CA1295814C - Method of purifying flue or exhaust gases - Google Patents
Method of purifying flue or exhaust gasesInfo
- Publication number
- CA1295814C CA1295814C CA000520131A CA520131A CA1295814C CA 1295814 C CA1295814 C CA 1295814C CA 000520131 A CA000520131 A CA 000520131A CA 520131 A CA520131 A CA 520131A CA 1295814 C CA1295814 C CA 1295814C
- Authority
- CA
- Canada
- Prior art keywords
- catalyst
- gases
- liquid
- purifying method
- contact liquid
- 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
Links
Classifications
-
- 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
-
- 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
- B01D53/8643—Removing mixtures of carbon monoxide or hydrocarbons and nitrogen oxides
- B01D53/8646—Simultaneous elimination of the components
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Catalysts (AREA)
- Exhaust Gas Treatment By Means Of Catalyst (AREA)
- Hydrogen, Water And Hydrids (AREA)
- Treating Waste Gases (AREA)
- Separation Of Gases By Adsorption (AREA)
- Silicon Compounds (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of purifying an exhaust or flue gas by removing environmentally noxious gases therefrom, which comprises the steps of intensively mixing the gases with a contact liquid containing a catalyst until the gases and liquid have formed a foam, and reacting the gases with the catalyst in the formed foam.
A method of purifying an exhaust or flue gas by removing environmentally noxious gases therefrom, which comprises the steps of intensively mixing the gases with a contact liquid containing a catalyst until the gases and liquid have formed a foam, and reacting the gases with the catalyst in the formed foam.
Description
\ ~z~
The present invention relates to improvements ln the purificatlon of an exhaust or flue gas by removing environmentally noxious gases therefrom, for example as are present in flue gases developed during the productlon of nitric acid or in exhaust gases from internal combustion engines, including nitrogen oxides, carbon monoxide, hydrocarbons and/or sulfur oxides.
It is known to remove such environmentally noxious gases as nitrogen oxides in the gaseous phase by means of catalysts and additional substances, for example ammonia. Gas purification installations ~or carrying out such processes are very expensive to build. In addition, the efectiveness of the cata}y~ts used in th~se methods i8 llmited 80 that they must be regenerated every two years, at the latest, to obtain satisfactory results.
It is an object of this invention to overcome these disadvantages and to remove 9D-99~ of the environmentally noxious gases present in flue or exhaust gases, such as oxldes of nitrogen and sulfur, hydrocarbons and carbon monoxide, in a ; single stage.
We accomplish this and other objects in accordance with the ~: :
I inventlon by intensively mixing the gases with a contact 11quid containing a catalyst suspended or dissolved in the llquid I until the gases and liquid have formed a foamt and reactin~ the ~ gase~ with the catalyst in the for~ed foam.
.
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Useful catalysts include, for example, lnorganic catalysts, such as Raney nickel or platinum black, or organic catalysts, ~uch as metallic phthalocyanine whose metalllc ato~ is, for example, copper, iron or cobalt. These catalysts, for example platinum black or phthalocyanine, are suspended in a carrier liquid or, for example phthalocyaninesulfonate, are dissolved therein.
Useful carrler liquids for the catalysts include, for example, silicon oils and paraffin olls as well as other chemically inert liquids, such as quinoline, trlch:Lorobenzene or benzophenonone.
If the contact liquid iæ an aqueous catalyst solution, the gases are reacted with the catalyst at a temperature of 20C to 150C, preferably 90-100C. If the contact liquid has a hl~h botling point, the gases are xeacted at a temperature of 20C
to 250C, or up to 500C if the gases are removed from the exhaust gas of an internal combustion engine.
According to a preferred feature of the present invention, the contact liquld ls fed downwardly and countercurrently to the foam phase, a partial stream is branched off, the partial tream is optionally passed through a heat exchanger and is then tested for ~ensity of the catalyst contalned t~lerein, and an amount of catalyst r~quired to attain a desired level of catalyst denslty i8 added to the stream.
The present invention relates to improvements ln the purificatlon of an exhaust or flue gas by removing environmentally noxious gases therefrom, for example as are present in flue gases developed during the productlon of nitric acid or in exhaust gases from internal combustion engines, including nitrogen oxides, carbon monoxide, hydrocarbons and/or sulfur oxides.
