WO1994020676A1 - Procede d'epuration des gaz de combustion dans une chaudiere de recuperation - Google Patents

Procede d'epuration des gaz de combustion dans une chaudiere de recuperation Download PDF

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Publication number
WO1994020676A1
WO1994020676A1 PCT/FI1994/000084 FI9400084W WO9420676A1 WO 1994020676 A1 WO1994020676 A1 WO 1994020676A1 FI 9400084 W FI9400084 W FI 9400084W WO 9420676 A1 WO9420676 A1 WO 9420676A1
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WO
WIPO (PCT)
Prior art keywords
methanol
compounds
recovery furnace
scrubbing liquid
oxygen
Prior art date
Application number
PCT/FI1994/000084
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English (en)
Inventor
Pauli Dernjatin
Harri Kannela
Pia Salokoski
Hanne Siikavirta
Original Assignee
Imatran Voima Oy
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Imatran Voima Oy filed Critical Imatran Voima Oy
Priority to AU62088/94A priority Critical patent/AU6208894A/en
Publication of WO1994020676A1 publication Critical patent/WO1994020676A1/fr

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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
    • B01D53/60—Simultaneously removing sulfur oxides and nitrogen oxides
    • 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

Definitions

  • the present invention relates to a method according to the preamble of claim 1 for cleaning the flue gases of a recovery furnace.
  • flue gases are contacted with a scrubbing liquid in a flue gas scrubber to the end of absorbing the sulfur and nitrogen oxides contained in the flue gases, and when desirable, subjecting the spent scrubbing liquid containing absorbed sulfur and nitrogen compounds to further processing to the end of recovering said compounds.
  • the invention also concerns a method as defined in the preamble of claim 13 for reducing the quantity of oxygen-containing compounds in the contaminated con ⁇ densates of a cellulose manufacturing process.
  • simultaneous methods have been developed in which nitrogen and sulfur oxides are removed concurrently.
  • Simultaneous methods are categorized as dry and wet methods. Dry methods are based on the use of a catalyst or adsorption. Wet methods are based on simultaneous removal of nitrogen and sulfur oxides by means of scrubber techniques.
  • the scrubber technique is conventionally used for, e.g., removal of sulfur oxides from the flue gases of a recovery furnace in the pulp industry.
  • Simultaneous removal of nitrogen oxides in a scrubber designed for sulfur removal presumes the oxidation of nitric oxide to nitrogen dioxide, or alternatively, the dosing of nitric oxide absorption promoting additives into the scrubbing liquid.
  • the invention is based on the concept of injecting an oxygen-containing hydro ⁇ carbon derivative to the recovery furnace to the end of oxidizing the nitric oxide.
  • the oxygen-containing hydrocarbon derivative used herein can be methanol, ethanol, acetone or similar compound obtained from the pulping process.
  • the gases are scrubbed with a scrubbing liquid which reacts with the sulfur dioxide contained in the flue gases so as to form sulfite compounds and possibly also bisulfite compounds which then react with the nitrogen dioxide.
  • the method according to the invention for cleaning the flue gases of a recovery furnace is principally characterized by what is stated in the characterizing part of claim 1.
  • the method for reducing the quantity of oxygen-containing hydro ⁇ carbon derivatives contained in condensates and converting said compounds to a harmless form is characterized by what is stated in the characterizing part of claim 13.
  • the term "recovery furnace” refers to such a recovery furnace or boiler in which the concentrated waste liquor resulting from pulp cooking is combusted.
  • One purpose of such a combustion process is energy recovery from waste liquor by producing, e.g., steam.
  • the waste liquor combusted in the recovery furnace typically contains sulfide compounds which in the combustion process are converted to sulfur dioxide. Additionally, the combustion process generates nitrogen oxides (NO ⁇ ), part of which occur as nitric oxide.
  • the oxidation of NO with the help of methanol or similar oxygen-containing hydrocarbon derivatives is implemented through the injection of liquid or vaporized methanol along with a suitable carrier to the furnace at a point where the flue gas temperature is approx. 500 - 900 °C.
  • the decomposition of methanol produces HO radicals which perform the oxidation of NO to NO 2 in accordance with Eq. I:
  • the above reaction can take place in both directions and it has an optimum retention time which is dependent on the reaction temperature.
  • the methanol (and other oxygen-containing com ⁇ pounds) used in the oxidation of nitric oxide is obtained from the pulping process.
  • a contaminated condensate containing methanol, foul-smelling sulfur compounds and other organic compounds can be purified by steam distillation, air stripping or biological treatment. Distillation by steam stripping is a conventional method particularly favored in the Nordic countries. According to the present method, the methanol separated by steam stripping is advantageously condensed and purified prior to its use for oxidation of nitric oxide. This is because the methanol gas obtained from the steam stripping step also contains sulfur compounds. However, as their boiling point is lower than that of methanol, methanol is condensed first in the condensation step thus being recovered in pure form, whereby no smell problems are incurred by the sulfur compounds. Further ⁇ more, handling of liquid methanol is easier. Conventionally, a separate column is required for the condensation step.
  • the amount of methanol formed in the pulp cooking process is approx. 6 - 13 kg per ton of pulp, and it causes the major portion of the BOD content imposed by condensates, namely, approx. 60 - 80 % of the total BOD.
  • ethanol is formed in amounts of approx. 1 kg/tn pulp and acetone approx. 0.15 kg/tn pulp.
  • Methanol can be injected to the recovery furnace in liquid or gas phase.
  • the methanol obtained from the steam stripping and subsequently condensed and puri ⁇ fied can be fed to the furnace as an aqueous solution of suitable concentration.
  • the condensed methanol can be vaporized and fed to the recovery furnace along with a suitable carrier medium.
  • Effective mixing of the methanol in the flue gases is implemented by means of jet nozzles.
  • concentration of methanol in its aqueous solution or gas phase is dependent on the dimensions of the recovery furnace, required number of jet nozzles and their location.
  • safety precaution must be taken against potential explosion hazards.
  • the injection rate of the methanol-water or methanol-carrier mixture is dimensioned so that the methanol jets cover the entire cross section of the flue gas duct at the injection point and provide as effective mixing as possible.
  • methanol concentration in the injection feedstock should be either below 5 %, or advantageously, greater than 25 %. Most advanta ⁇ geously the methanol concentration is approx. 30 - 60 %, typically approx. 40 - 50 %.
  • the methanol injection can be complemented with or replaced by injection of other hydrocarbon derivatives such as ethanol or acetone, both of which are obtainable from the contaminated condensate streams.
  • the injection of the oxygen-containing hydrocarbon derivative compounds obtained from the cooking process to the recovery furnace can be complemented with a feedstock of corresponding pure chemicals when desired.
  • feedstock is disclosed in, i.a., US patent publication 4,350,669, GB patent publication 1,547,531 and JP patent application 54-55602 (ABIPC Vol. 51, No. 2 (1980), Abstract No. 2356).
  • these publications do not teach the use of cooking-process-based methanol as the reactive feedstock.
  • the use of the cooking-process-based methanol achieves significant savings in process operating costs and thus also contributes to the alleviation of the contaminated condensates handling problem.
  • methanol can be recovered from the condensates by means of a purpose-designed separating unit such as a steam distillation (steam stripping) or distillation plant.
  • Oxygen-containing hydrocarbon derivative compounds are injected to the recovery furnace at a point where the flue gas temperature is approx. 500 - 900 °C. This zone is typically at the level of the furnace tube wall and the superheater tubes.
  • the retention time is typically in the order of 0.05 - 5 s, advantageously approx. 0.1 - 1.5 s. If the hydrocarbon derivative compounds are fed to the temperature zone of, e.g., approx. 600 - 650 °C, the retention time can be designed for, e.g., approx. 0.5 - 1 s.
  • methanol is advantageously injected in excess relative to the content of nitrogen oxides in the flue gases. Accordingly, the mole ratio in which methanol is mixed with the nitrogen oxides of flue gases is maintained at a value greater than 1, advantageously in the range of approx. 1.2 - 5. High values of the mole ratio are advantageous to the oxidation of nitrogen oxides, whilst the formation of carbon monoxide is simultaneously increased.
  • the flue gas scrubbers following the recovery furnace are wetted with scrubbing liquids containing compounds which react with sulfur dioxide forming sulfite compounds and possibly also bisulfite compounds. These compounds are in the context of the present patent application generally referred to as "sulfite compounds".
  • Scrubbing liquors which typically are in the form of aqueous solutions may contain ammonium compounds such as ammonium sulfide, ammonium hydroxide or ammonium carbonate, or alternatively, they may contain alkali metal compounds such as sodium sulfide, sodium hydroxide and/or sodium carbonate.
  • the scrubbing liquids may also be comprised of the mixtures of the above-listed compounds.
  • pure chemicals may be complemented with, e.g., white liquor.
  • pulp cooking processes chiefly employ sodium-based cooking liquors, and also to some extent, ammonium-based cooking liquors, cooking techniques based on such cationic liquors are particularly advantageously compatible with the present invention.
  • sodium sulfite Na 2 SO 3
  • Eq. Ill Eq. Ill given below:
  • sodium bisulfite NaHSO 3
  • ammonium sulfite and bisulfite are formed in ammonium-based scrubbing liquors. Effective absorption of NO 2 in aqueous solutions of the above mentioned compounds has been verified.
  • compositions initially containing sulfite compounds can be partially replaced by compositions initially containing sulfite compounds (e.g., using solutions of ammonium or alkali metal sulfites).
  • the spent scrubbing liquor obtained from the scrubber contains, among other things, sulfite, bisulfite, nitrite and nitrate ions.
  • the spend liquid can be taken to further processing.
  • these compounds are not separated, but rather, the further processing of the spent scrubbing liquor comprises returning the liquor as such to the pulp cooking process.
  • the spent scrubbing liquor is taken to the evaporation plant, or alternatively, it can be taken to the dissolving tank of smelt received from the recovery furnace.
  • the NO 2 ⁇ and NO 3 ⁇ ions contained in the scrubbing liquor are directly routed to the pulp cooking process along with the cooking chemicals.
  • the spend scrubbing liquor is taken to evaporation plant, the nitrogen compounds contained therein remain in the liquor solids which are then combusted in the recovery furnace.
  • the exact path of the nitrogen compounds in the combustion conditions of the recovery furnace is not known exactly, it is plausible that at least a portion of the compounds become entrapped in the smelt and circulated through that path back to the pulp cooking process.
  • the nitrogen compounds also partially end up in the gas phase, where they under the reducing conditions are reduced to nitrogen.
  • the invention offers significant benefits. Namely, methanol formed in the pulp cooking process of sulfate pulp industry can be used for oxidation of NO. Conven ⁇ tionally, methanol and sulfur compounds have been considered to form the most problematic source of foul-smelling emissions from a pulp mill, and consequently, methanol-rich steam (with a methanol content of 40 - 50 %) has directly been taken to combustion in the prior art.
  • the present invention provides an entirely novel method for reducing the quantity of such oxygen-containing com ⁇ pounds incorporated in contaminated condensates and converting them to non- hazardous compounds, whereby said method simultaneously is capable of reducing nitrogen oxide emissions from the recovery furnace.
  • the present invention comprises feeding the mixture of steam from steam stripping and the oxygen-containing compounds to the recovery fur ⁇ nace where the oxygen-containing compounds are reacted in gas phase with nitric oxide to form nitrogen dioxide.
  • the NO ⁇ -containing flues gases of the recovery furnace are scrubbed in a flue gas scrubber with a scrubbing liquid containing at least a certain amount of sulfite ions, the scrubbing liquid is circulated in the scrubber and the spent scrubbing liquid is taken to the evaporation plant or the dissolving tank of the smelt obtained from the recovery furnace.
  • Figure 1 is a process flow diagram of the method according to the invention
  • Figure 2 is a diagrammatic view of the bench-scale test setup used in Example 1 ;
  • Figure 3 is a graph showing the effect of a fixed bed in the reactor on the oxidation of NO (that is, NO conversion vs. temperature);
  • Figure 4 is a diagrammatic view of the bench-scale test setup used in Example 2;
  • Figure 5 is a graph showing the proportion of NO x absorbed in the scrubbing liquid as a function of the NO 2 :NO ratio;
  • Figure 6 is a graph showing the analysis results of the scrubbing liquid in a test where all NO ⁇ was NO 2 .
  • the apparatus comprises a recovery furnace 1, an electrostatic precipitator 2 and a scrubber 3.
  • the different zones of the recovery furnace are marked with reference numerals so that the furnace of the soda recovery boiler is indicated by reference numeral 4, the boiler tube wall is indicated by reference number 5, the superheater by reference numeral 6, the boiler tubes by reference numeral 7 and the water preheater by reference numeral 8.
  • the internal temperature of the recovery furnace varies according to the above-mentioned zones so that the temperature at furnace 4 is greater than 1000 °C (usually approx. 1200 - 1400 °C), at the furnace tube wall 5 and the superheater 6 approx. 500 - 900 °C and at the boiler tubes 7 and the water preheater 8 approx.
  • the recovery furnace 1 is further provided with an inlet pipe 9 of the methanol mixture obtained from the pulp cooking process, methanol injection nozzles 10 and flue gas duct 11 to which an electrostatic precipitator 2 is connected.
  • the electrostatic precipitator is followed by the flue gas scrubber 3 having a first zone 12, which is the actual scrubbing zone, and a second zone 13, where heat recovery takes place.
  • the scrubber is provides with a stack 14.
  • the method according to the invention is applied to, e.g., a conventional sulfate pulping process. Accordingly, a recovery furnace 1 is fed with black liquor comprising spent cooking liquor which is separated and recovered at maximum concentration.
  • the recovered black liquor is further concentrated by evaporation prior to taking it to combustion in the recovery furnace 1 to the end of recovering the cooking chemicals and the energy contained in the black liquor.
  • the smelt of chemical salts obtained from the recovery furnace 1 is regenerated to form fresh white liquor.
  • the steam stripping of contaminated condensate streams provides a condensate rich in methanol and possibly other oxygen-containing hydrocarbon derivatives that is injected to the upper part of the recovery furnace 1 via a methanol inlet pipe 9.
  • the methanol-steam mixture is injected to the recovery furnace at a point (zones 5 - 6) where the flue gas temperature is approx. 500 - 900 °C.
  • the injection is implemented with the help of high-pressure jet nozzles
  • the jet nozzles can also be used for introducing an additional amount of a carrier medium such as steam to the recovery furnace.
  • the methanol-steam mixture is injected to the flue gas flow in either liquid or vapor phase, whereby the nitric oxide contained in the flue gases reacts with the methanol forming nitrogen dioxide.
  • the flue gases are cooled in the heat recovery zones 5 - 8 of the recovery furnace prior to taking them via the electrostatic precipitator 2 to the scrubber 3.
  • the electrostatic precipitator performs the separation of fly ash and other particulates from the flue gases.
  • the flue gases are scrubbed in a contacting zone 12 of the scrubber by an alkaline scrubbing liquor which is introduced via atomizing spray nozzles 12' to the scrubber 3.
  • the alkaline scrubbing liquid employed can be an aqueous solution of, e.g., sodium hydroxide or white liquor.
  • the nitrogen dioxide and sulfur dioxide are bound with the circulating scrubbing liquor forming nitrite, nitrate, sulfite and bisulfite compounds in the liquor.
  • the spent scrubbing liquor obtained from the scrubber is taken either to the dissolving tank of the recovery furnace plant, or alternatively, to the evaporation plant.
  • the unreacted flue gases are discharged from the scrubber via a stack 14.
  • the test setup includes a reactor 15 housing a fixed bed 16.
  • the reactor is placed in a furnace 17.
  • the reactor is fed from gas containers 19 - 21 via a flow rate regulator 18 with a gas mixture containing NO, air (O 2 ) and N .
  • the zone above the fixed bed 16 is fed via an inner pipe 22 with a mixture of CH 3 OH and N 2 .
  • Said mixture is prepared by taking a nitrogen flow from a gas container 23 via a rotameter 24 to a methanol container 25, wherein methanol is evaporated into the nitrogen carrier flow.
  • the internal temperature of the furnace 17 is controlled by means of temperature controller unit (not shown), which for the test of Example 1 was programmed to first elevate the furnace temperature to a desired initial temperature, after which the furnace temperature was ramped up to the end temperature, and correspondingly, lowered back down to the initial temperature at a rate of 4 °C/min.
  • the reacted gas mixture passes via an inner pipe 26 to analyzers 27 - 30.
  • the gas mixture was analyzed for NO, NO 2 and NO ⁇ concen ⁇ trations using a continuous-function chemiluminescence-based NO ⁇ analyzer 27 designated as Monitor Labs type 8840.
  • the CO concentration was measured using an IR-abso ⁇ tion based analyzer 28 designated as Siemens Ultramat 22 and the O 2 concentration was measured using a paramagnetic O 2 analyzer 29 designated as
  • M&C PMA 25 Measurement data was collected by means of a recorder 30.
  • the test setup includes a gas scrubbing bottle 31, which is equipped with a thermostat and a magnetic stirrer (not shown).
  • the apparatus is provided with a sample inlet nozzle 32, which is connected to a tubing pump 33.
  • Reference numeral 34 designates a receiving vessel for the liquid sample pumped from the scrubbing liquid.
  • a gas feed pipe 35 is further adapted to the gas scrubbing bottle 31 with the pipe end lowered so deep that it remains below the surface of the liquid fed into the bottle. Gases can then be passed to the feed pipe 35 via a three-way valve 36, or alternatively, the gas scrubbing bottle can be bypassed.
  • Reference numerals 37 - 41 designate flow-regulating valves. Gas samples can be passed either directly from the gas sources or the gas scrubbing bottle 31 via the three-way valve to the NO ⁇ analyzer 42 and the SO 2 analyzer 43, respectively.
  • the analyzers 42, 43 are connected to a data retrieval unit 44. Diluting air is passed to the SO 2 analyzer to the end of diluting the concentration of the sample to be measured in the sample measuring chamber.
  • a gas mixture was passed at a rate of 3 1/min containing 150 ppm NO, 4.9 vol-% O 2 and 300 ppm CH 3 OH.
  • the gas mixture was analyzed for NO, NO 2 , O 2 and CO.
  • Reaction temperature varied during the test in the range of 500 - 900 °C.
  • the reaction time was 0.3 s.
  • the test setup was equipped with a fixed bed in the reactor vessel. The goal was to assess the effect of a high content of or the properties of the fly ash contained in flue gases of a recovery furnace on the conversion of NO to NO 2 .
  • the maximum conversion under the reaction time used occurs at a temperature of 550 - 650 °C.
  • the fixed bed lowers the conversion by approx. 20 - 30 %.
  • a fixed bed containing approx. 10 wt.-% of Na.--.SO 4 that is, the main component in the fly ash discharge of a recovery furnace lowers NO conversion to a level of approx. 80 %.
  • the solids in this test setup fixed bed is greater by more than 1000-fold (in proportion to gas flow rates) relative to the fly ash content of flue gas discharge from a conventional recovery furnace.
  • a 1 1 aliquot of the scrubbing liquid to be investigated was prepared in a gas scrubbing bottle shown in Fig. 4.
  • the scrubbing liquid was analyzed for pH and the ion concentrations of NO ⁇ and NO 3 ⁇ by ion chromatography.
  • the scrubbing liquid was prepared by dissolving 6.30 g Na 2 SO 3 and 4.75 g Na-,S 2 O 5 to 1 1 distilled water, whereby the pH of the liquid was approx. 6.5.
  • a gas mixture having an NO ⁇ concentration of 250 ppm, an SO 2 concentration of approx. 700 ppm and an O 2 concentration of approx. 5 vol-%.
  • the ratio of NO 2 to NO was varied so that the proportion of NO 2 of total NO x was 50, 70 and 100 %.
  • the proportion of NO ⁇ absorbed in the tested scrubbing liquid is plotted as a function of the NO 2 :NO mole ratio.
  • This example describes a plant-scale implementation of the process illustrated in Fig. 1.
  • the flue gas discharge rate from the recovery furnace is 230 m 3 (NTP)/s (moist).
  • the composition of the flue gas is 5.3 % O 2 , 14.2 % CO 2 , 22 vol-% H 2 O, 500 ppm SO 2 , 100 ppm NO (moist) and 10 ppm CO.
  • Methanol is injected in the recovery furnace at a mole ratio of 3. Then, the methanol consumption is approx. 100 g/s. Methanol is injected in the flue gas flow in the form of an aqueous solution to a temperature zone of 680 °C.
  • composition of the flue gas prior to the scrubber is 5.3 % O 2 , 14.2 % CO 2 , 22 vol-% H 2 O, 500 ppm SO 2 , 40 ppm NO (moist), 60 ppm NO 2 and 150 ppm CO.
  • the flue gases are contacted with an Na-based scrubbing liquor containing SO 3 ions.
  • the composition of the flue gas after the scrubber is 5.3 % O 2 , 14.2 % CO 2 , 50 ppm SO 2 , 40 ppm NO (moist), 1 ppm NO 2 and 150 ppm CO.
  • This example achieves approx. 60 % removal efficiency of NO ⁇ .
  • the spent scrubbing liquor is taken to the evaporation plant and combusted along with the black liquor in the recovery furnace. This arrangement does not increase the NO ⁇ of the flue gas effluent, because the nitrogen compounds of the scrubbing liquor are reduced to N 2 .

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  • 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)

Abstract

Procédé d'épuration des gaz de combustion dans un four de récupération. Selon le procédé, on met les gaz de combustion en contact avec un liquide épurateur dans un appareil (3) d'épuration de gaz de combustion, afin qu'il absorbe les composés de soufre et d'azote compris dans lesdits gaz, et, le cas échéant, on soumet à un nouveau traitement le liquide épurateur renfermant les composés de soufre et d'azote absorbés, afin de récupérer lesdits composés. En outre, on introduit dans le four de récupération (1) un dérivé hydrocarburé renfermant de l'oxygène, par exemple du méthanol produit par un processus de cuisson de pâte cellulosique, en vue d'assurer la transformation par oxydation au moins partielle en dioxyde d'azote de l'oxyde nitrique compris dans les gaz de combustion, puis on fait fonctionner l'appareil (3) d'épuration de gaz de combustion en utilisant un liquide épurateur approprié dans lequel se forment, grâce à l'absorption d'oxyde de soufre, des composés sulfitiques susceptibles de réagir avec le dioxyde d'azote.
PCT/FI1994/000084 1993-03-10 1994-03-09 Procede d'epuration des gaz de combustion dans une chaudiere de recuperation WO1994020676A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU62088/94A AU6208894A (en) 1993-03-10 1994-03-09 Process for purifying the combustion gases of a recovery boiler

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI931055A FI98842C (fi) 1993-03-10 1993-03-10 Menetelmä soodakattilan savukaasujen puhdistamiseksi
FI931055 1993-03-10

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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999047746A1 (fr) * 1998-03-19 1999-09-23 Kvaerner Pulping Oy Procede de reduction de composes nox dans les gaz de combustion de chaudieres de recuperation
WO2000002646A1 (fr) * 1998-07-10 2000-01-20 Biostar Development Cv Procede de nettoyage d'un gaz de combustion
US6030494A (en) * 1997-09-05 2000-02-29 Ahlstrom Machinery Oy Method of treating melodorous gases of a pulp mill
CN103159187A (zh) * 2013-03-27 2013-06-19 山东三维石化工程股份有限公司青岛分公司 硫磺回收及尾气处理装置停工清洁生产工艺
CN115667623A (zh) * 2020-05-27 2023-01-31 维美德公司 用于管理和控制纸浆厂中循环液流系统的氮排放的方法和装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1547531A (en) * 1976-04-16 1979-06-20 Mitsubishi Heavy Ind Ltd Method of purifying combustion exhaust gases
US4350669A (en) * 1976-01-30 1982-09-21 Mitsubishi Jukogyo Kabushiki Kaisha Process for controlling nitrogen oxides in exhaust gases

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4350669A (en) * 1976-01-30 1982-09-21 Mitsubishi Jukogyo Kabushiki Kaisha Process for controlling nitrogen oxides in exhaust gases
GB1547531A (en) * 1976-04-16 1979-06-20 Mitsubishi Heavy Ind Ltd Method of purifying combustion exhaust gases

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ORBIT SEARCH SERVICE, File WPAT, Accession Number 79-44887B/24 ((MITO) MITSUBISHI HEAVY IND KK); & JP,A,54 055 602 (02-05-79). *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6030494A (en) * 1997-09-05 2000-02-29 Ahlstrom Machinery Oy Method of treating melodorous gases of a pulp mill
WO1999047746A1 (fr) * 1998-03-19 1999-09-23 Kvaerner Pulping Oy Procede de reduction de composes nox dans les gaz de combustion de chaudieres de recuperation
US6517793B1 (en) 1998-03-19 2003-02-11 Kvaerner Pulping Oy Method of reducing Nox compounds in flue gases of recovery boiler
WO2000002646A1 (fr) * 1998-07-10 2000-01-20 Biostar Development Cv Procede de nettoyage d'un gaz de combustion
CN103159187A (zh) * 2013-03-27 2013-06-19 山东三维石化工程股份有限公司青岛分公司 硫磺回收及尾气处理装置停工清洁生产工艺
CN115667623A (zh) * 2020-05-27 2023-01-31 维美德公司 用于管理和控制纸浆厂中循环液流系统的氮排放的方法和装置

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FI98842B (fi) 1997-05-15
FI931055A (fi) 1994-09-11
FI931055A0 (fi) 1993-03-10
AU6208894A (en) 1994-09-26
FI98842C (fi) 1997-08-25

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