CA2266492A1 - Method for reducing emissions of detrimental nitrogen compounds - Google Patents
Method for reducing emissions of detrimental nitrogen compounds Download PDFInfo
- Publication number
- CA2266492A1 CA2266492A1 CA002266492A CA2266492A CA2266492A1 CA 2266492 A1 CA2266492 A1 CA 2266492A1 CA 002266492 A CA002266492 A CA 002266492A CA 2266492 A CA2266492 A CA 2266492A CA 2266492 A1 CA2266492 A1 CA 2266492A1
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- CA
- Canada
- Prior art keywords
- boiler
- supplied
- vent gases
- furnace
- nitrogen
- 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.)
- Abandoned
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Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
- D21C11/06—Treatment of pulp gases; Recovery of the heat content of the gases; Treatment of gases arising from various sources in pulp and paper mills; Regeneration of gaseous SO2, e.g. arising from liquors containing sulfur compounds
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
- D21C11/12—Combustion of pulp liquors
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21C—PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCES FROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; APPARATUS THEREFOR
- D21C11/00—Regeneration of pulp liquors or effluent waste waters
- D21C11/12—Combustion of pulp liquors
- D21C11/122—Treatment, e.g. dissolution, of the smelt
Landscapes
- Paper (AREA)
- Treating Waste Gases (AREA)
Abstract
A method for reducing emissions of detrimental nitrogen compounds from the chemical cycle of a pulp mill. The method comprises supplying ammoniacontaining vent gases separated from salt smelt to the furnace of a boiler (1, 10) at a point where the fuel has mainly burnt, whereby the ammonia reacts with the nitrogen oxide present in the furnace to form molecular nitrogen.
Description
CA 02266492 l999-03-l8 METHOD FOR REDUCING EMISSIONS OF DETRIMENTAL NITROGEN
COMPOUNDS
The invention relates to a method for reducing emissions of 5 detrimental nitrogen compounds from the chemical cycle of a pulp mill, said method comprising supplying black liquor produced in the chemical cycle to a recovery boiler for combustion, whereby smelt is formed on the bottom of the recovery boiler as a result of the combustion, said smelt being supplied to a dissolving tank to be dissolved in a liquid containing mainly water.
Various chemical compounds detrimental to the environment and the atmosphere are produced in a sulphate pulp mill. Examples of such compounds are various oxides of sulphur and nitrogen, and ammonia, which is formed in certain steps of the chemical cycle. Attempts have been made to reduce the emissions of nitrogen compounds, mainly nitrogen oxides, from 15 recovery boilers and power boilers by the use of so-called stepped combustion, in which air is supplied to a boiler in several successive steps so that the combustion takes place mainly in under-stoichiometric conditions. In this case, the formation of so-called thermal NOX can be reduced considerably.
Such a solution is disclosed, for example, in Swedish Published Specification 20 No. 468 171.
There have also been attempts to reduce the NOX contents of flue gases by supplying various reagents to the flue gases for preventing the formation of NOX compounds or for converting them to a form in which they can be removed as easily as possible. Such an additive may be ammonia or 25 urea purchased outside the mill, in which case the NO present in the flue gasreacts with the ammonia, forming gaseous nitrogen which can be discharged to the atmosphere. It is also possible to use various solid or liquid ammonium salts as the reagent in this so-called SNCR method known per se. The problems with this technique are that it is expensive to purchase the reagent 30 outside the mill, and that it is difficult to adjust the amount of ammonia supplied to flue gases suitably so that all ammonia is consumed in the reaction and no ammonia residues remain in the flue gases to be discharged to the atmosphere .
It is also known to supply hydrocarbons, such as natural gas or the 35 like, to the flue gases of a boiler. In this case, the reduction of NOX compounds is based on the fact that the hydrocarbon radicals speed up the reactions of W O 9~112378 PCT~7/00563 nitrogen compounds. The drawback of such methods is that they are expensive, since they require heavy investments and the operating costs are high: the additives must be purchased outside the mill, and in addition, equipment is required for storing, batching, adjusting and feeding the 5 additives.
Finnish Patent Application No. 931055 discloses a method in which oxygenous hydrocarbon obtained in the pulp cooking process, such as methanol, is supplied to the flue gases of a recovery boiler. In this method, the methanol and any aqueous steam are supplied to the upper part of a recovery 10 boiler to be mixed with flue gases, whereafter the flue gases are washed withwhite liquor or with an aqueous solution containing ammonia- and/or alkali-based compounds. The method is based on the fact that the nitrogen oxide NO contained in the flue gases is partly oxidated to a nitrogen dioxide NO2, which can be removed by an alkali scrubber. The drawback of this method is 15 that it has an effect only on the reduction of the oxides of already formed nitrogen, and the only reagent that can be used is methanol or a corresponding hydrocarbon derivative. In addition, the method requires a flue gas scrubber suitable for removing NO2, and the treatment of the nitrogen compounds remaining in the washing liquid is still problematic.
In the chemical cycle of a pulp mill, ammonia emissions are caused by nitrogen derived from wood, for example, during the combustion process of black liquor. The salt smelt obtained as a result of the combustion of liquor contains nitrogen compounds which are converted into ammonia during the dissolution of the smelt and in the following process steps. The ammonia 25 produced is further released to the vent gases of the dissolving tank, for example. The odour of the vent gases is problematic in view of the environment, and therefore the vent gases must normally be treated. It is known to wash the vent gases of a dissolving tank with water in order to reduce ammonia emissions to the environment or to supply them with other 30 odour gases of the pulp mill to an odour gas boiler, where they are burnt separately. This causes extra costs, and the flue gases of the odour gas boiler must still be washed in a scrubber, whereby the nitrogen compounds accumulated in the scrubber present a treatment problem.
The object of the present invention is to provide a method for 35 reducing emissions of detrimental nitrogen compounds from the chemical r-W 098/12378 PCT~I97/00563 cycle of a pulp mill by which the drawbacks of the prior art solutions can be avoided.
The method of the invention is characterized by supplying ammonia-containing vent gases separated from the smelt during the 5 dissolution and/or in process steps following the dissolution to the furnace of a boiler of the pulp mill at a point where the fuel supplied to the boiler has mainly burnt, whereby the ammonia contained in the vent gases reacts with the nitrogen oxide present in the furnace of the boiler to form molecular nitrogen.
The essential feature of the invention is that a detrimental nitrogen 10 compound discharged from the chemical cycle of a pulp mill as an emission is used for removing another detrimental nitrogen compound discharged from the chemical cycle of the pulp mill so that the result is normal molecular nitrogen that can be freely discharged to the atmosphere. When implemented in this manner, the invention has the advantage that it allows separate 15 treatment of two detrimental compounds to be at least partly avoided, when no reagents purchased outside the mill or equipment for treating them are required for this purpose.
In the following, the invention will be described in greater detail with reference to the accompanying drawing, which is a schematic illustration of the 20 part of the equipment of a pulp mill required for applying the invention.
The figure is a schematic view of a recovery boiler 1, to which black liquor is supplied from an evaporator through a liquor supply channel 2. As a result of black liquor combustion in the recovery boiler, a smelt bed 3 is formed in the lower part of the recovery boiler. From the smelt bed 3, the smelt flows 25 through a smelt chute 4 to a dissolving tank 5, where it is dissolved in a liquid containing mainly water, i.e. white liquor, NaOH, water or a mixture of these.
The flue gases which are formed in the recovery boiler during the combustion and which contain nitrogen oxides flow to the upper part of the recovery boiler 1 and are discharged through a flue gas duct 6.
During the combustion of black liquor, such nitrogen compounds are formed in the recovery boiler 1 that once said compounds have been supplied to the dissolving tank 5 with the smelt, they are converted into ammonia. The ammonia is released from the solution and discharged with vent gases from the dissolving tank through a vent gas duct 7. The vent gases 35 of the dissolving tank also contain aqueous steam. The steam is preferably removed before the vent gases are supplied to the boiler. For this purpose it is W O98/12378 PCTAF~7/00563 possible to use a condensating scrubber 8, from which the vent gases are supplied through a duct 8a to the recovery boiler at a point where the combustion of black liquor is at least mainly completed. In this case, the ammonia present in the vent gases reacts with the nitrogen oxide contained in 5 the flue gases of the recovery boiler in accordance with the following formula:
6NO + 4NH3 => 5N2 + 6~2O.
The optimum temperature for the reaction is 900~C, but if desired 10 the temperature window of the recovery boiler can be expanded by supplying suitable additives, such as methanol or ethanol, to the furnace. These additives can be supplied to the recovery boiler either with the ammonia-containing vent gases discharged from the dissolving tank 5 or separately from them. In view of the application of the invention, an optimal point at which the15 additives can be supplied to the recovery boiler 1 is below the beak 9 of theboiler, where the temperature is the most suitable for the supply of ammonia-containing vent gases. If the boiler has a so-called upper-tertiary air register, the vent gases can be supplied to the boiler 1 therethrough. Alternatively, separate feed openings can be provided for the supply of vent gases. In some 20 cases, a tertiary air register may also be suitable for the supply of vent gases to achieve a desired effect.
In addition to a recovery boiler, the figure illustrates a power boiler 10 of a pulp mill, to which fuel is supplied through a fuel channel 11. Since nitrogen oxides are also formed in a conventional power boiler, the invention 25 can also be applied by supplying ammonia-containing vent gases of a dissolving tank 5 to the power boiler 10 as shown in the figure, i.e. through channel 8a, according to the principle disclosed in connection with the recovery boiler 1. In this case, the ammonia-containing vent gases are supplied to a temperature of about 900~G at a point where the fuel supplied to 30 the power boiler 10 has mainly burnt, and the nitrogen oxide is reacted with the ammonia in accordance with the formula disclosed above. The flue gases of the power boiler are supplied further through a flue gas duct 12.
A significant advantage of the invention is that it allows emissions of nitrogen oxides of a boiler to be substantially reduced by utilizing another 35 detrimental nitric compound formed in a pulp mill, i.e. ammonia. The nitrogenoxide and ammonia are reacted with each other to form molecular nitrogen, W O 98/12378 PCTrFI97/00563 which is harmless and can thus be freely discharged to the atmosphere. The use of reagents that have to be purchased and investments in equipment can be avoided, since the necessary equipment already exists in a pulp mill.
Furthermore, the invention aliows considerable savings to be achieved in the 5 treatment of flue gases and vent gases, since these gases can be treated with fewer reagents and simpler equipment.
In the specification above and in the drawing, the invention has been described merely by way of example, and it is by no means limited to this example. If desired, ammonia-containing vent gases can be supplied from the 10 dissolving tank 5 past the scrubber 8 directly to the recovery boiler or power boiler through duct 7', indicated with broken lines, and duct 8a. Instead of thedissolving tank, or in addition to it, it is also possible to supply ammonia-containing gases from the following process steps, such as a causticizing department. The temperature range of the supply point may naturally vary to a 15 certain extent, the preferred temperature range being 800~C to 1000~C. The essential thing is that the ammonia separated in a dissolving tank or in the following process steps from the smelt formed in a recovery boiler of a pulp mill is supplied to the recovery boiler or a power boiler in such a manner that,when reacting in the furnace of the boiler with the nitrogen oxide contained in 20 the flue gases, it forms molecular nitrogen and thus reduces nitrogen oxide emissions from the boiler. It will be obvious that, if necessary, the flue gases of both a recovery boiler and a power boiler can be further purified in a suitable manner to remove any remaining impurities.
COMPOUNDS
The invention relates to a method for reducing emissions of 5 detrimental nitrogen compounds from the chemical cycle of a pulp mill, said method comprising supplying black liquor produced in the chemical cycle to a recovery boiler for combustion, whereby smelt is formed on the bottom of the recovery boiler as a result of the combustion, said smelt being supplied to a dissolving tank to be dissolved in a liquid containing mainly water.
Various chemical compounds detrimental to the environment and the atmosphere are produced in a sulphate pulp mill. Examples of such compounds are various oxides of sulphur and nitrogen, and ammonia, which is formed in certain steps of the chemical cycle. Attempts have been made to reduce the emissions of nitrogen compounds, mainly nitrogen oxides, from 15 recovery boilers and power boilers by the use of so-called stepped combustion, in which air is supplied to a boiler in several successive steps so that the combustion takes place mainly in under-stoichiometric conditions. In this case, the formation of so-called thermal NOX can be reduced considerably.
Such a solution is disclosed, for example, in Swedish Published Specification 20 No. 468 171.
There have also been attempts to reduce the NOX contents of flue gases by supplying various reagents to the flue gases for preventing the formation of NOX compounds or for converting them to a form in which they can be removed as easily as possible. Such an additive may be ammonia or 25 urea purchased outside the mill, in which case the NO present in the flue gasreacts with the ammonia, forming gaseous nitrogen which can be discharged to the atmosphere. It is also possible to use various solid or liquid ammonium salts as the reagent in this so-called SNCR method known per se. The problems with this technique are that it is expensive to purchase the reagent 30 outside the mill, and that it is difficult to adjust the amount of ammonia supplied to flue gases suitably so that all ammonia is consumed in the reaction and no ammonia residues remain in the flue gases to be discharged to the atmosphere .
It is also known to supply hydrocarbons, such as natural gas or the 35 like, to the flue gases of a boiler. In this case, the reduction of NOX compounds is based on the fact that the hydrocarbon radicals speed up the reactions of W O 9~112378 PCT~7/00563 nitrogen compounds. The drawback of such methods is that they are expensive, since they require heavy investments and the operating costs are high: the additives must be purchased outside the mill, and in addition, equipment is required for storing, batching, adjusting and feeding the 5 additives.
Finnish Patent Application No. 931055 discloses a method in which oxygenous hydrocarbon obtained in the pulp cooking process, such as methanol, is supplied to the flue gases of a recovery boiler. In this method, the methanol and any aqueous steam are supplied to the upper part of a recovery 10 boiler to be mixed with flue gases, whereafter the flue gases are washed withwhite liquor or with an aqueous solution containing ammonia- and/or alkali-based compounds. The method is based on the fact that the nitrogen oxide NO contained in the flue gases is partly oxidated to a nitrogen dioxide NO2, which can be removed by an alkali scrubber. The drawback of this method is 15 that it has an effect only on the reduction of the oxides of already formed nitrogen, and the only reagent that can be used is methanol or a corresponding hydrocarbon derivative. In addition, the method requires a flue gas scrubber suitable for removing NO2, and the treatment of the nitrogen compounds remaining in the washing liquid is still problematic.
In the chemical cycle of a pulp mill, ammonia emissions are caused by nitrogen derived from wood, for example, during the combustion process of black liquor. The salt smelt obtained as a result of the combustion of liquor contains nitrogen compounds which are converted into ammonia during the dissolution of the smelt and in the following process steps. The ammonia 25 produced is further released to the vent gases of the dissolving tank, for example. The odour of the vent gases is problematic in view of the environment, and therefore the vent gases must normally be treated. It is known to wash the vent gases of a dissolving tank with water in order to reduce ammonia emissions to the environment or to supply them with other 30 odour gases of the pulp mill to an odour gas boiler, where they are burnt separately. This causes extra costs, and the flue gases of the odour gas boiler must still be washed in a scrubber, whereby the nitrogen compounds accumulated in the scrubber present a treatment problem.
The object of the present invention is to provide a method for 35 reducing emissions of detrimental nitrogen compounds from the chemical r-W 098/12378 PCT~I97/00563 cycle of a pulp mill by which the drawbacks of the prior art solutions can be avoided.
The method of the invention is characterized by supplying ammonia-containing vent gases separated from the smelt during the 5 dissolution and/or in process steps following the dissolution to the furnace of a boiler of the pulp mill at a point where the fuel supplied to the boiler has mainly burnt, whereby the ammonia contained in the vent gases reacts with the nitrogen oxide present in the furnace of the boiler to form molecular nitrogen.
The essential feature of the invention is that a detrimental nitrogen 10 compound discharged from the chemical cycle of a pulp mill as an emission is used for removing another detrimental nitrogen compound discharged from the chemical cycle of the pulp mill so that the result is normal molecular nitrogen that can be freely discharged to the atmosphere. When implemented in this manner, the invention has the advantage that it allows separate 15 treatment of two detrimental compounds to be at least partly avoided, when no reagents purchased outside the mill or equipment for treating them are required for this purpose.
In the following, the invention will be described in greater detail with reference to the accompanying drawing, which is a schematic illustration of the 20 part of the equipment of a pulp mill required for applying the invention.
The figure is a schematic view of a recovery boiler 1, to which black liquor is supplied from an evaporator through a liquor supply channel 2. As a result of black liquor combustion in the recovery boiler, a smelt bed 3 is formed in the lower part of the recovery boiler. From the smelt bed 3, the smelt flows 25 through a smelt chute 4 to a dissolving tank 5, where it is dissolved in a liquid containing mainly water, i.e. white liquor, NaOH, water or a mixture of these.
The flue gases which are formed in the recovery boiler during the combustion and which contain nitrogen oxides flow to the upper part of the recovery boiler 1 and are discharged through a flue gas duct 6.
During the combustion of black liquor, such nitrogen compounds are formed in the recovery boiler 1 that once said compounds have been supplied to the dissolving tank 5 with the smelt, they are converted into ammonia. The ammonia is released from the solution and discharged with vent gases from the dissolving tank through a vent gas duct 7. The vent gases 35 of the dissolving tank also contain aqueous steam. The steam is preferably removed before the vent gases are supplied to the boiler. For this purpose it is W O98/12378 PCTAF~7/00563 possible to use a condensating scrubber 8, from which the vent gases are supplied through a duct 8a to the recovery boiler at a point where the combustion of black liquor is at least mainly completed. In this case, the ammonia present in the vent gases reacts with the nitrogen oxide contained in 5 the flue gases of the recovery boiler in accordance with the following formula:
6NO + 4NH3 => 5N2 + 6~2O.
The optimum temperature for the reaction is 900~C, but if desired 10 the temperature window of the recovery boiler can be expanded by supplying suitable additives, such as methanol or ethanol, to the furnace. These additives can be supplied to the recovery boiler either with the ammonia-containing vent gases discharged from the dissolving tank 5 or separately from them. In view of the application of the invention, an optimal point at which the15 additives can be supplied to the recovery boiler 1 is below the beak 9 of theboiler, where the temperature is the most suitable for the supply of ammonia-containing vent gases. If the boiler has a so-called upper-tertiary air register, the vent gases can be supplied to the boiler 1 therethrough. Alternatively, separate feed openings can be provided for the supply of vent gases. In some 20 cases, a tertiary air register may also be suitable for the supply of vent gases to achieve a desired effect.
In addition to a recovery boiler, the figure illustrates a power boiler 10 of a pulp mill, to which fuel is supplied through a fuel channel 11. Since nitrogen oxides are also formed in a conventional power boiler, the invention 25 can also be applied by supplying ammonia-containing vent gases of a dissolving tank 5 to the power boiler 10 as shown in the figure, i.e. through channel 8a, according to the principle disclosed in connection with the recovery boiler 1. In this case, the ammonia-containing vent gases are supplied to a temperature of about 900~G at a point where the fuel supplied to 30 the power boiler 10 has mainly burnt, and the nitrogen oxide is reacted with the ammonia in accordance with the formula disclosed above. The flue gases of the power boiler are supplied further through a flue gas duct 12.
A significant advantage of the invention is that it allows emissions of nitrogen oxides of a boiler to be substantially reduced by utilizing another 35 detrimental nitric compound formed in a pulp mill, i.e. ammonia. The nitrogenoxide and ammonia are reacted with each other to form molecular nitrogen, W O 98/12378 PCTrFI97/00563 which is harmless and can thus be freely discharged to the atmosphere. The use of reagents that have to be purchased and investments in equipment can be avoided, since the necessary equipment already exists in a pulp mill.
Furthermore, the invention aliows considerable savings to be achieved in the 5 treatment of flue gases and vent gases, since these gases can be treated with fewer reagents and simpler equipment.
In the specification above and in the drawing, the invention has been described merely by way of example, and it is by no means limited to this example. If desired, ammonia-containing vent gases can be supplied from the 10 dissolving tank 5 past the scrubber 8 directly to the recovery boiler or power boiler through duct 7', indicated with broken lines, and duct 8a. Instead of thedissolving tank, or in addition to it, it is also possible to supply ammonia-containing gases from the following process steps, such as a causticizing department. The temperature range of the supply point may naturally vary to a 15 certain extent, the preferred temperature range being 800~C to 1000~C. The essential thing is that the ammonia separated in a dissolving tank or in the following process steps from the smelt formed in a recovery boiler of a pulp mill is supplied to the recovery boiler or a power boiler in such a manner that,when reacting in the furnace of the boiler with the nitrogen oxide contained in 20 the flue gases, it forms molecular nitrogen and thus reduces nitrogen oxide emissions from the boiler. It will be obvious that, if necessary, the flue gases of both a recovery boiler and a power boiler can be further purified in a suitable manner to remove any remaining impurities.
Claims (7)
1. A method for reducing emissions of detrimental nitrogen compounds from the chemical cycle of a pulp mill, said method comprising supplying black liquor produced in the chemical cycle to a recovery boiler for combustion, whereby smelt is formed on the bottom of the recovery boiler as a result of the combustion, said smelt being supplied to a dissolving tank to be dissolved in a liquid containing mainly water, characterized by supplying ammonia-containing vent gases separated from the smelt during the dissolution and/or in process steps following the dissolution to the furnace of a boiler (1, 10) of the pulp mill at a point where the fuel supplied to the boiler (1, 10) has mainly burnt, whereby the ammonia contained in the vent gases reacts with the nitrogen oxide present in the furnace of the boiler (1, 10) to form molecular nitrogen.
2. A method according to claim 1, characterized in that aqueous steam is removed from the vent gases prior to supplying them to the boiler (1, 10).
3. A method according to claim 1 or 2, characterized in that the vent gases are supplied to the furnace of the boiler (1, 10) at a point where the temperature is 800°C to 1000°C.
4. A method according to any one of the preceding claims, characterized in that the vent gases are supplied to the furnace of a recovery boiler (1) to remove nitrogen oxides formed in the recovery boiler (1) during combustion.
5. A method according to any one of the preceding claims, characterized in that the vent gases are supplied to the furnace of a power boiler (10) of the pulp mill to remove nitrogen oxides formed therein during combustion.
6. A method according to claim 4, characterized in that the vent gases are supplied to the furnace below the beak.
7. A method according to any one of the preceding claims, characterized in that vent gases produced in the liquor causticizing step are supplied to the boiler.
Applications Claiming Priority (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI963758A FI963758A0 (en) | 1996-09-20 | 1996-09-20 | Foerfarande Foer att minska utslaepp av skadliga kvaevefoereningar fraon en Cellulosa Fabriks kemikaliecirkulation |
| FI963758 | 1996-09-20 | ||
| FI973236A FI110793B (en) | 1996-09-20 | 1997-08-05 | Procedure for reducing the emissions of harmful nitrogen compounds in the chemical circulation of a cellulose plant |
| FI973236 | 1997-08-05 | ||
| PCT/FI1997/000563 WO1998012378A1 (en) | 1996-09-20 | 1997-09-19 | Method for reducing emissions of detrimental nitrogen compounds |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2266492A1 true CA2266492A1 (en) | 1998-03-26 |
Family
ID=26160217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002266492A Abandoned CA2266492A1 (en) | 1996-09-20 | 1997-09-19 | Method for reducing emissions of detrimental nitrogen compounds |
Country Status (6)
| Country | Link |
|---|---|
| AU (1) | AU4386197A (en) |
| BR (1) | BR9714340A (en) |
| CA (1) | CA2266492A1 (en) |
| FI (1) | FI110793B (en) |
| SE (1) | SE517575C2 (en) |
| WO (1) | WO1998012378A1 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FI105704B (en) * | 1998-03-19 | 2000-09-29 | Kvaerner Pulping Oy | Procedure for reducing the emission of harmful nitrogen compounds by a cellulose factory |
| FI129360B (en) | 2009-04-15 | 2021-12-31 | Andritz Oy | Method of reducing flue gas emissions and boiler |
| US10206918B2 (en) | 2012-12-13 | 2019-02-19 | Immunomedics, Inc. | Efficacy of anti-HLA-DR antiboddy drug conjugate IMMU-140 (hL243-CL2A-SN-38) in HLA-DR positive cancers |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE9504450L (en) * | 1995-12-13 | 1996-10-28 | Kvaerner Pulping Tech | Procedure for reducing the content of NOx in a soda boiler and a soda boiler therefor |
-
1997
- 1997-08-05 FI FI973236A patent/FI110793B/en not_active IP Right Cessation
- 1997-09-19 WO PCT/FI1997/000563 patent/WO1998012378A1/en active Application Filing
- 1997-09-19 BR BR9714340-5A patent/BR9714340A/en not_active IP Right Cessation
- 1997-09-19 AU AU43861/97A patent/AU4386197A/en not_active Abandoned
- 1997-09-19 CA CA002266492A patent/CA2266492A1/en not_active Abandoned
-
1999
- 1999-03-16 SE SE9900940A patent/SE517575C2/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| FI110793B (en) | 2003-03-31 |
| BR9714340A (en) | 2000-04-11 |
| WO1998012378A1 (en) | 1998-03-26 |
| FI973236A0 (en) | 1997-08-05 |
| SE9900940D0 (en) | 1999-03-16 |
| SE517575C2 (en) | 2002-06-18 |
| AU4386197A (en) | 1998-04-14 |
| SE9900940L (en) | 1999-03-16 |
| FI973236A (en) | 1998-03-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued |