WO1987002023A1 - Reduction de substances polluantes a base d'azote et de carbone - Google Patents

Reduction de substances polluantes a base d'azote et de carbone Download PDF

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Publication number
WO1987002023A1
WO1987002023A1 PCT/US1986/002090 US8602090W WO8702023A1 WO 1987002023 A1 WO1987002023 A1 WO 1987002023A1 US 8602090 W US8602090 W US 8602090W WO 8702023 A1 WO8702023 A1 WO 8702023A1
Authority
WO
WIPO (PCT)
Prior art keywords
urea
process according
effluent
solution
hexamethylenetetramine
Prior art date
Application number
PCT/US1986/002090
Other languages
English (en)
Inventor
Wayne E. Bowers
Original Assignee
Fuel Tech, Inc.
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
Priority claimed from US06/906,671 external-priority patent/US4751065A/en
Application filed by Fuel Tech, Inc. filed Critical Fuel Tech, Inc.
Priority to DE1986906208 priority Critical patent/DE237568T1/de
Publication of WO1987002023A1 publication Critical patent/WO1987002023A1/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
    • B01D53/54—Nitrogen compounds
    • B01D53/56—Nitrogen oxides

Definitions

  • the present invention relates to improvements in the combustion of carbonaceous fuels, and more particularly to improvements in firing boilers with reduced emissions of carbon- and nitrogen-based pollutants.
  • Carbonaceous fuels burn more completely, with reduced emissions of carbon monoxide and unburned hydrocarbons, at oxygen concentrations and combustion air/fuel ratios which permit optimized high flame temperatures.
  • these temperatures are above 2000°F and typically from about 2200°F to 3000°F.
  • thermal NO — the temperatures being so high that free radicals of nitrogen and oxygen are formed and chemically combine as nitrogen oxides (NO A).
  • the flame temperature can be lowered to reduce NO A formation by the use of large excesses of air or fuel, or a hybrid of both processes known as staged combustion.
  • these approaches create excessive carbon-based pollutants.
  • Pacztowski discloses a more detailed, controlled two-stage catalytic system.
  • the operating temperatures for the second catalytic stage where ammonia is utilized are preferably within the range of from 275°F to 900°F. This process and that of Jones et al unfortunately depend on the use of catalysts which create additional costs in terms of initial investment and servicing requirements.
  • Lyon discloses a non-catalytic system for reducing nitrogen monoxide (NO) in a combustion effluent.
  • Lyon discloses that ammonia and specified ammonia precursors, including ammonium carbonate also disclosed by Jones, et al , or their aqueous solutions, can be injected into the effluent, for mixing with the nitrogen monoxide at a temperature within the range of 1600°F to 2000°F.
  • a reducing agent such as hydrogen gas or various hydrocarbons, can be mixed with the effluent to permit the reduction reaction to occur at temperatures as low as 1300°F, thereby assuring avoidance of high temperature oxidation of ammonia to nitrogen monoxide.
  • Lyon points out that at temperatures above 2000°F, the use of ammonia was counterproductive — increasing NO rather than decreasing it.
  • Williamson discloses the purification of acid gas-containing streams at low temperatures approaching ambient. Williamson discloses contacting the gas stream with an amine vapor in sufficient concentration such that its partial pressure is at least 5% of the total pressure of the gas stream. This system thus requires large amounts of the treating gas and requires equipment for separating that gas from the effluent upon completing the treatment.
  • the present invention provides a process for reducing the concentration of nitrogen oxides in an oxygen-rich effluent from the combustion of a carbonaceous fuel.
  • the process comprises injecting a solution comprising at least one additive compound selected from the group consisting of guanidine, guanidine carbonate, biguanide, guanylurea sulfate, melamine, dicyandiamide, calcium cyanamide, biuret, ljl'-azobisformamide, methylol urea, methylol urea-urea condensation product, dimethylol urea, methyl urea, dimethyl urea, and hexamethylene ⁇ tetramine, into said effluent.
  • the temperature of the effluent at the point of injection, the concentration of the additive compound in the solution, and the size of the droplets in the dispersion, are selected to achieve reduction in nitrogen oxide levels in the effluent.
  • a preferred embodiment of the invention provides for introducing an aqueous solution of hexamethylenetetramine and urea. Injection is preferably done at a plurality of spaced positions and at a uniform droplet size within the range of from about 10 to about 10,000 microns Sauter mean diameter. Variations of particle sizes within this broad range have been found effective to achieve uniform mixing of the additive compound with the effluent gas at a temperature in excess of 1300°F. For the purposes of this description, all temperatures herein are measured using an unshielded K-type thermocouple. Droplet sizes are determined with a Malvern 2200 instrument, utilizing a Franhofer diffraction, laser-based system. And, unless otherwise indicated, all parts and percentages are based on the weight of the composition at the particular point of reference.
  • urea and materials such as ammonium carbonate, ammonium oxalate, ammonia, hydrazine, ammonium hydroxide, and various amines can be employed with the named additive compounds.
  • Aqueous solutions are preferred according to the present invention due to their economy and can be employed with suitable effectiveness in most situations.
  • the effective solutions will vary from saturated to dilute. While water will be an effective solvent for most applications, there are instances where other solvents may be advantageous in combination with water.
  • the temperature of the effluent will have an influence on the concentration of the solution. At temperatures of from about 1300°F to about 2000°F, the solution will tend to operate effectively at high concentration, e.g., from 25 to 40 weight percent. On the other hand, at temperatures in excess of 2000°F, the solution will tend toward very dilute solutions. At these high temperatures, the water may comprise greater than 80%, 85% or 90% by weight of the solution, with the additive compound comprising as low as from about 0.5 to about 10% by weight of the solution.
  • hexamethylene- tetr-amine is utilized to a greater extent than urea, being almost totally consumed during its interaction with NO A under proper conditions. It is further surprising that, when used in combination with urea, hexamethylenetetramine actually increases the utilization of the urea in reducing NO .A. Thus, hexamethylenetetramine is an enhancer for urea utilization in addition to being a superior NO A reducing agent in its own right.
  • n.amed additive compounds are employed as NO A. reduction optimization and economics dictate.
  • hexamethylene ⁇ tetramine will be present in an amount of at least about 25% based on the combined weight of it and the other active NO A reducer such as urea.
  • Weight ratios of hexamethylenetetramine to urea of from about 1:3 to 3:1 are exemplary.
  • the solution of additive compound will be dispersed uniformly within the effluent gas stream at a point where the effluent is at a temperature above 1300°F, and preferably above 1500°F.
  • Large industrial boilers of the type employed for utility power plants and other large facilities will typically be water jacketted and have access only at limited points. In the most typical situation, the boiler interior can be accessed only in the area of the flame and at an area above the fl-ame, where the temperatures at full load are typically within the range of from about 2200°F to about 2600°F. For boilers operating efficiently with gas, the temperature at this point of access will typically fall within the range of from about 2100°F to about
  • the additive compound solutions according to the present invention are preferably injected at a number of spaced points from nozzles which are effective to uniformly form and disperse droplets of the solutions within the flowing effluent stream to achieve uniform mixing.
  • the size of the droplets of solution will be within the range of from about 10 to about 10,000, and preferably within the range of from about 50 to 10,000 microns Sauter mean diameter. At temperatures below 2000°F, droplet sizes of less than 150 microns are quite effective, while at higher temperatures the droplets should be larger, preferably larger than 500 microns.
  • the concentration of the additive compound or compounds within the effluent gas should be sufficient to provide a reduction in nitrogen oxide levels.
  • the additive compound will be employed at ' a molar ratio of nitrogen in the additive compound to the baseline nitrogen oxide level of from about 1 to 10 to 2 to 1, and will more preferably be within the range of from about 1 to 4 to 3 to 2.
  • HMTA hexamethylenetetramine
  • a Babcock & Wilcox 110 megawatt utility boiler was fired with residual fuel oil through ten Peabody burners to achieve 80 megawatt output.
  • a series of medium-to-course droplet forming atomizers were positioned to inject treatment solutions into the effluent which was at an average temperature of about 1600°F. The following runs were made:
  • HMTA hexamethy ⁇ lenetetramine
  • Example 2 The boiler referred to in Example 2 was fired to 108 megawatt output. Treatment solutions were injected into the effluent at an average effluent temperature of about 2100°F. The products of combustion contained a level of NO which equated to about 10 moles per hour. The following runs were made:
  • HMTA hexamethylenetetramine
  • Example 1 The procedure of Example 1 is repeated for the additive compounds and combinations of them set forth in Table 4 below. The temperatures of the effluent, concentration of solutions, and feed rates are changed from Example 1 as indicated in Table 4.

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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)
  • Processing Of Solid Wastes (AREA)

Abstract

Le procédé ci-décrit est destiné à la réduction d'oxydes d'azote dans un effluent provenant de la combustion d'un carburant contenant du carbone dans des conditions riches en oxygène pour réduire au minimum la production de substances polluantes à base de carbone. Une dispersion d'une solution comprenant au moins un composé additif sélectionné parmi le groupe constitué de guanidine, carbonate de guanidine, biguanide, sulphate de guanylurée, mélamine, dicyandiamide, cyanamide de calcium, biuret, 1,1'-azobisformamide, méthylol urée, un produit de condensation urée-méthylol urée, diméthylol urée, méthylurée, diméthyle, et hexaméthylènetétramine, est injectée dans un effluent à une température supérieure à 1.300oF, et de préférence supérieure à 1.500oF. La concentration du composé additif dans la solution, la température de l'effluent au point d'injection, et la taille des gouttelettes dans la dispersion sont sélectionnées pour obtenir une réduction des oxydes d'azote. Lorsque l'urée est utilisée en combinaison avec l'hexaméthylènetétramine, l'efficacité de l'urée est améliorée, en particulier à des températures de 1.800oF et au-dessous.
PCT/US1986/002090 1985-10-04 1986-10-03 Reduction de substances polluantes a base d'azote et de carbone WO1987002023A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
DE1986906208 DE237568T1 (de) 1985-10-04 1986-10-03 Verminderung der stickstoff- und kohlenstoffhaltigen schadstoffe.

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
US78482785A 1985-10-04 1985-10-04
US784,827 1985-10-04
US81153285A 1985-12-20 1985-12-20
US811,532 1985-12-20
US906,671 1986-09-10
US06/906,671 US4751065A (en) 1985-12-20 1986-09-10 Reduction of nitrogen- and carbon-based pollutants

Publications (1)

Publication Number Publication Date
WO1987002023A1 true WO1987002023A1 (fr) 1987-04-09

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Application Number Title Priority Date Filing Date
PCT/US1986/002090 WO1987002023A1 (fr) 1985-10-04 1986-10-03 Reduction de substances polluantes a base d'azote et de carbone

Country Status (3)

Country Link
EP (1) EP0237568A4 (fr)
AU (1) AU6408086A (fr)
WO (1) WO1987002023A1 (fr)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988006487A1 (fr) * 1987-03-06 1988-09-07 Fuel Tech, Inc. Procede de reduction des oxydes d'azote avec reduction au minimum de la production d'autres substances polluantes
US4844878A (en) * 1985-10-04 1989-07-04 Fuel Tech, Inc. Process for the reduction of nitrogen oxides in an effluent
EP0342184A2 (fr) * 1988-05-09 1989-11-15 Waagner-Biro Aktiengesellschaft Procédé d'élimination d'oxydes d'azote par des substances réductrices solides
DE3823848A1 (de) * 1988-07-14 1990-01-18 Sueddeutsche Kalkstickstoff Verfahren zur reduzierung von so(pfeil abwaerts)2(pfeil abwaerts)- und/oder no(pfeil abwaerts)x(pfeil abwaerts)-emissionen bei verbrennungsprozessen
DE3907330A1 (de) * 1989-03-04 1990-09-13 Noell Gmbh Abscheidungsprozess
DE3929554A1 (de) * 1989-09-06 1991-03-07 Sueddeutsche Kalkstickstoff Verfahren zur reduzierung von schadstoff-emissionen bei verbrennungsprozessen
US5017347A (en) * 1987-02-13 1991-05-21 Fuel Tech, Inc. Process for nitrogen oxides reduction and minimization of the production of other pollutants
US5057293A (en) * 1987-02-13 1991-10-15 Fuel Tech, Inc. Multi-stage process for reducing the concentration of pollutants in an effluent
DE4031379A1 (de) * 1990-04-27 1991-10-31 Sueddeutsche Kalkstickstoff Verfahren zur reduzierung von schadstoffemissionen bei verbrennungsprozessen
DE4100645A1 (de) * 1991-01-11 1992-07-16 Hansjoerg Regler Verfahren zur abscheidung von schadstoffen, insbesondere von sauren schadstoffen, aus gasen und abgasen
GR880100134A (el) * 1988-02-29 1994-03-31 Fuel Tech Inc Διαδικασία για την μείωση των οξειδίων αζώτου με ελαχιστοποίηση της παραγωγής άλλων ρυπαντών.
EP0990463A2 (fr) * 1998-09-29 2000-04-05 AGS Jicin a.s. Plaque réactive pour l'élimination d'impurétés gazeuses et procédé pour sa production
US8048390B2 (en) 2006-12-23 2011-11-01 Alzchem Trostberg Gmbh Method for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4719092A (en) * 1985-10-04 1988-01-12 Fuel Tech, Inc. Reduction of nitrogen-based pollutants through the use of urea solutions containing oxygenated hydrocarbon solvents

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3599427A (en) * 1969-09-22 1971-08-17 Ford Motor Co Exhaust gas purification
DD110833A1 (fr) * 1974-05-03 1975-01-12
CA968927A (en) * 1974-10-04 1975-06-10 Ontario Research Foundation Treatment of no2 - containing gas streams
JPS50110490A (fr) * 1974-02-13 1975-08-30
JPS50118877A (fr) * 1974-02-28 1975-09-17
US3988113A (en) * 1973-08-17 1976-10-26 Roberts Arnold L Apparatus for treating engine exhaust gases
DE2630202A1 (de) * 1975-07-05 1977-02-03 Babcock Hitachi Kk Verfahren zum reduzieren von stickoxiden in verbrennungsabgasen
JPS52109866A (en) * 1976-03-11 1977-09-14 Oki Electric Ind Co Ltd Liquid epitaxial growing method
JPS52112273A (en) * 1976-03-18 1977-09-20 Toshiba Corp Scribing method of semiconductor wafer
DE2752918A1 (de) * 1977-11-26 1979-05-31 Saarbergwerke Ag Verfahren zum reinigen von abgasen
US4208386A (en) * 1976-03-03 1980-06-17 Electric Power Research Institute, Inc. Urea reduction of NOx in combustion effluents
DE2926107A1 (de) * 1979-06-28 1981-01-08 Nukem Gmbh Verfahren zur abscheidung von stickstoffoxiden aus gasen
DE3014606A1 (de) * 1980-04-16 1981-10-29 UOP Kavag, Abteilung der UOP Inc. GmbH, 6467 Hasselroth Kontinuierliches verfahren zur reinigung von industrieabgasen mit einem formaldehydgehalt
DE3447616A1 (de) * 1983-12-30 1985-07-11 Skw Trostberg Ag, 8223 Trostberg Mittel und verfahren zur gleichzeitigen entfernung von schwefel- und stickoxiden aus abgasen

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3599427A (en) * 1969-09-22 1971-08-17 Ford Motor Co Exhaust gas purification
US3988113A (en) * 1973-08-17 1976-10-26 Roberts Arnold L Apparatus for treating engine exhaust gases
JPS50110490A (fr) * 1974-02-13 1975-08-30
JPS50118877A (fr) * 1974-02-28 1975-09-17
DD110833A1 (fr) * 1974-05-03 1975-01-12
CA968927A (en) * 1974-10-04 1975-06-10 Ontario Research Foundation Treatment of no2 - containing gas streams
DE2630202A1 (de) * 1975-07-05 1977-02-03 Babcock Hitachi Kk Verfahren zum reduzieren von stickoxiden in verbrennungsabgasen
US4208386A (en) * 1976-03-03 1980-06-17 Electric Power Research Institute, Inc. Urea reduction of NOx in combustion effluents
JPS52109866A (en) * 1976-03-11 1977-09-14 Oki Electric Ind Co Ltd Liquid epitaxial growing method
JPS52112273A (en) * 1976-03-18 1977-09-20 Toshiba Corp Scribing method of semiconductor wafer
DE2752918A1 (de) * 1977-11-26 1979-05-31 Saarbergwerke Ag Verfahren zum reinigen von abgasen
DE2926107A1 (de) * 1979-06-28 1981-01-08 Nukem Gmbh Verfahren zur abscheidung von stickstoffoxiden aus gasen
DE3014606A1 (de) * 1980-04-16 1981-10-29 UOP Kavag, Abteilung der UOP Inc. GmbH, 6467 Hasselroth Kontinuierliches verfahren zur reinigung von industrieabgasen mit einem formaldehydgehalt
DE3447616A1 (de) * 1983-12-30 1985-07-11 Skw Trostberg Ag, 8223 Trostberg Mittel und verfahren zur gleichzeitigen entfernung von schwefel- und stickoxiden aus abgasen

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
CHEMICAL ABSTRACTS, vol. 103, no. 18, 4 November 1985, Columbus, Ohio, US; PETER WEBER: "Composition and Method for Simultaneous Separation of Sulfur Oxides and NitrogenOxides from flue Gases" page 293; column 1; *
CHEMICAL ABSTRACTS, vol. 84, no. 12, 22 March 1976, Columbus, Ohio, US; abstract no. 19119M, JUERGEN GISBIER ET AL: "Detoxification of Waste Gases Containing Nitrogen Oxides" page 345; column 1; *
CHEMICAL ABSTRACTS, vol. 84, no. 4, 26 January 1976, Columbus, Ohio, US; abstract no. 21673W, ALEXANDER LAWSON: "Treatment of Nitrogen Dioxide-Containing Gas Streams" page 303; column 2; *
CHEMICAL ABSTRACTS, vol. 94, no. 26, 29 June 1981, Columbus, Ohio, US; abstract no. 213667A, HEINRICH QUI UMANN: "Separating Nitrogen Oxides from Gases" page 321; column 1; *
CHEMICAL ABSTRACTS, vol. 96, no. 2, 11 January 1982, Columbus, Ohio, US; abstract no. 11125C, LUDWIG HIRCHE ET AL: "Continuous Purification of Industrial Waste Gases Containing Formaldehyde" page 297; column 1; *
See also references of EP0237568A4 *

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4844878A (en) * 1985-10-04 1989-07-04 Fuel Tech, Inc. Process for the reduction of nitrogen oxides in an effluent
US5057293A (en) * 1987-02-13 1991-10-15 Fuel Tech, Inc. Multi-stage process for reducing the concentration of pollutants in an effluent
US5017347A (en) * 1987-02-13 1991-05-21 Fuel Tech, Inc. Process for nitrogen oxides reduction and minimization of the production of other pollutants
GB2225001A (en) * 1987-03-06 1990-05-23 Fuel Tech Inc Process for nitrogen oxices reduction with minimization of the production of other pollutants
WO1988006487A1 (fr) * 1987-03-06 1988-09-07 Fuel Tech, Inc. Procede de reduction des oxydes d'azote avec reduction au minimum de la production d'autres substances polluantes
GB2225001B (en) * 1987-03-06 1991-09-04 Fuel Tech Inc Process for nitrogen oxides reduction with minimization of the production of other pollutants
GR880100134A (el) * 1988-02-29 1994-03-31 Fuel Tech Inc Διαδικασία για την μείωση των οξειδίων αζώτου με ελαχιστοποίηση της παραγωγής άλλων ρυπαντών.
EP0342184A2 (fr) * 1988-05-09 1989-11-15 Waagner-Biro Aktiengesellschaft Procédé d'élimination d'oxydes d'azote par des substances réductrices solides
EP0342184A3 (fr) * 1988-05-09 1990-03-14 Waagner-Biro Aktiengesellschaft Procédé d'élimination d'oxydes d'azote par des substances réductrices solides
DE3823848A1 (de) * 1988-07-14 1990-01-18 Sueddeutsche Kalkstickstoff Verfahren zur reduzierung von so(pfeil abwaerts)2(pfeil abwaerts)- und/oder no(pfeil abwaerts)x(pfeil abwaerts)-emissionen bei verbrennungsprozessen
DE3907330A1 (de) * 1989-03-04 1990-09-13 Noell Gmbh Abscheidungsprozess
EP0416562A1 (fr) * 1989-09-06 1991-03-13 SKW Trostberg Aktiengesellschaft Procédé pour la réduction d'émissions de polluants par procédés de combustion
DE3929554A1 (de) * 1989-09-06 1991-03-07 Sueddeutsche Kalkstickstoff Verfahren zur reduzierung von schadstoff-emissionen bei verbrennungsprozessen
DE4031379A1 (de) * 1990-04-27 1991-10-31 Sueddeutsche Kalkstickstoff Verfahren zur reduzierung von schadstoffemissionen bei verbrennungsprozessen
DE4100645A1 (de) * 1991-01-11 1992-07-16 Hansjoerg Regler Verfahren zur abscheidung von schadstoffen, insbesondere von sauren schadstoffen, aus gasen und abgasen
EP0990463A2 (fr) * 1998-09-29 2000-04-05 AGS Jicin a.s. Plaque réactive pour l'élimination d'impurétés gazeuses et procédé pour sa production
EP0990463A3 (fr) * 1998-09-29 2000-04-12 AGS Jicin a.s. Plaque réactive pour l'élimination d'impurétés gazeuses et procédé pour sa production
US8048390B2 (en) 2006-12-23 2011-11-01 Alzchem Trostberg Gmbh Method for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles
US8652426B2 (en) 2006-12-23 2014-02-18 Alzchem Trostberg Gmbh Use of aqueous guanidinium formate solutions for the selective catalytic reduction of nitrogen oxides in exhaust gases of vehicles

Also Published As

Publication number Publication date
EP0237568A1 (fr) 1987-09-23
AU6408086A (en) 1987-04-24
EP0237568A4 (fr) 1989-01-24

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