 275 255 0.85 7.0 7.0 1 hr. 271 254 0.65 7.0 7,0 1:15 267 253 0.77 9.0 9.0 1:30 274 255 0.78 10.0 10.0 1:45 283 262 0.73 11.0 11.0 2 hrs. 284 266 0.68 11.0 11.5 2:15 282 266 0.68 13.0 13.0 Experiment No.
2-c The catalyst absorber was regenerated and the again experiment same conditions was run using again under the the three lyst time absorber.
regenerated cata r_n_i_t,'_alStartinc LPollutant T.Pve1s CO in.
As shown in Figure 3, the catalyst absorber of the present invention can be installed in a wheel apparatus to permit contacting stack gases with the catalyst absorber and regenerating the catalyst absorber after it is saturated or partially saturated. As shown in Figure 3, the wheel apparatus includes an inlet 30 for receiving the combustion gases and stack 32 for exhausting the treated gases, a cylindrical assembly 34 containing catalyst absorber and a regenerating unit 36 for regenerating the spent catalyst, the regenerating unit having an inlet 37 and outlet 38 for replenishing fresh regeneration fluid.
The inner wall 39 and outer wall 40 of a portion of the wheel adjacent the stack 32 are perforated or otherwise vented to permit passage of the gas therethrough. The inner and/or outer walls 41 and 42 of the remainder of the 3o wheel is closed so that the exhaust gases only exhaust through the stack 32. A drive 44 is used to rotate the wheel either discretely or continuously. Arrow A
designates the direction of the drive 44 rotation and arrow B indicates the direction of the wheel rotation.
As shown in Figure 4, an alternative arrangement for the catalyst absorber is disclosed, in which a carousel is used. The stack gases enter through the inlet 50 and exit through the stack 52. The catalyst absorber is inserted in W095/ZI019 J , ~. PCT/US95101374 line with the stack gases at 54, and when spent is retracted into the carousel at 56 and a new absorber installed. The spent catalyst absorber is then regenerated. Fresh regeneration fluid enters through inlet 5 57 and is removed through outlet 58.
As shown in Figure 5, a fluidized bed apparatus is disclosed. This apparatus has a combustion gas inlet 60 and stack outlet 70. There is a fluidized bed 62 in line with the gas which contains active catalyst absorber. A
10 portion of the catalyst absorber is removed from the fluidized bed and moved to the regeneration unit 64.
Regeneration fluid is sent into the regenerator at 65 and is removed by the fluid separator 66.
As shown in Figure 6, a multiple fluidized bed apparatus is disclosed. This apparatus has a combustion gas inlet 71 and stack outlet 80. There is a first fluidized bed 72 in line with the gas which contains active catalyst absorber.
There is a second fluidized bed 73 which is being regenerated. The first fluidized bed has inlet 76 and outlet 77 with valves to permit regeneration fluid in and out. The second fluidized bed has inlet 74 and outlet 75 with valves to permit regeneration fluid in and out. Valve 78 controls whether combustion gases go to the first or second fluidized bed.
In the following examples, gas measurements were made as follows; CO was measured by a TECO model 48 infrared analyzer, C02 was measured by a Horiba Co2 infrared meter and NO and N02 were measured using a TECO model #10R
chemiluminescent detector with a stainless steel converter.
Sulfur oxides were measured using a TECO model #43a Pulsed Fluorescence S02 Analyzer.
Examples of the performance of the present invention are set forth below.
Experiment No. 1 In each of the following experiments, the starting gas was obtained from a slip stream from the turbine exhaust from a cogeneration plant turbine. The catalyst absorber was disposed in two wire mesh baskets having a 3 inch by 3 W0 95121019 pCTlUS9510137d inch by 6 inch geometry and placed in line with the slip stream in series to min imize any edge effects nd ensure a that all of the slip with the stream comes in contact catalyst absorber . The space velocity of the sl ip stream was 18,000 hr 1. The o temperatures listed ind icate the tw temperature for the upstream firs t basket and the temperature for the downstream second basket.
all pollutant measurements are in ppm. NOx is the total concentration of nitrogen oxide (NO) nd nitrogen a dioxide (N02).
~Tnit-;a~ Starting ollutant Levels P
CO in. 10.98 ppm NO in, 29.0 ppm NOx in, 33.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (F) (PPm) (PPm) (PPm) :15 230 216 0.36 3.0 3.0 :30 355 323 0.18 3.0 4.0 :45 355 328 0.20 3.0 4.0 1 hr. 354 329 0.19 3.0 5.0 1:15 352 328 0.20 3.0 5.0 1:30 351 328 0.23 2.5 6.0 1:45 350 327 0.25 3.0 7p 2 hrs. 348 325 0.17 7.0 gp 2:15 348 325 0.17 7.0 8.0 2:30 348 325 0.19 8.0 10.0 2:45 348 325 0.18 9.0 10.0 3 hrs. 348 325 0.18 10.0 11.0 3:15 347 325 0.17 11.0 12.0 3:30 346 323 0.17 11.0 12.0 3:45 346 322 0.18 12.0 13.0 Experiment No.
1-a The catalyst absorber and the was regenerated experiment was ru n again under the same conditions using the regenerated catalyst absorber.
Tn~tial Startinct ollutant Tevels P
CO in. 9.91 ppm NO in, 30.0 ppm ' NOx in, 36.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (F) (ppm) (ppm) (ppm) :15 135 162 2.49 16.0 16.0 :30 365 160 .13 5.0 5.0 WO 95121019 21 ~3 I 3 3'~ '' a r~ ~ °'' PGT/1T59510137.1 :45 363 351 .05 2.0 2.0 1 hr. 363 353 .05 2.5 2.5 1:15 362 353 .08 4.0 4.0 1:30 362 352 .05 4.5 5.0 -1:45 362 354 .07 5.5 6.0 2 hrs. 362 354 .07 6.0 7.0 2:15 362 354 .07 7.0 8.0 2:30 361 353 .06 7.5 8.5 2:45 362 354 .09 8.5 9.5 3 hrs. 362 354 .08 9.0 10.0 3:15 362 354 .08 9.0 10.5 3:30 363 355 .08 10.0 11.5 3:45 363 356 .08 10.0 12.0 4 hrs. 364 356 .07 10.5 12.5 It is believed that the first reading 15 minutes at showed high po7-lution because the temperature level of the catalyst the necessary absorber temperature was below for oxidation.
Experiment -b No. 1 The catalyst absorber regenerated was a second time and the experiment run aga in unde r the same conditions was using absorber.
the twice regenerated catalyst ?.~i~t~a~Startncr Pol lutant Levels Co in. 13.16 ppm NO in, 26.0 ppm NOx in, 32.5 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) ('F) (ppm) (ppm) (ppm) :15 133 134 0.2 23.0 23.0 :30 296 139 3.02 16.0 16.0 :45 313 142 0.43 7.5 7.5 1 hr. 296 296 0.30 6.0 6.0 1:15 285 285 0.34 7.0 7.0 1:30 279 278 0.37 8.5 8.5 1:45 282 273 0.40 10.0 10.0 2 hrs. 304 290 0.30 9.5 9.5 2:15 320 308 0.25 9.5 10.0 2:30 330 319 0.22 10.0 11.0 2:45 339 329 0.20 10.5 12.0 3 hrs. 343 334 0.20 11.5 12.5 3:15 347 338 0.22 12.0 14.0 Experiment No. 1-c The catalyst absorber was regenerated again and the experiment was run again under the same conditions using the three time regenerated catalyst absorber.
wo9snlo19 Z~'~'~33~ , , ~nii'.i.~1Ctartinn Dnrr"ta..a-......1j r CO in. 12.13 ppm NO in, 28.0 ppm NOx in, 34.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (PPm) (PPm) (ppm) ('F) :15 142 155 7.61 20.0 20.0 :30 352 195 0.30 3.0 3.0 :45 350 342 0.22 2.5 2.5 1 hr. 351 342 0.23 3.0 3_5 1:15 351 343 0.24 4.0 4.5 1:30 351 345 0.24 5.0 5.5 1:45 351 344 0.27 6.0 6.5 2 hrs. 352 345 0.24 6.5 7.5 2:15 351 346 0.24 8.0 9.D
2:30 351 345 0.23 g.D g,D
2:45 351 345 0.30 9.0 10.0 3 hrs. 350 343 D.37 9.5 11.0 3:15 350 342 0.28 10.0 12.0 3:30 348 341 0.30 11.0 12.0 3:45 348 341 0.30 12.0 13.5 Experiment No. 1-d The catalyst absorber and the was regenerated again experiment was run again under the same conditions using the four time regenerated catalyst absorber.
Ini ti Starting ~ "+a>,+ ~ 1 a~ r.
CO in. 13.16 ppm 3D NO in, 28.0 ppm NOx in, 34.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min (F) (F) (ppm) (PPm) (PPm) :15 132 132 10.28 22.0 23.0 :30 353 143 1.22 8.0 g.p :45 351 259 0.45 4.0 4_5 1 hr. 350 338 0.42 4.0 4.5 1:15 349 338 0.43 5.0 5.5 1:30 349 338 0.41 6.0 6.5 1:45 349 339 0.41 7.0 7.5 2 hrs. 349 339 0.42 8.0 9.p 2:15 348 338 0.46 8.5 g_5 2:30 349 339 0.45 9.5 10.5 2:45 349 339 0.49 10.0 11.5 3 hrs. 349 339 0.48 10.5 12.0 3:15 350- 340 0.55 11.0 13.0 Experiment No. 2 The conditionsfor this series of experiments was the same as those for Experiment No. 1. This series was begun WO 95121019 PCT/US9510I37.1 ~v w, with a absor7~er the same type and new catalyst of configu ration as scribed Experiment No. 1.
de above for initial Starting llutant Levels .
Po CO in. 10.98 ppm NO in, 29.0 ppm NOx in, 33.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min ('F) ('F) (ppm) (ppm) (ppm) :15 345 225 0.20 2.0 2.0 :30 348 308 0.19 2.0 2.5 :45 350 315 0.22 2.0 2.0 1 hr. 350 317 0.24 2.0 2.5 1:15 351 317 0.23 2.5 2.5 1:30 351 318 0.23 3.0 3.0 1:45 351 317 0.24 3.5 4.0 2 hrs. 351 317 0.26 5.0 7.0 2:15 350 318 0.24 6.0 8.0 2:30 351 319 0.25 8.0 10.0 2:45 351 320 0.23 10.0 11.0 3 hrs. 352 320 0.26 10.0 12.0 3:15 352 320 0.22 I1.0 12.0 3:30 353 321 0.26 11.0 13.0 Experiment No.
2-a The catalyst absorber and the was regenerated experiment again same conditions was run under using the the regenerated absorber.
catalyst initial Starting llutant Levels Po CO in. 11 ppm NO in, 29 ppm NOx in, 33 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min ('F) (F) (ppm) (ppm) (ppm) :15 144 142 7.75 20.0 20.0 :30 374 142 0.39 5.0 5.0 :45 372 358 0.17 2.0 2.0 1 hr. 371 362 0.15 1.5 2.0 1:15 370 363 0.17 3.0 3.5 1:30 370 363 0.17 4.0 4.5 1:45 368 361 0.18 4.5 5.0 2 hrs. 367 369 0.13 5.0 6.0 2:15 367 360 0.15 6.5 7.5 2:30 366 358 0.17 7.5 8.5 2:45 366 359 0.18 8.0 9.0 3 hrs. 366 358 0.14 9.0 10.0 3:15 366 358 0.17 10.0 11.0 3:30 365 358 0.17 10.0 11.5 3:45 363 356 0.18 10.5 12.0 4 hrs. 362 354 0.17 11.5 13.0 ~18~.~37 . W095/21019 PCT/C1S95/0137.t Experiment No.
2-b The catalyst absorber was regenerated and the again experiment run again unde r the same conditions was using the twi ce regenerated absorber.
catalyst 5 'rnitiai Starting Poll+an TPVa 1s CO in. 11 ppm NO in, 29 ppm NOx in, 33 ppm 10 Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min ('F) ('F) (ppm) (ppm) (ppm) :15 186 142 5.53 18.0 18.0 :30 279 144 2.65 12.0 13.0 15 :45 275 255 0.85 7.0 7.0 1 hr. 271 254 0.65 7.0 7,0 1:15 267 253 0.77 9.0 9.0 1:30 274 255 0.78 10.0 10.0 1:45 283 262 0.73 11.0 11.0 2 hrs. 284 266 0.68 11.0 11.5 2:15 282 266 0.68 13.0 13.0 Experiment No.
2-c The catalyst absorber was regenerated and the again experiment same conditions was run using again under the the three lyst time absorber.
regenerated cata r_n_i_t,'_alStartinc LPollutant T.Pve1s CO in.
9.05 ppm NO in, 26.0 ppm NOx in, 32.0 ppm Time Temp 1 Temp 2 CO out NO out NOx out Hrs:Min ('F) (F) (ppm) (ppm) (ppm) :15 354 142 1.06 7.0 7,0 :30 356 150 0.49 2.0 2.0 :45 354 338 0.41 2.0 2.0 1 hr. 351 337 0.43 2.0 3.0 1:15 352 338 0.45 3.0 5.0 1:30 352 339 0.50 6.0 7.0 1:45 352 337 0.50 7.0 g.p 2 hrs. 351 338 0.50 8.0 9.0 2:15 350 336 0.49 8.5 g.5 2:30 349 335 0.50 9.0 10.0 2:45 348 334 0.56 10.0 11.0 3 hrs. 348 334 0.58 11.0 12.0 Experiment 3 First Run -This experiment onolith core catalyst was run using a m in a laboratory set up under the conditions set forth below. The space 10,000 initial velocity hr-ls.
was The 21813:37 . 1 WO 95121019 " % ~ PGT/1TS95/0137a starting pollutant levels are set out at time zero (0) minutes. Only one catalyst absorber unit was used and the temperature was measured just before the catalyst absorber.
Time Temp CO NOx NO Sulfur (S02) Minutes ('F) (ppm) (ppm) (ppm) (ppm) Input 351 18.0 33.0 29.0 0.5 concentrations 1 405 0 1.0 0.5 2 415 1.0 0.5 0.35 5 420 0.75 0.059 10 480 0.45 0.004 401 0 0.4 0 15 32 380 2.4 0.004 42 408 2.3 0.007 48 360 1.5 0.001 50 344 1.85 0.002 64 296 5.2 4.2 0.016 20 75 291 8.6 7.1 0.023 85 291 9.0 0.037 Experiment 3 Second n - Ru The catalyst absorber was enerated and the experiment reg was run again under the same conditions using the regenerated lyst absorber.
cata Time Temp CO NOx NO Sulfur (S02) Minutes (F) (ppm) (ppm) (ppm) (ppm) Input 20.0 34.0 31.0 0.51 Concentrations 0.5 378 0.1 1.8 0.08 1 369 0.1 1.8 0.02 2 343 0.1 1.75 1.55 0.32 3 326 0.1 1.75 1.6 0.19 6 300 0.1 2.0 1.85 0.05 10 286 0.1 2.6 2.6 0.025 12 284 0.1 3.0 0.021 21 287 0.1 5.0 0.021 25 288 0.1 6.2 6.2 0.024 30 291 0.1 9.0 7.9 0.02 47 300 0.1 13.5 12.5 0.05 Experiment No. 4 In the foll owing experiment, starting gas was the obtained from slip stream fromthe turb ine exhaust from a a cogeneration with Exp eriments 1 and plant turbine, 2.
as The catalyst as in Experiments -has the same configuration 1 and 2. The the slip stream was 18,000 space velocity of hr 1. The upstream first basket was temperature for the . W0 95121019 2 ~ $13 3 "~f ' PCTICTS9510137;
330F and 300F for the downstream second basket. All pollutant measurements in ppm.
are Time O NOx NO Np2 Minutes (ppm) (ppm) (ppm) (ppm) Input 20.0 33 27 6 Concentrations 0 0 1.5 1.5 p .5 0 1.5 1.5 0 1.5 0 5 5 10 Apparatus To apply the catalyst absorber to the continuous reduction of gaseous pollutants in stack gases, an apparatus is required. The catalyst absorber is moved into contact with the stack gas and remains there until the outlet levels of carbon monoxide, nitrogen oxides and/or sulfur oxides exceed some specified low concentrations.
The catalyst absorber is then moved out of contact with the stack gases for regeneration while being replaced with fresh or previously regenerated catalyst absorber. The regenerated catalyst absorber is cycled back into contact with the stack gases in sequence.
The apparatus to apply the catalyst absorber of the present invention can be in the form of a wheel or carousel, a portion of which is in contact with the stack gas and a portion of which is outside of contact with the stack gas. In this case, the catalyst absorber is mounted to the wheel and moves in and out of the stack gas stream as the wheel rotates. The apparatus may alternatively be a moving continuous belt with the catalyst absorber being disposed on the belt. Alternatively, a fluidized bed of the alumina spheres of the catalyst absorbed can be located in the stack gas stream. In this embodiment a small fraction of the catalyst absorber, for example,, one percent per minute, is continuously removed, regenerated and returned. Any other apparatus could be used to accomplish the goals specified herein, the choice of such apparatus depending upon the individual applications.
It would be obvious to a person of ordinary skill in the WO 95121019 ' PCTIUS95/0137.t art that a number of changes and modifications can be made to the presently described process, apparatus and methods without departing from the spirit and scope of the present invention. It is contemplated that the present invention is encompassed by the claims as presented herein and by all variations thereof coming within the scope of equivalents accorded thereto.
was The 21813:37 . 1 WO 95121019 " % ~ PGT/1TS95/0137a starting pollutant levels are set out at time zero (0) minutes. Only one catalyst absorber unit was used and the temperature was measured just before the catalyst absorber.
Time Temp CO NOx NO Sulfur (S02) Minutes ('F) (ppm) (ppm) (ppm) (ppm) Input 351 18.0 33.0 29.0 0.5 concentrations 1 405 0 1.0 0.5 2 415 1.0 0.5 0.35 5 420 0.75 0.059 10 480 0.45 0.004 401 0 0.4 0 15 32 380 2.4 0.004 42 408 2.3 0.007 48 360 1.5 0.001 50 344 1.85 0.002 64 296 5.2 4.2 0.016 20 75 291 8.6 7.1 0.023 85 291 9.0 0.037 Experiment 3 Second n - Ru The catalyst absorber was enerated and the experiment reg was run again under the same conditions using the regenerated lyst absorber.
cata Time Temp CO NOx NO Sulfur (S02) Minutes (F) (ppm) (ppm) (ppm) (ppm) Input 20.0 34.0 31.0 0.51 Concentrations 0.5 378 0.1 1.8 0.08 1 369 0.1 1.8 0.02 2 343 0.1 1.75 1.55 0.32 3 326 0.1 1.75 1.6 0.19 6 300 0.1 2.0 1.85 0.05 10 286 0.1 2.6 2.6 0.025 12 284 0.1 3.0 0.021 21 287 0.1 5.0 0.021 25 288 0.1 6.2 6.2 0.024 30 291 0.1 9.0 7.9 0.02 47 300 0.1 13.5 12.5 0.05 Experiment No. 4 In the foll owing experiment, starting gas was the obtained from slip stream fromthe turb ine exhaust from a a cogeneration with Exp eriments 1 and plant turbine, 2.
as The catalyst as in Experiments -has the same configuration 1 and 2. The the slip stream was 18,000 space velocity of hr 1. The upstream first basket was temperature for the . W0 95121019 2 ~ $13 3 "~f ' PCTICTS9510137;
330F and 300F for the downstream second basket. All pollutant measurements in ppm.
are Time O NOx NO Np2 Minutes (ppm) (ppm) (ppm) (ppm) Input 20.0 33 27 6 Concentrations 0 0 1.5 1.5 p .5 0 1.5 1.5 0 1.5 0 5 5 10 Apparatus To apply the catalyst absorber to the continuous reduction of gaseous pollutants in stack gases, an apparatus is required. The catalyst absorber is moved into contact with the stack gas and remains there until the outlet levels of carbon monoxide, nitrogen oxides and/or sulfur oxides exceed some specified low concentrations.
The catalyst absorber is then moved out of contact with the stack gases for regeneration while being replaced with fresh or previously regenerated catalyst absorber. The regenerated catalyst absorber is cycled back into contact with the stack gases in sequence.
The apparatus to apply the catalyst absorber of the present invention can be in the form of a wheel or carousel, a portion of which is in contact with the stack gas and a portion of which is outside of contact with the stack gas. In this case, the catalyst absorber is mounted to the wheel and moves in and out of the stack gas stream as the wheel rotates. The apparatus may alternatively be a moving continuous belt with the catalyst absorber being disposed on the belt. Alternatively, a fluidized bed of the alumina spheres of the catalyst absorbed can be located in the stack gas stream. In this embodiment a small fraction of the catalyst absorber, for example,, one percent per minute, is continuously removed, regenerated and returned. Any other apparatus could be used to accomplish the goals specified herein, the choice of such apparatus depending upon the individual applications.
It would be obvious to a person of ordinary skill in the WO 95121019 ' PCTIUS95/0137.t art that a number of changes and modifications can be made to the presently described process, apparatus and methods without departing from the spirit and scope of the present invention. It is contemplated that the present invention is encompassed by the claims as presented herein and by all variations thereof coming within the scope of equivalents accorded thereto.
Claims (48)
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A material for removing nitrogen oxides, sulfur oxides and carbon monoxide pollutants from combustion exhaust, comprising an oxidation catalyst specie selected from platinum, palladium, rhodium, cobalt, nickel, iron, copper, molybdenum or combinations thereof disposed on a high surface area support, said support having a surface area of 50 to 350 square meters per gram and containing alumina, zirconia, titania, silica or a combination of two or more of these oxides, said catalytic component being intimately and entirely coated with an absorber material selected from a hydroxide, carbonate, bicarbonate or mixture thereof of an alkali or alkaline earth or mixtures thereof, said oxidation catalyst specie concentration is 0.05 to 0.6 percent by weight of the material and, wherein the absorber is disposed on said material at a concentration in the range of 0.5 to 20 percent by weight of the material.
2. The material of claim 1, wherein the oxidation catalyst specie is platinum.
3. The material of claim 1, wherein the oxidation catalyst specie concentration is 0.1 to 0.4 percent by weight of the material.
4. The material of claim 3, wherein the oxidation catalyst specie concentration is 0.15 to 0.3 percent by weight of the material.
5. The material of claim 1, wherein more than one element is used as an oxidation catalyst specie and wherein each of said elements has a concentration in the range of 0.05 to 0.6 percent by weight.
6. The material of claim 5, wherein the high surface area support contains alumina.
7. The material of claim 6, wherein the surface area of the support is 100 to 325 square meters per gram.
8. The material of claim 7, wherein the surface area of the support is 200 to 300 square meters per gram.
9. The material of claim 1, wherein said alkali metal is selected from the group consisting of lithium, sodium and potassium.
10. The material of claim 1, wherein at least a portion of the absorber comprises a hydroxide compound.
11. The material of claim 1, wherein at least a portion of the absorber comprises a bicarbonate compound.
12. The material of claim 1, wherein at least a portion of the absorber comprises a carbonate compound.
13. The material of claim 1, wherein the absorber comprises mixtures of hydroxides and/or bicarbonates and/or carbonated compounds.
14. The material of claim 12, wherein the absorber consists essentially of carbonate.
15. The material of claim 14, wherein the absorber consists essentially of sodium carbonate.
16. The material of claim 14, wherein the absorber consists essentially of potassium carbonate.
17. The material according to claim 10, wherein the absorber consists essentially of potassium.
18. The material of claim 17, wherein the absorber concentration is 5.0 to 15 percent by weight of the material.
19. The material of claim 18, wherein the absorber concentration is about 10 percent by weight of the material.
20. A process of preparing a material for removing nitrogen oxides, sulfur oxides and carbon monoxide pollutants from combustion exhaust, comprising depositing an oxidation catalyst specie selected from platinum, palladium, rhodium, cobalt, nickel, iron, copper, molybdenum or combination thereof from a solution onto a high surface area support, said support having a surface area of 50 to 350 square meters per gram, and containing alumina, zirconia, titania, silica or a combination of two or more of these oxides;
drying said support and depositing from a solution over said oxidation catalyst specie an absorber material selected from a hydroxide, carbonate or bicarbonate and mixtures thereof of an alkali or alkaline or mixture thereof, said oxidation catalyst specie concentration being 0.05 to 0.6 percent by weight of said material, said absorber disposed on said material at a concentration of 0.5 to 20 percent by weight of the material and drying the support thereby coating said oxidation catalyst specie with said absorber.
drying said support and depositing from a solution over said oxidation catalyst specie an absorber material selected from a hydroxide, carbonate or bicarbonate and mixtures thereof of an alkali or alkaline or mixture thereof, said oxidation catalyst specie concentration being 0.05 to 0.6 percent by weight of said material, said absorber disposed on said material at a concentration of 0.5 to 20 percent by weight of the material and drying the support thereby coating said oxidation catalyst specie with said absorber.
21. The process of claim 20, wherein the oxidation catalyst specie is activated after application.
22. The process of claim 20, wherein the oxidation catalyst specie is dried after application.
23. The process of claim 20, wherein the oxidation catalyst specie is calcined after application and drying.
24. The process of claim 23, wherein the support for the catalyst absorber is a high surface area inorganic material in a shape selected from a sphere, solid cylinder, hollow cylinder, star shape and wheel shape.
25. The process of claim 23, wherein the high surface area support is coated on a metal matrix structure.
26. The process of claim 23, wherein the high surface area support is coated on a ceramic matrix structure.
27. The process of claim 23, wherein the metal matrix structure is coated with a high surface area material and the coating is stabilized by calcining.
28. The process of claim 23, wherein the absorber material is applied to the surface of the stabilized oxidation catalyst specie from solution containing a solvent and the solvent is then removed.
29. The process of claim 23, wherein the absorber is applied to the surface of the stabilized oxidation specie from an aqueous solution and dried.
30. The process according to claim 23, wherein said oxidation catalyst specie comprises platinum.
31. The process according to claim 30, wherein said absorber comprises a carbonate.
32. The process according to claim 31, wherein said absorber comprises an alkali metal carbonate.
33. The material according to claim 1, wherein said high surface area support is coated on a ceramic or metal matrix structure.
34. The material according to claim 33, wherein said ceramic or metal matrix structure comprises a monolith.
35. The material according to claim 34, wherein said matrix structure comprises a metal monolith.
36. The material according to claim 35, wherein said high surface area support comprises alumina.
37. The material according to claim 36, wherein said oxidation catalyst specie comprises Pt and said absorber material comprises carbonate.
38. The material according to claim 1, wherein said absorber coating is contiguous to said oxide catalyst specie.
39. The material according to claim 1, wherein said oxidation catalyst specie is contiguous to said support.
40. A process for removing nitrogen oxides, carbon monoxide and sulfur oxides from a turbine exhaust comprising the steps of:
providing a catalyst absorber in a concentration in the range of 0.5 to 20 percent by weight of said catalyst absorber comprising an alumina support having a surface area of 50 to 350 square meters per gram, a platinum coating on said alumina support and a carbonate salt layer; and contacting said air with said catalyst absorber at a temperature of at least 150 F and not greater than 425 F whereby said nitrogen oxide, carbon monoxide and sulfur oxides are oxidized and then absorbed by said catalyst absorber until said catalyst absorber becomes at least partially saturated, said catalyst absorber disposed on a catalyst specie, said catalyst specie in a concentration of 0.05 to 0.6 percent by weight of said material.
providing a catalyst absorber in a concentration in the range of 0.5 to 20 percent by weight of said catalyst absorber comprising an alumina support having a surface area of 50 to 350 square meters per gram, a platinum coating on said alumina support and a carbonate salt layer; and contacting said air with said catalyst absorber at a temperature of at least 150 F and not greater than 425 F whereby said nitrogen oxide, carbon monoxide and sulfur oxides are oxidized and then absorbed by said catalyst absorber until said catalyst absorber becomes at least partially saturated, said catalyst absorber disposed on a catalyst specie, said catalyst specie in a concentration of 0.05 to 0.6 percent by weight of said material.
41. The process of claim 40, wherein said temperature is in the range of 200 F
to 400 F.
to 400 F.
42. The process of claim 41, wherein said temperature is in the range of 300 F
to 365 F.
to 365 F.
43. The process of claim 40, wherein said platinum is disposed on said catalyst in an amount of about 0.23 weight percent of the weight of the alumina.
44. The process of claim 40, wherein said carbonate is sodium carbonate and is disposed on said catalyst in an amount of about 10.0 weight percent of the weight of the alumina.
45. The process of claim 40, wherein the catalyst absorber is comprised of alumina spheres having a surface area selected from 50 to 350 square meters per gram.
46. The process of claim 40, wherein said catalyst absorber comprises a plurality of alumina spheres disposed in a mesh container.
47. The process of claim 40, wherein said catalyst absorber is regenerated after it is exhausted.
48. The process of claim 40 further comprising the steps of removing the absorber from the gas stream and providing a new absorber when the level of said gaseous pollutants increases to a predetermined level.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/192,003 | 1994-02-04 | ||
| US08/192,003 US5451558A (en) | 1994-02-04 | 1994-02-04 | Process for the reaction and absorption of gaseous air pollutants, apparatus therefor and method of making the same |
| PCT/US1995/001374 WO1995021019A1 (en) | 1994-02-04 | 1995-02-02 | Material for removing contaminants from gaseous stream |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CA2181337A1 CA2181337A1 (en) | 1995-08-10 |
| CA2181337C true CA2181337C (en) | 2006-06-20 |
Family
ID=37392554
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002181337A Expired - Lifetime CA2181337C (en) | 1994-02-04 | 1995-02-02 | Material for removing contaminants from gaseous stream |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2181337C (en) |
-
1995
- 1995-02-02 CA CA002181337A patent/CA2181337C/en not_active Expired - Lifetime
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| Publication number | Publication date |
|---|---|
| CA2181337A1 (en) | 1995-08-10 |
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