GB2035980A - Purifying Waste Gases Containing Nitrous Gases - Google Patents
Purifying Waste Gases Containing Nitrous Gases Download PDFInfo
- Publication number
- GB2035980A GB2035980A GB7937954A GB7937954A GB2035980A GB 2035980 A GB2035980 A GB 2035980A GB 7937954 A GB7937954 A GB 7937954A GB 7937954 A GB7937954 A GB 7937954A GB 2035980 A GB2035980 A GB 2035980A
- Authority
- GB
- United Kingdom
- Prior art keywords
- wash liquid
- permanganate
- manganate
- liquid
- grams
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000007789 gas Substances 0.000 title claims abstract description 20
- 239000002912 waste gas Substances 0.000 title claims abstract description 20
- GQPLMRYTRLFLPF-UHFFFAOYSA-N nitrous oxide Inorganic materials [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 title claims abstract description 13
- 239000007788 liquid Substances 0.000 claims abstract description 60
- LBSANEJBGMCTBH-UHFFFAOYSA-N manganate Chemical compound [O-][Mn]([O-])(=O)=O LBSANEJBGMCTBH-UHFFFAOYSA-N 0.000 claims abstract description 34
- 238000000034 method Methods 0.000 claims abstract description 29
- 238000005406 washing Methods 0.000 claims abstract description 11
- 238000004140 cleaning Methods 0.000 claims abstract description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 21
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 claims description 15
- 238000010521 absorption reaction Methods 0.000 claims description 12
- NUJOXMJBOLGQSY-UHFFFAOYSA-N manganese dioxide Chemical compound O=[Mn]=O NUJOXMJBOLGQSY-UHFFFAOYSA-N 0.000 claims description 10
- 239000003638 chemical reducing agent Substances 0.000 claims description 9
- 238000006243 chemical reaction Methods 0.000 claims description 6
- 229910001385 heavy metal Inorganic materials 0.000 claims description 5
- 150000003839 salts Chemical class 0.000 claims description 4
- DWAQJAXMDSEUJJ-UHFFFAOYSA-M Sodium bisulfite Chemical compound [Na+].OS([O-])=O DWAQJAXMDSEUJJ-UHFFFAOYSA-M 0.000 claims description 3
- 239000004133 Sodium thiosulphate Substances 0.000 claims description 3
- 230000001105 regulatory effect Effects 0.000 claims description 3
- 235000010267 sodium hydrogen sulphite Nutrition 0.000 claims description 3
- 239000004289 sodium hydrogen sulphite Substances 0.000 claims description 3
- AKHNMLFCWUSKQB-UHFFFAOYSA-L sodium thiosulfate Chemical compound [Na+].[Na+].[O-]S([O-])(=O)=S AKHNMLFCWUSKQB-UHFFFAOYSA-L 0.000 claims description 3
- 235000019345 sodium thiosulphate Nutrition 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 claims 1
- 230000001590 oxidative effect Effects 0.000 claims 1
- 238000005554 pickling Methods 0.000 claims 1
- 229910001220 stainless steel Inorganic materials 0.000 claims 1
- 239000010935 stainless steel Substances 0.000 claims 1
- 239000012286 potassium permanganate Substances 0.000 description 5
- 238000012856 packing Methods 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 3
- 229910002651 NO3 Inorganic materials 0.000 description 2
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 2
- 239000003513 alkali Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 230000008929 regeneration Effects 0.000 description 2
- 238000011069 regeneration method Methods 0.000 description 2
- 239000010802 sludge Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 1
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 description 1
- GOPYZMJAIPBUGX-UHFFFAOYSA-N [O-2].[O-2].[Mn+4] Chemical class [O-2].[O-2].[Mn+4] GOPYZMJAIPBUGX-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000010936 aqueous wash Methods 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 229910052748 manganese Inorganic materials 0.000 description 1
- 239000011572 manganese Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002562 thickening agent Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
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
- B01D53/46—Removing components of defined structure
- B01D53/54—Nitrogen compounds
- B01D53/56—Nitrogen oxides
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Environmental & Geological Engineering (AREA)
- Analytical Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Treating Waste Gases (AREA)
- Gas Separation By Absorption (AREA)
Abstract
A method of cleaning waste gases containing nitrous gases, comprises treating the waste gases with a wash liquid containing approximately 0.5 to 60 grams of a manganate VI and approximately 0.5 to 60 grams of a permanganate per litre of the washing liquid while maintaining the pH of the liquid at at least 13.