It is known to remove such environmentally noxious gases as nitrogen oxides in the gaseous phase by means of catalysts and additional substances, for example ammonia. Gas purification installations ~or carrying out such processes are very expensive to build. In addition, the efectiveness of the cata}y~ts used in th~se methods i8 llmited 80 that they must be regenerated every two years, at the latest, to obtain satisfactory results.
It is an object of this invention to overcome these disadvantages and to remove 9D-99~ of the environmentally noxious gases present in flue or exhaust gases, such as oxldes of nitrogen and sulfur, hydrocarbons and carbon monoxide, in a ; single stage.
We accomplish this and other objects in accordance with the ~: :
I inventlon by intensively mixing the gases with a contact 11quid containing a catalyst suspended or dissolved in the llquid I until the gases and liquid have formed a foamt and reactin~ the ~ gase~ with the catalyst in the for~ed foam.
.
~ ': ' ~
~ :.
.
~2g5~
Useful catalysts include, for example, lnorganic catalysts, such as Raney nickel or platinum black, or organic catalysts, ~uch as metallic phthalocyanine whose metalllc ato~ is, for example, copper, iron or cobalt. These catalysts, for example platinum black or phthalocyanine, are suspended in a carrier liquid or, for example phthalocyaninesulfonate, are dissolved therein.
Useful carrler liquids for the catalysts include, for example, silicon oils and paraffin olls as well as other chemically inert liquids, such as quinoline, trlch:Lorobenzene or benzophenonone.
If the contact liquid iæ an aqueous catalyst solution, the gases are reacted with the catalyst at a temperature of 20C to 150C, preferably 90-100C. If the contact liquid has a hl~h botling point, the gases are xeacted at a temperature of 20C
to 250C, or up to 500C if the gases are removed from the exhaust gas of an internal combustion engine.
According to a preferred feature of the present invention, the contact liquld ls fed downwardly and countercurrently to the foam phase, a partial stream is branched off, the partial tream is optionally passed through a heat exchanger and is then tested for ~ensity of the catalyst contalned t~lerein, and an amount of catalyst r~quired to attain a desired level of catalyst denslty i8 added to the stream.
:: ' ', . .
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If oxides of nitrogen are removed fro~ the flue or exhaust gas, a subst~ate reactive therewith, for example ammonia, carbon monoxide or hydrocarbons, may be added in stoichiometric amounts.
The maintenance of an intensive gas-liquid phase contact at the lowest pressure loss possible enables the method of this invention to be carried out on an industrial scale. This effect may be achieved, for example, ln a column comprising phase contact bottoms which ald in overcoming and controlling the hydrostatic pressure oE the liquid column resting thereon.
Such an apparatus i9 disclosed ln European patent application publication No. 73,801, published March 16, 19~3.
_ It i9 known to use metallio phthalocyanines as catalysts for hydrating carbon monoxide to a Cl - C5 hydrocarbon, and to use cobalt or iron phthalocyanine on coal for the removal of oxides o~ nitrogen from cigarette smoke. It is, however, surprislng to ~ind such catalysts and others suqpended or dissolved in a carrier llquid to have a great effect in intensive phase contact with the ga3eous mixtures to be purified.
~ .
This helghtened activity of the catalyst~ is of : ~
coneiderable technical lmportan~e. For example, a 90-e~ficiency can be obtained with powe~ plant exhaust gases ;~ ~ containing about 1000 ppm of oxides of ni~rogen, ~reated with iron phthalocyanine at a temperature of 150C ~y using about 10 ~; -3-, ~
.
-~z~
phase contact boktoms, an increase of the number of contact bottoms increasing this efficiency up to 99~. When using a circulating amount of 200 1 carrier liquid, 10 kg of catalyst are needed.
The above and other ob~ects, advantages and features of the invention will be more fully described in connection wlth the following preferred embodiments taken in conjunction with the accompanying schematic drawing of apparatus useful for carrying out the method and wherein FIG. 1 shows an installation using ammonia a~ a reactlon ~ubstrate and FIG. 2 shows an installation converting the removed oxides of nitrogen to ammonium nitrate.
Referring now to the drawing and first to FIG. 1, du~t and sulfur are first removed from the flue gas to be purified by contacting the flue gas with an ammoniacal solutiQn before ~t i~ introduced in~o mixing chamber M. Ammonla is stoichiometrically admixed to the flue gas in the ~ixing chamber under the control of a measuring probe. The catalyst suspended or-dls~olved in a carrier llquid, for example water, paraffin or si~icon oil, is ¢irculated in reaction chamber R, and is countercurrently brought into intensive phase contact with the rising gas by means of ouitable contac~ element~ to form a foam. In thl~ foam phase1 the o~ides of nltrogen react with the add ~3 to generate nitrogen nd water.
~zg~
Residual catalyst is removed from the purified flue gas with cleaned carrier liquid in gas scrubber W ~nd returned to reaction chamber R. Sludge is removed from the reaction column at the bottom thereof.
The concentration of the catalyst is about 1 to 30~, by weight, of the carrier liquid, preferably about 5~. Depending on the catalyst, the treatment temperature is in the range of 20C to 5Q0C, preferably about 20-150C.
FIG. 2 shows a like reaction tower u~ed for the production of ammonium nitrate from the removed oxides of nitrogen. In this embodiment, the NH3 is not lntroduced into reaction chamber R but lnto the gas scrubber W.
_ If exhaust gases from stationary Diesel motors are to be purified, no dust and sulfur need be removed therefrom before they are treated.
;, In the purlfication method of the pre~ent invention, the degree of removal of nitrogen oxides from flue or exhaust gases containing up to 10,000 ppm NOX is above 90%.
Consldering increased CO contents ln Diesel motor exhaust ;gases, it ls posslb~e to purify the exhaust gases from Diesel motor trucks with the use of CO as a reaction substrate, CO
being reacted to generate CO2 and the hydrocarbons being reacted to generate CO2 and H2O.
: ~ ~:: ~ : :
, ~:;
~, ~,: .
~' ~5~
.
: . , : .
" - , ,' ,, . , :
' ' ,~
1%~i8~4~
If oxides of nitrogen are removed fro~ the flue or exhaust gas, a subst~ate reactive therewith, for example ammonia, carbon monoxide or hydrocarbons, may be added in stoichiometric amounts.
The maintenance of an intensive gas-liquid phase contact at the lowest pressure loss possible enables the method of this invention to be carried out on an industrial scale. This effect may be achieved, for example, ln a column comprising phase contact bottoms which ald in overcoming and controlling the hydrostatic pressure oE the liquid column resting thereon.
Such an apparatus i9 disclosed ln European patent application publication No. 73,801, published March 16, 19~3.
_ It i9 known to use metallio phthalocyanines as catalysts for hydrating carbon monoxide to a Cl - C5 hydrocarbon, and to use cobalt or iron phthalocyanine on coal for the removal of oxides o~ nitrogen from cigarette smoke. It is, however, surprislng to ~ind such catalysts and others suqpended or dissolved in a carrier llquid to have a great effect in intensive phase contact with the ga3eous mixtures to be purified.
~ .
This helghtened activity of the catalyst~ is of : ~
coneiderable technical lmportan~e. For example, a 90-e~ficiency can be obtained with powe~ plant exhaust gases ;~ ~ containing about 1000 ppm of oxides of ni~rogen, ~reated with iron phthalocyanine at a temperature of 150C ~y using about 10 ~; -3-, ~
.
-~z~
phase contact boktoms, an increase of the number of contact bottoms increasing this efficiency up to 99~. When using a circulating amount of 200 1 carrier liquid, 10 kg of catalyst are needed.
The above and other ob~ects, advantages and features of the invention will be more fully described in connection wlth the following preferred embodiments taken in conjunction with the accompanying schematic drawing of apparatus useful for carrying out the method and wherein FIG. 1 shows an installation using ammonia a~ a reactlon ~ubstrate and FIG. 2 shows an installation converting the removed oxides of nitrogen to ammonium nitrate.
Referring now to the drawing and first to FIG. 1, du~t and sulfur are first removed from the flue gas to be purified by contacting the flue gas with an ammoniacal solutiQn before ~t i~ introduced in~o mixing chamber M. Ammonla is stoichiometrically admixed to the flue gas in the ~ixing chamber under the control of a measuring probe. The catalyst suspended or-dls~olved in a carrier llquid, for example water, paraffin or si~icon oil, is ¢irculated in reaction chamber R, and is countercurrently brought into intensive phase contact with the rising gas by means of ouitable contac~ element~ to form a foam. In thl~ foam phase1 the o~ides of nltrogen react with the add ~3 to generate nitrogen nd water.
~zg~
Residual catalyst is removed from the purified flue gas with cleaned carrier liquid in gas scrubber W ~nd returned to reaction chamber R. Sludge is removed from the reaction column at the bottom thereof.
The concentration of the catalyst is about 1 to 30~, by weight, of the carrier liquid, preferably about 5~. Depending on the catalyst, the treatment temperature is in the range of 20C to 5Q0C, preferably about 20-150C.
FIG. 2 shows a like reaction tower u~ed for the production of ammonium nitrate from the removed oxides of nitrogen. In this embodiment, the NH3 is not lntroduced into reaction chamber R but lnto the gas scrubber W.
_ If exhaust gases from stationary Diesel motors are to be purified, no dust and sulfur need be removed therefrom before they are treated.
;, In the purlfication method of the pre~ent invention, the degree of removal of nitrogen oxides from flue or exhaust gases containing up to 10,000 ppm NOX is above 90%.
Consldering increased CO contents ln Diesel motor exhaust ;gases, it ls posslb~e to purify the exhaust gases from Diesel motor trucks with the use of CO as a reaction substrate, CO
being reacted to generate CO2 and the hydrocarbons being reacted to generate CO2 and H2O.
: ~ ~:: ~ : :
, ~:;
~, ~,: .
~' ~5~
.
: . , : .
" - , ,' ,, . , :
' ' ,~
Claims (10)
1. A method of purifying an exhaust or flue gas by removing environmentally noxious gases therefrom, which comprises the steps of (a) intensively mixing the gases with a contact liquid containing a catalyst until the gases and liquid have formed a foam, and (b) reacting the gases with the catalyst in the formed foam.
2. The purifying method of claim 1, wherein the catalyst is suspended in the contact liquid.
3. The purifying method of claim 1, wherein the catalyst is dissolved in the contact liquid.
4, The purifying method of claim 1, wherein the foam is formed in a column comprising phase contact bottoms and the gases are fed through the column countercurrently to the contact liquid.
5. The purifiying method of claim 1, wherein the contact liquid is an aqueous catalyst solution and the gases are reacted with the catalyst at a temperature of 20° to 150°C.
6. The purifying method of claim 5, wherein the temperature is 90° to 100°C.
7. The purifying method of claim 1, wherein the contact liquid is a liquid having a high boiling point and the gases are reacted with the catalyst at a temperature of 20° to 250°C.
8. The purifying method of claim 1, wherein the contact liquid is a liquid having a high boiling point, the gases are in the exhaust gas of an internal combustion engine and the gases are reacted with the catalyst at a temperature of 20° to 500°C.
9. The purifying method of claim 1, wherein the contact liquid is fed downwardly and countercurrently to the foam, a partial stream is branched off, the partial stream is tested for density of the catalyst contained therein and an amount of catalyst required to attain a desired level of catalyst density is added to the stream.
10. The purifying method of claim 9, wherein the partial stream is passed through a heat exchanger before being tested.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ATA2906/85 | 1985-10-08 | ||
| AT0290685A AT383287B (en) | 1985-10-08 | 1985-10-08 | METHOD FOR PURIFYING GAS MIXTURES |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1295814C true CA1295814C (en) | 1992-02-18 |
Family
ID=3542188
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000520131A Expired - Lifetime CA1295814C (en) | 1985-10-08 | 1986-10-08 | Method of purifying flue or exhaust gases |
Country Status (9)
| Country | Link |
|---|---|
| EP (1) | EP0218574B1 (en) |
| AT (2) | AT383287B (en) |
| CA (1) | CA1295814C (en) |
| CZ (1) | CZ726086A3 (en) |
| DD (1) | DD250059A5 (en) |
| DE (1) | DE3681110D1 (en) |
| HU (1) | HUT43966A (en) |
| PL (1) | PL261739A1 (en) |
| ZA (1) | ZA867272B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3835161C2 (en) * | 1988-10-13 | 1996-08-14 | Werner Dipl Chem Fabian | Exhaust gas purification using catalytic oxidation with atmospheric oxygen |
| US5910291A (en) * | 1992-03-16 | 1999-06-08 | Envirosurgical, Inc. | Surgery plume filter device and method of filtering |
| US5288469A (en) * | 1992-03-16 | 1994-02-22 | Envirosurgical, Inc. | Surgery plume filter device |
| AU4102493A (en) * | 1992-03-16 | 1994-11-08 | Envirosurgical, Inc. | Surgery plume filter device and method of filtering |
| FR2701220B1 (en) * | 1993-02-08 | 1995-04-14 | Inst Francais Du Petrole | Process for catalytic deodorization and reduction of the nitrogen content of slurry tank effluents. |
| CN116832873B (en) * | 2023-07-25 | 2024-02-27 | 西北大学 | Complex iron catalyst for removing hydrogen sulfide in industrial gas and preparation method thereof |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2385200A (en) * | 1942-06-25 | 1945-09-18 | Hooker Electrochemical Co | Methods and apparatus for reacting gases with liquids |
| BE765087A (en) * | 1970-04-20 | 1971-08-16 | Becker Raymond O | METHOD AND APPARATUS AGAINST ATMOSPHERIC AIR POLLUTION |
| CS160060B2 (en) * | 1971-07-21 | 1975-02-28 | ||
| JPS5643771B2 (en) * | 1973-12-18 | 1981-10-15 | ||
| FR2382923A1 (en) * | 1977-02-28 | 1978-10-06 | Percevaut Emile | Gas purifier, esp. for diesel engine exhaust gases - incorporates washer, decantation tank and wash-liquor treatment chamber, forming autonomous closed circuit unit |
| CA1075879A (en) * | 1977-05-04 | 1980-04-22 | Gulf Canada Limited | Recovery of sulfur from gas streams containing sulfur and sulfur compounds in dilute concentration |
| DE2736488C3 (en) * | 1977-08-12 | 1980-03-13 | Steag Ag, 4300 Essen | Process for removing sulfur oxides from flue gases |
| US4238462A (en) * | 1978-01-31 | 1980-12-09 | Air Resources, Inc. | Autocirculation process and apparatus |
| US4325923A (en) * | 1978-07-26 | 1982-04-20 | Rhone-Poulenc Industries | Contacting of plural phases |
| US4374104A (en) * | 1980-09-30 | 1983-02-15 | Air Resources, Inc. | Composition and method for removing hydrogen sulfide from gas stream |
| DE3108075A1 (en) * | 1981-03-04 | 1982-09-16 | Basf Ag, 6700 Ludwigshafen | METHOD FOR REMOVING DISTICKOXIDE OXIDE FROM SUCH CONTAINING EXHAUST GASES |
-
1985
- 1985-10-08 AT AT0290685A patent/AT383287B/en not_active IP Right Cessation
-
1986
- 1986-09-24 ZA ZA867272A patent/ZA867272B/en unknown
- 1986-10-06 DD DD86295071A patent/DD250059A5/en unknown
- 1986-10-06 PL PL1986261739A patent/PL261739A1/en unknown
- 1986-10-07 EP EP86890275A patent/EP0218574B1/en not_active Expired - Lifetime
- 1986-10-07 HU HU864200A patent/HUT43966A/en unknown
- 1986-10-07 AT AT86890275T patent/ATE66632T1/en not_active IP Right Cessation
- 1986-10-07 CZ CS867260A patent/CZ726086A3/en unknown
- 1986-10-07 DE DE8686890275T patent/DE3681110D1/en not_active Expired - Fee Related
- 1986-10-08 CA CA000520131A patent/CA1295814C/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| AT383287B (en) | 1987-06-10 |
| DD250059A5 (en) | 1987-09-30 |
| ZA867272B (en) | 1987-05-27 |
| EP0218574B1 (en) | 1991-08-28 |
| DE3681110D1 (en) | 1991-10-02 |
| CZ726086A3 (en) | 1995-06-14 |
| PL261739A1 (en) | 1988-05-26 |
| EP0218574A2 (en) | 1987-04-15 |
| HUT43966A (en) | 1988-01-28 |
| ATE66632T1 (en) | 1991-09-15 |
| ATA290685A (en) | 1986-11-15 |
| EP0218574A3 (en) | 1989-03-08 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |