CA2081190A1 - Process for the recovery of ammonia from flue gas residues - Google Patents
Process for the recovery of ammonia from flue gas residuesInfo
- Publication number
- CA2081190A1 CA2081190A1 CA002081190A CA2081190A CA2081190A1 CA 2081190 A1 CA2081190 A1 CA 2081190A1 CA 002081190 A CA002081190 A CA 002081190A CA 2081190 A CA2081190 A CA 2081190A CA 2081190 A1 CA2081190 A1 CA 2081190A1
- Authority
- CA
- Canada
- Prior art keywords
- ammonia
- slurry
- flue gas
- dry residue
- water
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/026—Preparation of ammonia from inorganic compounds
-
- 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
- B01D53/58—Ammonia
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
- C01C1/00—Ammonia; Compounds thereof
- C01C1/02—Preparation, purification or separation of ammonia
- C01C1/10—Separation of ammonia from ammonia liquors, e.g. gas liquors
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Analytical Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Biomedical Technology (AREA)
- Environmental & Geological Engineering (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
ABSTRACT OF THE DISCLOSURE
Ammonia is recovered from the residues produced in the purification of flue gases by mixing the dry residues with water and heating. If the aqueous mixture is acidic or neutral, it is made alkaline by addition of alkali. The ammonia, together with steam, is then evaporated from the mixture by heating.
TRS\
Ammonia is recovered from the residues produced in the purification of flue gases by mixing the dry residues with water and heating. If the aqueous mixture is acidic or neutral, it is made alkaline by addition of alkali. The ammonia, together with steam, is then evaporated from the mixture by heating.
TRS\
Description
4273-003-o 2f~?4.1S~) TI~E 0~ TH~ INV~NTI~N
PROCESS FOR THE RECOVERY OF AMMONIA FROM
FLUE GAS RESIDUES
BACXGROUND OF THE INVENTION
Field of the Invention:
The present invention relates to a process for the recovery of ammonia from the residues produced during the purification of flue gases.
Discussion of the Background:
Ammonia or substances which generate ammonia can be added to flue gases from combu~tion plants for elimination of nitrogen oxides (NOx). This ammonia then reacts with the nitrogen oxides in a denitration reaction zone where the nltrogen oxide~ are reduced to elemental nitrogen (N2). In order to reliably achieve complete eliminatlon o~ the nitrogen oxides, an excess o~ ammonia is preferably used.
The excess ammonia is partly adsorbed on solid components in the ~lue gas, ~or example ~ly ash. Some of the ammonia is separated ~rom the ~lue gas in the wet scrubber connected downstream and is produced as a solid ammonium salt, ~or example during drying o~ the scrubbing water from the ~lue gas scrubbing unit, The recovery of the excess ammonia i~ desirable ~or reasons o~ environmental protection and economic efficiency.
o 2~ q.~9~
Various processes are known for the recovery of this ammonia. In CH-A ~73 5~3, the elimination of ammonia from the scrubbing water of a wet scrubbing unit is described.
The water is made alkaline and the ammonia is driven off by stripping with air. This process is not suitable for treating solid residues.
DE-Al 35 26 7S6 describes a process in which ammonia adsorbed on fly ash is desorbed by heating the fly ash. In this case, the fly ash must be heated to at least 300-C.
As a result, in addition to ammonia, acids such as HCl, S02, S03 and the readily volatile metals mercury, cadmium and arsenic are also liberated and m~st be separated by complicated means.
In both of these processes, the recovered ammonia is produced as a mixture with air. This mixture is returned a~ ~econdary air into the combustion plant (boiler), where, as a result o~ the prevailing high temperatures, ammonia can be burnt to give nitrogen oxide~. A~ a result, exactly the opposite of the intended elimination of nitrogen oxides is achieved. I~ reuse of this ammonia is desired, additional expensive purification and combustion processes must be used.
A need continues to exist ~or a proce~s which allows recovery of reusable ammonia from flue gas purification re~idues which is economical and non-polluting.
2~ ~ q.~..9'~) , -3-~ SUMMARY OF THE INVENTION
one object~of the present invent~on is to provide a simple and econDmic process which permits the recovery of reusable ammoni~ both from the fly ash and from other solid residues produced during ~lue gas purification, for example from solid residue from scrubbing water or from dry purification.
This and other objects which will become apparent from the following specification have been achieved by the present process in which dry residues are mixed with water, and optionally alkali compounds, and then heated to produce an ammonia/steam mixture.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A critical aspect of the present invention is the unu~ual step of rewetting a re~idue which has been already drled and/or produced in the dry state, optionally with the ~imultaneou~ addition of alkali compounds, and subsequent heat treatment. In this process, a steam/ammonia mixture ls isolated, which can either be reused as such ar, following condensation, as an alXaline ammonia solution.
The condensed mixture, which is an aqueous ammonia solution, is preferably reused for reductive treatment of the flue gases for elimination of nitrogen oxides.
Since the excess ammonia can be substantially z5 completely recovered by the process according to the (J d..3~aJI~) invention, it can be used in as large an excess as is desired for the elimination of nitrogen oxides.
The process according to the invention can be used to recover ammonia from all residues produced in flue gas purification, such as fly ash, residues of dry flue gas purification and of wet flue gas scrubbing. A residue to be treated according to the invention is preferably present as a dust-dry product.
The process according to the invention is suitable both for residues which are obtained in the purification of flue gases produced from the combustion of fossil fuels, and for residues which are produced in the purification of flue gases from other materials such as domestic or industrial waste. In this case, the ammonia to be recovered can occur in a chemically and/or physically bound form. Such residues are well known in the art.
Re~idues of different origin, for example fly ash and the dust produced in the spray drying of scrubbing water from wet scrubbing of the flue gase~, can be treated together as mixtures. A preferred source is the residue from dust separators of flue gas purification units.
The amount of water to be added to the dry residue can be varied within a wide range, depending on various factors such as the type of dry residue and the desired residual 2S water quantity remaining. The amount of water added should be sufficient to form a slurry with the dry residue. The ~. & ~
amount of water will generally range from about 15 wt.% to about 100 wt.%, preferably about 80-100 wt.%, relative to the dry residue.
If the slurry obtained by adding water to the dry residue is acidic or neutral, it is necessary to add an alkali to increase the pH of the slurry and produce an alkaline slurry. Suitable alkali compounds which may be used include alkali and alkaline earth metal oxides and hydroxides, and for economic reasons, pre~erably calcium hydroxide, calcium oxide, sodium hydroxide or mixtures of these. If the dry residues already contain sufficient alXali, the addition of alkali is unnecessary. This is generally the case when residues from dry flue gas purification are used. If calcium oxide (kilned lime) is used as the alkali, the heat of its reaction with water can be used alone or together with an additional heat source ~or evaporation o~ the water and for driving off the ammonia.
When used, the alkali is generally added in an amount 20 of about 1-3 times, preferably about 1.5-2 times the stoichiometric amount of ammonia which is present in the dry residue. One having ordinary skill in the art can readily determine the amount of ammonia present in the dry residue using known analytical methods. The amount of alkali corre~ponding to 1-3 times the stoichiometric amount 2r~
of the ammonia present in the dry residue can then be calculated from these initial determinations.
Heating and evaporation of the mixture are carried out with any suitable evaporator, preferably in a thin-film evaporator which is heated k,y steam. The demineralized water produced during this evaporation process can be recirculated to wet the dry residue, used as cooling water, etc.
The final water content of the remaining ammonia-free residue can be adjusted as desired. Heating and evaporation of the steam/ammonia mixture results in removal of a portion of the water initially added to the dry residue. Additional water can be removed from the ammonia ~ree residue by continued heating and evaporation. As a result of a low water content, dust emission from the prOCe88 i5 reducsd and a volume reduction is achieved.
Legal provisions regarding the minimum water content exist, ~or example, in the Federal Republic of Germany.
The steam/ammonia which i~ removed by heating and evaporation i5 recovered and may be dehydrated using known methods to obtain purified ammonia. Alternatively, the steam/ammonia mixture may be recycled and added to the flue gas ~or elimination of nitrogen oxides as described above.
If desired, the steam/ammonia mixture may be condensed u~ing conventional equipment and this condensed liguid mixture recycled to the flue gas for elimination of nitrogen oxides.
The present invention provides an economical and efficient means of recovering ammonia added to flue gas streams for the purpose of removing nitrogen oxides. The efficient recovery of ammonia allows one to add large amounts of ammonia to the flue gas stream thereby eliminating substantially all nitrogen oxides without the risk that large amounts of ammonia in flue gas residues will be released to the environment. Ammonia is economically recovered and may be reused in the denitration process to remove nitrogen oxides without environmental problems.
Other features of the invention will become apparent in the course of the ~ollowing descriptions of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.
EXAMPLES
Exam~les 1 to 11 Ammonia was reco~ered from the dry residue of scrubbing water from a flue gas wet scrubbing unit produced in a spray dryer. ~he dry residue contained 7 g of ammonia per 100 g o~ dry residue. 80 or 100 g of water and 1.3 to 2.0 equivalents of Cao, based on the amount o~ ammonia, were added to each 100 g of dry residue. The mixture of -8- 2r~
dry residue, water and CaO was placed in a thin-film evaporator, where a portion of the water was evaporated.
At the same time, a portion of the am~onia, present in the dry residue in the form of ammonium salts was liberated, recovered and resupplied for denitration.
The experimental conditions and the results are compiled in the followinq table.
Obviously, numerous modifications and variations of the present invention are possible in liqht of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
2~
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L~ e N e _ _ __ _ _ _ ~ ~1
PROCESS FOR THE RECOVERY OF AMMONIA FROM
FLUE GAS RESIDUES
BACXGROUND OF THE INVENTION
Field of the Invention:
The present invention relates to a process for the recovery of ammonia from the residues produced during the purification of flue gases.
Discussion of the Background:
Ammonia or substances which generate ammonia can be added to flue gases from combu~tion plants for elimination of nitrogen oxides (NOx). This ammonia then reacts with the nitrogen oxides in a denitration reaction zone where the nltrogen oxide~ are reduced to elemental nitrogen (N2). In order to reliably achieve complete eliminatlon o~ the nitrogen oxides, an excess o~ ammonia is preferably used.
The excess ammonia is partly adsorbed on solid components in the ~lue gas, ~or example ~ly ash. Some of the ammonia is separated ~rom the ~lue gas in the wet scrubber connected downstream and is produced as a solid ammonium salt, ~or example during drying o~ the scrubbing water from the ~lue gas scrubbing unit, The recovery of the excess ammonia i~ desirable ~or reasons o~ environmental protection and economic efficiency.
o 2~ q.~9~
Various processes are known for the recovery of this ammonia. In CH-A ~73 5~3, the elimination of ammonia from the scrubbing water of a wet scrubbing unit is described.
The water is made alkaline and the ammonia is driven off by stripping with air. This process is not suitable for treating solid residues.
DE-Al 35 26 7S6 describes a process in which ammonia adsorbed on fly ash is desorbed by heating the fly ash. In this case, the fly ash must be heated to at least 300-C.
As a result, in addition to ammonia, acids such as HCl, S02, S03 and the readily volatile metals mercury, cadmium and arsenic are also liberated and m~st be separated by complicated means.
In both of these processes, the recovered ammonia is produced as a mixture with air. This mixture is returned a~ ~econdary air into the combustion plant (boiler), where, as a result o~ the prevailing high temperatures, ammonia can be burnt to give nitrogen oxide~. A~ a result, exactly the opposite of the intended elimination of nitrogen oxides is achieved. I~ reuse of this ammonia is desired, additional expensive purification and combustion processes must be used.
A need continues to exist ~or a proce~s which allows recovery of reusable ammonia from flue gas purification re~idues which is economical and non-polluting.
2~ ~ q.~..9'~) , -3-~ SUMMARY OF THE INVENTION
one object~of the present invent~on is to provide a simple and econDmic process which permits the recovery of reusable ammoni~ both from the fly ash and from other solid residues produced during ~lue gas purification, for example from solid residue from scrubbing water or from dry purification.
This and other objects which will become apparent from the following specification have been achieved by the present process in which dry residues are mixed with water, and optionally alkali compounds, and then heated to produce an ammonia/steam mixture.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A critical aspect of the present invention is the unu~ual step of rewetting a re~idue which has been already drled and/or produced in the dry state, optionally with the ~imultaneou~ addition of alkali compounds, and subsequent heat treatment. In this process, a steam/ammonia mixture ls isolated, which can either be reused as such ar, following condensation, as an alXaline ammonia solution.
The condensed mixture, which is an aqueous ammonia solution, is preferably reused for reductive treatment of the flue gases for elimination of nitrogen oxides.
Since the excess ammonia can be substantially z5 completely recovered by the process according to the (J d..3~aJI~) invention, it can be used in as large an excess as is desired for the elimination of nitrogen oxides.
The process according to the invention can be used to recover ammonia from all residues produced in flue gas purification, such as fly ash, residues of dry flue gas purification and of wet flue gas scrubbing. A residue to be treated according to the invention is preferably present as a dust-dry product.
The process according to the invention is suitable both for residues which are obtained in the purification of flue gases produced from the combustion of fossil fuels, and for residues which are produced in the purification of flue gases from other materials such as domestic or industrial waste. In this case, the ammonia to be recovered can occur in a chemically and/or physically bound form. Such residues are well known in the art.
Re~idues of different origin, for example fly ash and the dust produced in the spray drying of scrubbing water from wet scrubbing of the flue gase~, can be treated together as mixtures. A preferred source is the residue from dust separators of flue gas purification units.
The amount of water to be added to the dry residue can be varied within a wide range, depending on various factors such as the type of dry residue and the desired residual 2S water quantity remaining. The amount of water added should be sufficient to form a slurry with the dry residue. The ~. & ~
amount of water will generally range from about 15 wt.% to about 100 wt.%, preferably about 80-100 wt.%, relative to the dry residue.
If the slurry obtained by adding water to the dry residue is acidic or neutral, it is necessary to add an alkali to increase the pH of the slurry and produce an alkaline slurry. Suitable alkali compounds which may be used include alkali and alkaline earth metal oxides and hydroxides, and for economic reasons, pre~erably calcium hydroxide, calcium oxide, sodium hydroxide or mixtures of these. If the dry residues already contain sufficient alXali, the addition of alkali is unnecessary. This is generally the case when residues from dry flue gas purification are used. If calcium oxide (kilned lime) is used as the alkali, the heat of its reaction with water can be used alone or together with an additional heat source ~or evaporation o~ the water and for driving off the ammonia.
When used, the alkali is generally added in an amount 20 of about 1-3 times, preferably about 1.5-2 times the stoichiometric amount of ammonia which is present in the dry residue. One having ordinary skill in the art can readily determine the amount of ammonia present in the dry residue using known analytical methods. The amount of alkali corre~ponding to 1-3 times the stoichiometric amount 2r~
of the ammonia present in the dry residue can then be calculated from these initial determinations.
Heating and evaporation of the mixture are carried out with any suitable evaporator, preferably in a thin-film evaporator which is heated k,y steam. The demineralized water produced during this evaporation process can be recirculated to wet the dry residue, used as cooling water, etc.
The final water content of the remaining ammonia-free residue can be adjusted as desired. Heating and evaporation of the steam/ammonia mixture results in removal of a portion of the water initially added to the dry residue. Additional water can be removed from the ammonia ~ree residue by continued heating and evaporation. As a result of a low water content, dust emission from the prOCe88 i5 reducsd and a volume reduction is achieved.
Legal provisions regarding the minimum water content exist, ~or example, in the Federal Republic of Germany.
The steam/ammonia which i~ removed by heating and evaporation i5 recovered and may be dehydrated using known methods to obtain purified ammonia. Alternatively, the steam/ammonia mixture may be recycled and added to the flue gas ~or elimination of nitrogen oxides as described above.
If desired, the steam/ammonia mixture may be condensed u~ing conventional equipment and this condensed liguid mixture recycled to the flue gas for elimination of nitrogen oxides.
The present invention provides an economical and efficient means of recovering ammonia added to flue gas streams for the purpose of removing nitrogen oxides. The efficient recovery of ammonia allows one to add large amounts of ammonia to the flue gas stream thereby eliminating substantially all nitrogen oxides without the risk that large amounts of ammonia in flue gas residues will be released to the environment. Ammonia is economically recovered and may be reused in the denitration process to remove nitrogen oxides without environmental problems.
Other features of the invention will become apparent in the course of the ~ollowing descriptions of exemplary embodiments which are given for illustration of the invention and are not intended to be limiting thereof.
EXAMPLES
Exam~les 1 to 11 Ammonia was reco~ered from the dry residue of scrubbing water from a flue gas wet scrubbing unit produced in a spray dryer. ~he dry residue contained 7 g of ammonia per 100 g o~ dry residue. 80 or 100 g of water and 1.3 to 2.0 equivalents of Cao, based on the amount o~ ammonia, were added to each 100 g of dry residue. The mixture of -8- 2r~
dry residue, water and CaO was placed in a thin-film evaporator, where a portion of the water was evaporated.
At the same time, a portion of the am~onia, present in the dry residue in the form of ammonium salts was liberated, recovered and resupplied for denitration.
The experimental conditions and the results are compiled in the followinq table.
Obviously, numerous modifications and variations of the present invention are possible in liqht of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
2~
V ~ ~ N ------ N 1'7 ~I a~ ~0 ~ o Ll~ O~ ~ ~ In ~ t~l ~ ~i 1~ CO I
~ u~ u~ ~o ~n ~D ~ CO U) ~ ~ I~
Co _ _ _ _ _ _ _ _ _ .~ CD O ~ ~1 t~ N
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~ t~ ~r ~ ('~ ~i u) O ~ O ~1 ~
:~ ~ ~ u~ o~ ~ ~r ~o ,~ ~ In ~
~ _ _ _ _ _ _ _ _ _ _ I
~ ~ ~ ~ ~ ~D ~ O O CO O O O l ~ ~ o a~ ~1 ~ 1~ o o CD O O O l l C 1~ 1~ ~.0 ~O 0 t` 1~ d' t` t` 1~
Co~ _ _ _ _ _ _ _ _ _ _ l ~ ~ t'l ~ t'~ In In 1~ o o o o I
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_ _ _ _ _ _ _ _ _ _ a~
L~ e N e _ _ __ _ _ _ ~ ~1
Claims (17)
1. A process for the recovery of ammonia from dry residues, comprising the steps of:
mixing water and a dry residue containing ammonium salts to form a slurry, heating and evaporating steam and ammonia from said slurry, and recovering said steam and ammonia
mixing water and a dry residue containing ammonium salts to form a slurry, heating and evaporating steam and ammonia from said slurry, and recovering said steam and ammonia
2. The process of Claim 1, wherein only a portion of the water in the slurry is evaporated and removed.
3. The process of Claim 1, wherein said dry residue is the residue of scrubbing water from a wet scrubbing flue gas purification unit.
4. The process of Claim 1, wherein said residue is the residue of a dust separator of a flue gas purification unit.
5. The process of Claim 1, wherein said slurry is acidic or neutral, further comprising adding an alkali compound to said slurry.
6. The process of Claim 5, wherein said alkali compound is selected from the group consisting of alkali and alkaline earth metal oxides and hydroxides.
7. The process of Claim 5, wherein said alkali compound is calcium oxide, calcium hydroxide, sodium hydroxide or mixtures thereof.
8. The process of Claim 5, wherein said alkali compound is added in an amount of about 1-3 times the stoichiometric amount of ammonia in said dry residue.
9. The process of Claim 5, wherein said alkali compound is added in an amount of about 1.5-2 times the stoichiometric amount of ammonia present is said dry residue.
10. The process of Claim 1, wherein said slurry is heated in an evaporator.
11. The process of Claim 10, wherein said evaporator is a thin-film evaporator.
12. The process of Claim 1, wherein 15 to 100 wt.%
water, based on said dry residue, is mixed with said dry residue.
water, based on said dry residue, is mixed with said dry residue.
13. The process of Claim 5, wherein calcium oxide is added to said slurry in an amount of about 2 times the stoichiometric amount of ammonia present in said dry residue, and said heating and evaporating is conducted using the heat of reaction of said calcium oxide with water in said slurry, without addition of external heat.
14. The process of Claim 1, further comprising condensing said evaporated steam and ammonia.
15. The process of Claim 1, further comprising recycling said evaporated steam and ammonia to a denitration zone where ammonia is added to the flue gas from a combustion plant.
16. In a process for reductively removing nitrogen oxides from the flue gas of a combustion plant by adding ammonia to the flue gas to reduce nitrogen oxides, where the flue gas is purified to form a dry residue containing ammonium salts, the improvement comprising:
recovering ammonia from the dry residues by mixing water and the dry residue containing ammonium salts to form a slurry, heating and evaporating steam and ammonia from said slurry, and recovering said steam and ammonia.
recovering ammonia from the dry residues by mixing water and the dry residue containing ammonium salts to form a slurry, heating and evaporating steam and ammonia from said slurry, and recovering said steam and ammonia.
17. The process of Claim 16, wherein said slurry is acidic or neutral, further comprising adding an alkali compound to said slurry.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CH311391A CH681719A5 (en) | 1991-10-24 | 1991-10-24 | |
| CH03113/91-9 | 1991-10-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2081190A1 true CA2081190A1 (en) | 1993-04-25 |
Family
ID=4248901
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002081190A Abandoned CA2081190A1 (en) | 1991-10-24 | 1992-10-22 | Process for the recovery of ammonia from flue gas residues |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0538647A1 (en) |
| JP (1) | JPH07187660A (en) |
| CA (1) | CA2081190A1 (en) |
| CH (1) | CH681719A5 (en) |
| NO (1) | NO924100L (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU3105799A (en) * | 1998-03-26 | 1999-10-18 | Board Of Control Of Michigan Technological University | Method for removal of ammonia from fly ash |
| US6077494A (en) * | 1999-02-24 | 2000-06-20 | Separation Technologies, Inc. | Method for removing ammonia from ammonia contaminated fly ash |
| EP1155732A1 (en) * | 2000-05-15 | 2001-11-21 | Reatec GmbH | Process for treating residues from flue gas purification and/or flue gas desulphurisation plant |
| CN103130244A (en) * | 2011-11-28 | 2013-06-05 | 昆山科技大学 | Method for recovering ammonia in exhaust gas containing organic metal or dust |
| US11453951B1 (en) * | 2021-06-07 | 2022-09-27 | United Arab Emirates University | Method for ammonia recovery from contaminated water including solvay effluent and aqueous solutions |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3711503A1 (en) * | 1987-04-04 | 1988-10-13 | Steinmueller Gmbh L & C | Ammonia removal from combustion ash esp. fly ash - using small amt. of water, and drying under alkaline conditions with reduced drying energy |
| JPS6411688A (en) * | 1987-07-02 | 1989-01-17 | Kawasaki Heavy Ind Ltd | Treating method for ash with ammonium salt |
| DE3815963A1 (en) * | 1988-05-10 | 1989-11-23 | Knauf Westdeutsche Gips | Process and apparatus for removing ammonia from fly ash |
-
1991
- 1991-10-24 CH CH311391A patent/CH681719A5/de not_active IP Right Cessation
-
1992
- 1992-09-26 EP EP92116513A patent/EP0538647A1/en not_active Withdrawn
- 1992-10-22 NO NO92924100A patent/NO924100L/en unknown
- 1992-10-22 CA CA002081190A patent/CA2081190A1/en not_active Abandoned
- 1992-10-26 JP JP32838392A patent/JPH07187660A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07187660A (en) | 1995-07-25 |
| EP0538647A1 (en) | 1993-04-28 |
| NO924100D0 (en) | 1992-10-22 |
| NO924100L (en) | 1993-04-26 |
| CH681719A5 (en) | 1993-05-14 |
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