Description
SPECIFICATION
Purifying Waste Gases Containing Nitrous Gases
The present invention relates to a method of cleaning waste gases containing nitrous gases.
A method is known, in which nitrous gases contained in waste gases are absorbed by washing with an alkaline wash liquid (soda liquor) whereby depending upon the ratio of NO to NO2 in the gas to be absorbed, a mixture of nitrite and nitrate results. The efficiency of absorption of nitrous gases with an alkaline wash liquid is, however, very low when the inlet concentration is low, and has its maximum for a mol-ratio of NO:N02=1 :1. Moreover, pure NO itself is not absorbable in alkaline wash liquid; absorption is only rendered possible by an addition of potassium permanganate to the wash liquid.
Depending upon the pH, the following reactions take place in this method:
a) high alkali concentration NO+MnO4-+2OH7#NO7+MnQ2#+H2O (I)
b) low alkali concentration NO+MnOJ#NO3#+MnO2 (II)
The efficiency of absorption of NO2 is not improved by addition of potassium permanganate. This efficiency is indeed generally made worse, because by adding potassium permanganate NO is preferentially absorbed and thus the mean mol-ratio of NO to NO2 is reduced or changed in an unfavourable direction. Also, considerable operating costs are involved, because potassium permanganate is an expensive oxident.
According to the present invention there is provided a method of cleaning waste gases containing nitrous gases, comprising the steps of treating the waste gases with a wash liquid containing approximately 0.5 to 60 grams of a manganate VI and approximately 0.5 to 60 grams of a permanganate per litre of the washing liquid while maintaining the pH of the liquid at at least 13.
At pH values greater than 13, manganate VI is stable in solution. The following chemical reactions take place in the absorption of nitrous gases in highly alkaline manganate Vl/permanganate wash liquid:
NO2+MnO4-- > NO2-+MnO4- (III) NO+MnO4-+20H- > NO2-+MnO42-+H2O (IV) 2NO+MnO4#2NO2-2NO+MnQ2## (v) Under the aforementioned conditions, the reaction according to equation (V) is of subordinate importance compared to the reaction according to equation (IV). Therefore, on the one hand manganate VI is oxidized by absorption of NO2 to give permanganate, while on the hand permanganate is reduced by absorption of NO to give manganate VI.If, therefore, equal quantities of NO and NO2 are absorbed, no consumption of manganate VI and permanganate takes place and the efficiency of the absorption is simultaneously improved.
If the absorbed quantity of NO2 is greater than the absorbed quantity of NO, permanganate is produced, which can be converted in a simple and inexpensive manner to manganate VI by a reducing agent, for example sodium bisulphite or sodium thiosulphate. At very low crude gas concentrations, it is only necessary to add heavy metal-containing liquid for the catalytic regeneration of manganate VI from permanganate.
If the absorbed quantity of NO is greater than the absorbed quantity of NO2, manganese dioxide is precipitated, which can be separated, dehydrated and converted to manganate VI. The extra costs for the chemicals, such as potassium permanganate and reducing agent, are more than compensated by the low costs of investment and energy. The efficiency of the method can be regulated by adding salts to the wash liquid and by the relative concentrations of manganate VI and permanganate. The efficiency of the process is considerably improved with a slightly increased consumption of chemicals.
This means that the method can be adapted to a change bf the crude gas conditions.
The invention will now be described by way of example and with reference to the accompanying drawing in which:
Fig. 1 shows a single-stage washing plant, and
Fig. 2 shows a two-stage washing plant.
The single-stage washing plant shown in Fig. 1 of the drawing comprises a washer 1 comprising at its lower region a collecting chamber 2 for the wash, liquid. Above this collecting chamber 2 a pipe 3 leads into the washer 1, through which pipe the waste gas to be purified flows into the washer 1.
Through a pipe 4, which is disposed in the upper region of the washer 1 , the purified gas leaves the washer 1. Between the inlet pipe 3 and outlet pipe 4, known packing objects or units 5 (not shown in more detail) are provided in the washer 1 and over these is disposed a sprinkling device 6. The packing objects 5 are sprinkled with the wash liquid pumped through the sprinkling device 6 by a pump 7 disposed in a pipe extending between the collecting chamber 2 and the sprinkling device 6, while the waste gas flows from the bottom upwards through the packing objects 5. The nitrous gases (NO, NO2) contained in the waste gas are here washed out and absorbed by the wash liquid.
The so-called aqueous wash liquid situated in the collecting chamber 2 of the washer 1 and serving for absorbing the nitrous gases contains 15 grams of manganate VI and 1 5 grams of permanganate per litre of wash liquid and is continually maintained at a pH of at least 13. For maintaining this pH value, sodium hydroxide and/or potassium hydroxide liquor is added in a controlled manner to the wash liquid from a storage tank 8. In the collecting chamber 2 of the washer 1, a pH measuring device 9 is disposed which, if the pH value falls below 1 3, temporarily opens an outlet valve
11 mounted in a line 10 between the tank 8 and the washer 1, so that the sodium hydroxide and/or potassium hydroxide liquor can flow from the tank 8 into the collecting chamber 2 of the washer 1.
For maintaining the desired summated concentration of manganese VI and permanganate, wash liquid is continually drawn off from the collecting chamber 2 of the washer 1 through a line 13 by a pump 12 and is recycled through a process photometer 14 back to the washer 1. In the process photometer 14, the extinction is measured at a wavelength of 465 nM or 575 nM. According to the reading obtained, the temporary opening of an outlet valve 1 5, which is incorporated in a line 16 between a storage tank 17 and the washer 1 is controlled. The storage tank 17 contains manganate VI and permanganate.
As a result of the highly alkaline manganate Vl/permanganate wash liquid, manganate VI is oxidized by absorption of NO2 to permanganate (III) in the washer 1, while permanganate is reduced by absorption of NO to manganate VI (IV). If, therefore, equal quantities of NO and NO2 are absorbed, no consumption of manganate VI and permanganate takes place. If the absorbed quantity of NO2 exceeds the absorbed quantity of NO, permanganate is produced, which can be converted by the addition of a reducing agent to manganate VI. In the collecting chamber 2 of the washer 1, a redox measuring device 18 is provided, by which the ratio of manganate VI to permanganate is measured.If the proportion of permanganate increases, then with control via the redox measuring device 18 an outlet valve 1 9 which is incorporated in a line 20 between the tank 21 and the washer 1, is temporarily opened. The tank 21 contains a reducing agent, for example sodium bisulphite or sodium thiosulphate.
The two-stage washing plant shown in Fig. 2 comprises a prewasher 22 and a main washer 23, which are constructed in the same manner as the washer 1 shown in Fig. 1 and each comprises packing objects or units, a sprinkler device, a circulating pump and a collecting chamber for the wash liquid. Waste gas which contains nitrous gases flows through a line 24 into the prewasher 1 and leaves this prewasher through a line 25 leading to the main washer 23. The purified waste gas leaves the main washer 23 through a line 26.
The wash liquid present in the main washer 23 has the same composition as the wash liquid of the single-stage washing plant. Associated with this main washer 23 is a tank 27, which contains a prepared solution of manganate VI, permanganate and sodium hydroxide liquor, which is added to the washing liquid in a controlled manner via a level switch 28. By adding a reducing agent from a tank 29, controlled by a redox measuring device, the ratio of manganate VI to permanganate is maintained constant-in the same manner as in the single-stage washing plant.
The wash liquid in the prewasher 22 contains, when the plant is started up, only sodium
hydroxide as an additive in order to achieve a pH value between 7 and 13. For the purpose of after
metering and for maintaining this pH value constant a pump 30 is temporarily switched on with control via a pH measuring device 30a, causing wash liquid to be supplied from the main washer 23 into the
prewasher 22. As a result the wash liquid in the prewasher additionally receives small quantities of
manganate VI and permanganate. Furthermore, in the collecting chamber of the prewasher 22 a
conductivity measuring device 31 is mounted, by which the salt content of the wash liquid is measured
and, when required, the addition of water is effected in a controlled manner through a line 32.By
means of the prewash with alkaline wash liquid, the consumption of manganate VI and permanganate
in the main washer 23 is reduced.
The manganese dioxide (pyrolusite) sludge produced in the prewasher 22 is drawn off at the
bottom and passed through a thickener 33 and a filter press 34. The thus dehydrated manganese
dioxide sludge is then oxidized in a regeneration device 35 to produce manganate VI.
The table below gives the purification performance of a single-stage laboratory plant with a
packed depth of 1800 millimetres and a gas flow speed of 1 metre per second-in relation to the free
cross-section-whereby the wash liquid A contains only 50 grams of soda liquor per litre of waste
liquid A, whereas in the wash liquid B, in addition to 50 grams of soda liquor per litre of waste liquid B,
there is also 1 5 grams of manganate VI per litre of waste liquid B and 1 5 grams of permanganate per
litre of waste liquid B.
Crude gas
concentration Purified Gas Concentration (ppm) (pump Wash with A Wash with B
NO NO2 NO NO, NO NO, 150 450 112 328 90 99
300 1.700 210 986 45 370
300 300 240 177 234 62
1.000 1.000 700 570 140 225
This table also shows that the absorption efficiencies in respect of NO and NO2 is not dependent upon the summated concentration of the nitrous gases.
Claims (1)
- Claims1. A method of cleaning waste gases containing nitrous gases, comprising the steps of treating the waste gases with a wash liquid containing approximately 0.5 to 60 grams of a manganate VI and approximately 0.5 to 60 grams of a permanganate per litre of the washing liquid while maintaining the pH of the liquid at at least 13.2. A method as claimed in claim 1, wherein the wash liquid contains substantially 15 grams of the manganate VI and substantially 1 5 grams of the permanganate per litre of wash liquid.3. A method as claimed in claim 1, wherein the wash liquid contains at least 10 grams of at least one of sodium hydroxide and potassium hydroxide per litre of wash liquid.4. A method as claimed in claim 3, wherein the wash liquid contains 20 to 100 grams of at least one of sodium hydroxide and potassium hydroxide per litre of wash liquid.5. A method as claimed in any one of the preceding claims, comprising the step of controlling the alkalinity of the wash liquid with the aid of a pH measuring device.6. A method as claimed in any one of the preceding claims, wherein the wash liquid contains small quantities of heavy metal salts.7. A method according to claim 6, wherein the heavy metal salts are provided by 0.1 to 1.0% a heavy metal containing liquid.8. A method as claimed in claim 7, wherein the heavy metal containing liquid comprises a stainless steel pickling liquid.9. A method as claimed in any one of the preceding claims, comprising the step of metering a reducing agent to the wash liquid to maintain the ratio of manganate VI to permanganate constant.10. A method as claimed in claim 8, wherein the reducing agent comprises at least one of sodium bisulphite and sodium thiosulphate.11. A method as claimed in either claim 9 or claim 10, comprising the step of regulating the metering of the reducing agent with the aid of redox potential means.12. A method as claimed in either claim 9 or claim 10, comprising the step of regulating the metering of the reducing agent with the aid of photometer means.13. A method as claimed in any one of claims 9 to 12, comprising the step of measuring the summation concentration of manganate VI and permanganate by photometer means and maintaining the concentration constant by metering of manganate VI and permanganate.14. A method as claimed in any one of the preceding claims, comprising the step of prewashing the waste gas with alkaline wash liquid prior to the treating step.15. A method as claimed in claim 14, comprising the step of metering wash liquid used in the treating step to the liquid used in the prewashing step to maintain the pH of the liquid used in the prewashing step between 7 and 13.16. A method as claimed in either claim 14 or claim 15, wherein manganese dioxide is produced in the prewashing step and manganate VI is produced therefrom by the steps of separating and dehydrating and the further step of oxidizing with at least one of sodium hydroxide and potassium hydroxide.17. A method of cleaning waste gases as claimed in any one of claims 1 to 13 and substantially as hereinbefore described with reference to Fig. 1 of the accompanying drawing.1 8. A method of cleaning waste gases as claimed in any one of claims 14 to 16 and substantially as hereinbefore described with reference to Fig. 2 of the accompanying drawing.New Claims or Amendments to Claims filed on 28th March 1980 Superseded Claims 1 New or Amended Claims:~1. A method of cleaning waste gases containing NO and NO2, comprising the steps of treating the waste gases with a wash liquid containing approximately 0.5 to 60 grams of permanganate per litre of the wash liquid thereby to cause manganate VI to form by reduction of the permanganate through absorption of NO, adding reducing means to maintain the pH of the wash liquid to be at least 13 and, by reaction with the permanganate, to cause the wash liquid to constantly contain 0.5 to 60 grams of manganate VI per litre of the wash liquid, and converting manganate VI, which has been produced by said reduction of or reaction with permanganate, back to permanganate through absorption of NO2.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2847920A DE2847920C2 (en) | 1978-11-04 | 1978-11-04 | Process for cleaning exhaust gases containing nitrous |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2035980A true GB2035980A (en) | 1980-06-25 |
| GB2035980B GB2035980B (en) | 1982-11-17 |
Family
ID=6053886
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB7937954A Expired GB2035980B (en) | 1978-11-04 | 1979-11-01 | Purifying waste gases containing nitrous gases |
Country Status (7)
| Country | Link |
|---|---|
| AT (1) | AT374376B (en) |
| BE (1) | BE879634A (en) |
| DE (1) | DE2847920C2 (en) |
| FR (1) | FR2465513A1 (en) |
| GB (1) | GB2035980B (en) |
| IT (1) | IT1125606B (en) |
| SE (1) | SE438267B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT383049B (en) * | 1985-01-28 | 1987-05-11 | Elin Union Ag | METHOD FOR REDUCING THE EMISSION VALUES OF INDUSTRIAL EXHAUST GASES AND INDUSTRIAL EXHAUST |
| US5083579A (en) * | 1988-07-15 | 1992-01-28 | Vanin Anatoly F | Composition for absorbing nitrogen oxide from tobacco smoke, method for absorbing nitrogen oxide using said composition, filter for purifying tobacco smoke using said composition, and method for impregnating the base of a filter with said composition |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3334196A1 (en) * | 1983-09-22 | 1985-04-11 | Uhde Gmbh, 4600 Dortmund | Process for reducing the SO2 content in flue gases |
| DE3583409D1 (en) * | 1984-04-11 | 1991-08-14 | Isola Werke Ag | METHOD FOR THE PRODUCTION OF MULTILAYERED LAYER COMPRESSION MATERIALS AND THE LAYER PRESSURE MATERIALS OBTAINED THEREOF. |
| SE462702B (en) * | 1988-03-17 | 1990-08-20 | Armerade Plastprodukter | PROCEDURES FOR THE REMOVAL OF EASY ORGANIC ORGANIC SOCIETY FROM AIR |
| NL8902490A (en) * | 1989-10-06 | 1991-05-01 | Leonardus Mathijs Marie Nevels | METHOD FOR CLEANING FLUE GASES |
-
1978
- 1978-11-04 DE DE2847920A patent/DE2847920C2/en not_active Expired
-
1979
- 1979-10-11 AT AT0661779A patent/AT374376B/en active
- 1979-10-25 BE BE0/197822A patent/BE879634A/en not_active IP Right Cessation
- 1979-11-01 SE SE7909055A patent/SE438267B/en not_active IP Right Cessation
- 1979-11-01 GB GB7937954A patent/GB2035980B/en not_active Expired
- 1979-11-02 IT IT27030/79A patent/IT1125606B/en active
- 1979-11-05 FR FR7927521A patent/FR2465513A1/en active Granted
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AT383049B (en) * | 1985-01-28 | 1987-05-11 | Elin Union Ag | METHOD FOR REDUCING THE EMISSION VALUES OF INDUSTRIAL EXHAUST GASES AND INDUSTRIAL EXHAUST |
| US5083579A (en) * | 1988-07-15 | 1992-01-28 | Vanin Anatoly F | Composition for absorbing nitrogen oxide from tobacco smoke, method for absorbing nitrogen oxide using said composition, filter for purifying tobacco smoke using said composition, and method for impregnating the base of a filter with said composition |
Also Published As
| Publication number | Publication date |
|---|---|
| AT374376B (en) | 1984-04-10 |
| DE2847920A1 (en) | 1980-05-08 |
| SE438267B (en) | 1985-04-15 |
| FR2465513B3 (en) | 1982-07-16 |
| SE7909055L (en) | 1980-05-05 |
| FR2465513A1 (en) | 1981-03-27 |
| BE879634A (en) | 1980-02-15 |
| DE2847920C2 (en) | 1984-05-17 |
| ATA661779A (en) | 1983-09-15 |
| IT7927030A0 (en) | 1979-11-02 |
| IT1125606B (en) | 1986-05-14 |
| GB2035980B (en) | 1982-11-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4670234A (en) | Process for stripping nitrogen oxides and sulphur oxides as well as optionally other noxious elements of flue gas from combustion plants | |
| CN102580496B (en) | Liquid-phase oxidation multistage absorbed flue gas desulfurization and denitrification technology and device | |
| US4009251A (en) | Process for the removal of hydrogen sulfide from gaseous streams by catalytic oxidation of hydrogen sulfide to sulfur while inhibiting the formation of sulfur oxides | |
| US3985860A (en) | Method for oxidation of SO2 scrubber sludge | |
| US4311680A (en) | Method for removal of sulfur compounds from a gas stream | |
| RU2573677C2 (en) | Device and method for gas flow cleaning | |
| US3991167A (en) | Process for lowering nitrogen oxides in effluent gases | |
| US7455820B2 (en) | Process for removing sulfur dioxide and nitrogen oxides from flue gas using chlorine dioxide | |
| US4222993A (en) | Removal of noxious contaminants from gas | |
| GB2035980A (en) | Purifying Waste Gases Containing Nitrous Gases | |
| CN1194176A (en) | New technology for absorbing and eliminating sulfur dioxide in smoke chemically | |
| CA2064724A1 (en) | Process for the removal of hydrogensulphide (h2s) from biogas | |
| JPS6336818B2 (en) | ||
| CN105032173A (en) | Device and process of ammonia-soda-process combined desulfurization and denitrification | |
| CN111330442B (en) | Ammonia process catalysis combined desulfurization and denitrification method | |
| CN106215626A (en) | A kind of high atomization flue gas desulfurization processing method | |
| US4400361A (en) | Method of removing H2 S from a gas stream utilizing boron-vanadium and iron complexes | |
| KR100481760B1 (en) | Process for removing selenium from a selenium-containing liquid | |
| CN108854490B (en) | Chloroacetic acid tail gas purification and byproduct hydrochloric acid desulfurization process | |
| CN104190227A (en) | Wet flue gas ammonia desulfurization-based synchronous denitration system | |
| CN204502800U (en) | A kind of ammonia-soda process combined desulfurization and denitration device | |
| US4086324A (en) | Removal of sulfur and nitrogen oxides with aqueous absorbent | |
| US4178348A (en) | Process for removing sulfur oxides in exhaust gases | |
| DE69912005T2 (en) | METHOD FOR CONVERTING SULFUR HYDROGEN TO ELEMENTAL SULFUR | |
| CN206549359U (en) | A kind of incinerator gas washing and Waste Water Treatment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |