GB2152915A - Multi-stage method of binding gaseous harmful substances contained in flue gases - Google Patents
Multi-stage method of binding gaseous harmful substances contained in flue gases Download PDFInfo
- Publication number
- GB2152915A GB2152915A GB08428014A GB8428014A GB2152915A GB 2152915 A GB2152915 A GB 2152915A GB 08428014 A GB08428014 A GB 08428014A GB 8428014 A GB8428014 A GB 8428014A GB 2152915 A GB2152915 A GB 2152915A
- Authority
- GB
- United Kingdom
- Prior art keywords
- additives
- additive
- amount
- flue
- harmful substances
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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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
- B01D53/68—Halogens or halogen 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
- B01D53/48—Sulfur compounds
- B01D53/50—Sulfur oxides
- B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES
- F23J7/00—Arrangement of devices for supplying chemicals to fire
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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)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Treating Waste Gases (AREA)
Abstract
A method of reducing the gaseous harmful substances, such as SOx, fluorine or chlorine compounds, resulting during the combustion of fuels by introducing additives by means of a carrier fluid into the radiation chamber, following on the combustion chamber, wherein the additives are introduced simultaneously into the radiation chamber in at least two, preferably in three stages arranged one behind the other. <IMAGE>
Description
SPECIFICATION
Multi-stage method of binding gaseous harmful substances contained in flue gases
The invention relates to a method of reducing the gaseous harmful substances, such as SOx, fluorine or chlorine compounds for example, resulting during the combustion of fuels with a high calorific value, by introducing additives, by means of a carrier fluid, into the radiation chamber, following on the combustion chamber, of a steam generating plant.
During the combustion of fuels with a high calorific value, particularly lignite or mineral coals, flue gases result which contain gaseous harmful substances such as sulphur oxides, fluorine or chlorine compounds, which pollute the environment to a great extent. Methods of binding these harmful substances are known wherein the flue gases are treated with additives. Since the reaction capacity of the additives added to the flue gases is dependent on temperature, separate additives are used in each case for the high, medium and low temperature ranges of the flue gas in order to achieve the optimum reaction. The dependence on temperature with regard to the reaction capacity in turn determines the feed point for the additive.
Fundamentally, it is possible to supply the additives directly with the fuel or to introduce these separately into the combustion chamber of a steam generating plant and to bring them into contact with the flue gas. Methods are also known wherein the treatment of flue gas by means of additives is effected outside the steam generating plant. In contrast to lignite, the additives cannot be added directly to the fuel during the combustion of mineral coals because in this case the flame temperature is above the sintering temperature of the additive. As a result, the additives become incapable of reaction. Air or water for the ii ecrion is preferably used as a carrier medium for the introduction of additives into the radiation chamber as well as in the case of external flue-gas treatment.
It is common to all these known methods that there is an inadequately thorough mixing of harmful substances and additives in the whole treatment area and so the binding of harmful substances is limited. In the case of an external treatment of the flue gas by means of additives, additional reaction chambers must be made available outside the steam generator. During the addition of the additive to the fuel, it is a disadvantage that agglomerations occur as a result of the thorough mixing between additive and the unburned material in the combustion chamber 5r in the flame region and consequently sintering occurs so that some of the additive is no longer available for the following binding of the harmful gases.
It is therefore the object of -the invention to develop further a method of reducing the gaseous harmful substances resulting during the combustion of fuels with a high calorific value, by introducing additives, by means of a carrier fluid, into the radiation chamber, following on the combustion chamber, of a steam generating plant, in such a manner that an increase in the binding of harmful substances is possible with optimum utilization of the amount of added additive.
In order to solve this problem, a method is proposed according to the invention, which is characterised in that the additives are introduced simultaneously into the radiation chamber in at least two, preferably in three stages arranged one behind the other.
As a supporting measure for the thorough mixing of the additives with the harmful gases in the whole treatment area, the invention provides that the additives are introduced into the radiation chamber via a plurality of feed positions at the circumferential side in each stage.
In order to avoid sintering and to ensure an adequate dwell time of the additive with the harmful substances in the flue gas, the invention teaches that the introduction of additives is effected in a temperature range from 1500 to 8000C inside the radiation chamber.
In order to increase the efficiency of the binding of harmful substances further, the invention proposes that additives which provide optimum reaction conditions in each case for the binding of harmful substances for the flue-gas temperature prevailing in the region of a stage are introduced into the individual stages.
A further development of the invention consists in that a liquid stream of material preferably serves as a carrier fluid for the stages in the high-temperature range and a gaseous stream of material for the other stages. The method according to the invention is also suitable for the use of powdery additives.
Furthermore, it is proposed that the amount of additive for the last stage downstream should be regulated via the SOx concentration of the flue gas which has already been purified and the amount of additive for the remaining stages should be regulating depending on the load, the load signal being formed in known manner from the central command variable of the steam generator, such as amount of fuel or steam and the sulphur content of the fuel for example.
As an alternative to this, the invention provides that the amount of additive added in each stage is regulated depending on the load, the load signal being formed in known manner from the central command variable of the steam generator, such as amount of fuel or steam and the sulphur content of the fuel for example, and the SOx concentration of the purified flue gas is returned to the particular additive amount regulation as a primary correction quantity and the flue-gas temperature prevailing in the region of a stage as a secondary correction quantity and they influence the desired value, which is dependent on load, in such a manner that the amount of additive is regulated via the degree of desulphurization of the additive, which is dependent on temperature, while adhering to the limiting value of the SOx emission as the desired value of the primary correction quantity.
Besides this, it is possible, according to the in vention, for a component amount of the solid separated out of the flue gas originating from the actual combustion process to be returned to the radiation chamber, with or without the addition of unused additives, the introduction being effected in a region with a flue-gas temperature below the decomposition temperature of the reaction producs of additives and harmful gases.
The advantages which are achieved with the invention consist in that, on the one hand, as a result of the simultaneous addition of additives in a plurality of stages to the radiation chamber of a steam generator, an increased binding of harmful substances becomes possible with a simultaneous reduction in the amount of additives in comparison with the known methods. This is achieved as a result of the fact that by dividing the whole stream of additives into the component streams in various stages downstream arranged one behind the other and as a result of a plurality of feed positions at the circumferential side in one stage or plane, a more effectively thorough mixing of additives and harmful gases is achieved.As a result of the measure of regulating the amount of additive in the last stage downstream via the SOx concentration of the flue gas already treated, it is possible for the operator of a steam generating plant, particularly an old plant, to adhere to the particular limiting emission value laid down for this. This acts as an advantage above all if the space necessary for a wet flue-gas desulphurizing installation is not available; with the method according to the invention, the nozzles for the introduction of the additive are the only important constructional alterations which have to be made to the steam generator.An important characteristic of the invention results from the combination of the multiple-stage introduction of the additive and the possibility of adding additives in the individual stages, in each case, which provide optimum reaction conditions for binding the harmful substances in each region of the treatment area, for the flue-gas temperature prevailing here.
It is a further advantage to use liquid carrier fluid in the higher flue-gas temperature range and gaseous carrier fluid with a lower flue-gas temperature. As a result, a local cooling down of the fluegas in the vicinity of the additives is achieved in the high-temperature region as a result of the evaporation of the carrier fluid. Thus there is no
longer a risk of sintering which is accompanied by
a better utilization of additives in this hot temperature region. As a result of the possibility of recycling solids which contain additives which have not yet reacted but are capable of reaction, an additional utilization and the associated reduction in the amount of additive needed is achieved.At the same time, a decomposition of the harmful substances already bound, which is inevitable with the
known methods, is prevented as a result of the fact that the solids are introduced into the radiation
chamber in a temperature range below the decom
position temperature of these reaction products.
The method according to the invention is ex
plained in more detail with reference to an exam ple of embodiment illustrated in the Figure.
The Figure shows a steam generating plant 1, from which the flue gases resulting in the step molten ash chamber 2 flow through the radiation chamber 3 and convective section 4 and are then released into the atmosphere via an air preheater and an E filter. In order to bind the harmful substances contained in the flue gases, the additives are fed into the radiation chamber 3 via three stages 5, 6 and 7 and brought into contact with the flue gas. The individual stages or planes should be disposed in a temperature range inside the radiation chamber of a maximum of 1,500 C to a minimum of 8000C in order to avoid sintering of the additive in the high-temperature range and inactivity of the additive in the low-temperature range.
According to the example of embodiment, various additives are used in the individual planes and are adapted, with regard to their activity, to the particular flue-gas temperature prevailing. The storage of the additives is effected in the containers 8, 9 and 10 from where they are conveyed to the particular feed positions by means of pneumatic conveying. A liquid, such as water for example, can be used selectively as carrier fluid in the lowest plane 5 downstream. As a result, a cooling down of the flue-gas is achieved in the hot-temperature region as a result of evaporation so that here the risk of sintering of the additives is largely avoided. The arrangement of a plurality of feed positions present at the circumferential side of the radiation chamber, in one plane serves as a supporting measure for the homogenizing of additives and harmful substances in the whole treatment area.In order to adhere to the permissible limiting emission value, according to the example of embodiment, the SOx content of the flue-gas already treated is returned as a correction quantity to the regulation 11 for the amount of additive to be supplied from silo 10, the desired value for the amount of additives to be supplied from the silos 8 and 9 being controlled depending on load. In this case, the load signal is formed from the central command variable of a steam generating plant, such as amount of fuel or steam and the sulphur content of the fuel for example.As an alternative to this simple regulation, it is also possible to return the SOx concentration of the flue gas already purified as a primary correction quantity and the signal for the flue-gas temperature prevailing in a plane as a secondary correction quantity to the regulation of the amount of additive in a stage, depending on load. The processing of the signals is effected in such a manner that, while adhering to the limiting value of SOx emission as a desired value for the primary correction quantity, the amount of additive to be fed in is additionally regulated via the degree of desulphurization of the additive, which is dependent on temperature. In this case, the fact is taken into consideration that the reactivity of an additive with the harmful substances from the flue gas is dependent on temperature. The desired value depending on load for the amount to be fed in is determined as in the abovementioned simple regulation. With such an exten sive regulation, a further increase in the degree of desulphurization can be achieved. As a result of the conduct of the method according to the invention, that is to say multi-stage treatment of the flue gas inside the radiation chamber of a steam generating plant in combination with the use of separate additives in various stages as well as the possibility of using gaseous or liquid carrier fluids for the injection of the additives, a considerably greater effectiveness of the binding of harmful substances and more effective utilization of the additive supplied is achieved in the steam generator than is possible with the known methods.
Claims (10)
1. A method of reducing the gaseous harmful substances, such as SOx, fluorine or chlorine compounds for example, resulting during the combustion of fuels with a high calorific value, by introducing additives, by means of a carrier fluid, into the radiation chamber, following on the combustion chamber, of a steam generating plant, characterised in that additives are introduced simultaneously into the radiation chamber in at least two, preferably in three stages, arrranged one behind the other.
2. A method as claimed in Claim 1, characterised in that, in each stage, the additives are introduced into the radiation chamber via a plurality of feed positions at the circumferential side.
3. A method as claimed in Claims 1 or 2, characterised in that the introduction of additives is effected in a temperature range, inside the radiation chamber, of 1500 to 800 C.
4. A method as claimed in Claims 1 to 3, characterised in that, in the individual stages, additives are fed in which provide optimum reaction conditions in each case for the binding of harmful substances for the flue-gas temperature prevailing in the region of one stage.
5. A method as claimed in Claims 1 to 4, characterised in that a liquid stream of material preferably serves as carrier fluid for the stages in the high-temperature range and a gaseous stream of material for the other stages.
6. A method as claimed in Claims 1 to 5, characterised by the use of powdery additives.
7. A method as claimed in Claims 1 to 6, characterised in that the amount of additive for the last stage downstream is regulated via the SOx concentration of the flue gas already purified and the amounts of additive for the remaining stages are regulated depending on the load, the load signal being formed in known manner from the central command variable of the steam generator, such as amount of fuel or steam and the sulphur content of the fuel for example.
8. A method as claimed in Claims 1 to 6, characterised in that the amount of additive added in each stage is regulated depending on the load, the load signal being formed in known manner from the central command variable of the steam generator, such as amount of fuel or steam and the sulphur content of the fuel for example, and the SOx concentration of the purified flue gas is returned to the particular additive amount regulation as a primary correction quantity and the flue-gas temperature prevailing in the region of a stage as a secondary correction quantity and influence the desired value depending on load in such a manner that while adhering to the limiting value of the SOx emission as a desired value of the primary correction quantity, the amount of additive is regulated via the degree of desulphurization of the additive which is dependent on temperature.
9. A method as claimed in Claims 1 to 8, characterised in that a component amount of the solid separated out of the flue gas originating from the actual combustion process is returned to the radiation chamber with or without the addition of unused additives, the introduction being effected in a region having a flue-gas temperature below the decomposition temperature of the reaction products from additives and harmful gases.
10. A method of reducing the gaseous harmful substances, such as SOx, fluorine or chlorine compounds for example, resulting during the combustion of fuels with a high calorific value, by introducing additives, by means of a carrier fluid, into the radiation chamber, following on the combustion chamber, of a steam generating plant, substantially as hereinbefore described with reference to the accompanying drawing.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19833340892 DE3340892A1 (en) | 1983-11-11 | 1983-11-11 | MULTI-STAGE METHOD FOR THE INTEGRATION OF GAS-SHAPED SUBSTANCES CONTAINED IN SMOKE GASES |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB8428014D0 GB8428014D0 (en) | 1984-12-12 |
| GB2152915A true GB2152915A (en) | 1985-08-14 |
| GB2152915B GB2152915B (en) | 1987-09-09 |
Family
ID=6214124
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08428014A Expired GB2152915B (en) | 1983-11-11 | 1984-11-06 | Multi-stage method of binding gaseous harmful substances contained in flue gases |
Country Status (2)
| Country | Link |
|---|---|
| DE (1) | DE3340892A1 (en) |
| GB (1) | GB2152915B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2579111A1 (en) * | 1985-03-25 | 1986-09-26 | Mediterranee Const Navales Ind | PROCESS FOR PURIFYING SMOKE FROM HOUSEHOLD INCINERATION PLANTS |
| US4681045A (en) * | 1986-07-21 | 1987-07-21 | William F. Cosulich Associates, P.C. | Treatment of flue gas containing noxious gases |
| DE3741842C2 (en) * | 1987-12-10 | 1995-04-20 | Steinmueller Gmbh L & C | Process for reducing the gaseous pollutants SO¶x¶, HF and HCl that arise during combustion |
| DE3805037A1 (en) * | 1988-02-18 | 1989-08-24 | Kloeckner Humboldt Deutz Ag | METHOD AND SYSTEM FOR THE DRY CLEANING OF EXHAUST GASES CONTAINING POLLUTANTS |
| SE501418C2 (en) * | 1992-05-18 | 1995-02-13 | Gothia Tool Trading Hb | Process and device at combustion unit to create conditions for reduction of environmentally harmful substances |
| DE10356590B3 (en) * | 2003-12-04 | 2005-02-17 | Lurgi Energie Und Entsorgung Gmbh | Non-stoichiometric process clean gas from e.g. refuse incinerator by regulated admixture of sorbent agent |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1510275A (en) * | 1975-09-22 | 1978-05-10 | Pullman Inc | Removal of sulphur oxides from waste gas |
| GB2011872A (en) * | 1977-09-06 | 1979-07-18 | Andersen H C M | Neutralization of acidic combustion gases |
| EP0008770A1 (en) * | 1978-09-12 | 1980-03-19 | Apparatebau Rothemühle Brandt & Kritzler Gesellschaft mit beschränkter Haftung | Installation for the separation of gaseous pollutants from flue gases |
| EP0034563A1 (en) * | 1980-02-15 | 1981-08-26 | Horst Dr. Ing. Gatzke | Method and device for the recovering of heat and for the cleaning of flue gases |
| WO1982002151A1 (en) * | 1980-12-23 | 1982-07-08 | Andersson Finn | A process of cleaning flue gases from heating plants,and a cleaning plant for carrying out the process |
| GB2135662A (en) * | 1983-02-26 | 1984-09-05 | Steinmueller Gmbh L & C | Method of binding sulphur compounds which are formed as reaction products during the combustion of fuels containing sulphur in a furnace |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2615828A1 (en) * | 1976-04-10 | 1977-10-13 | Heinz Hoelter | Gas purificn. by addn. of absorbent - in series of stages with sepn. and recycling of absorbent after each stage |
| DE2539500B2 (en) * | 1975-09-05 | 1980-06-19 | Heinz Ing.(Grad.) 4390 Gladbeck Hoelter | Process for separating dust and gaseous pollutants from hot exhaust gases and device for carrying out the process |
| JPS5394258A (en) * | 1977-01-31 | 1978-08-18 | Kurabo Ind Ltd | Control method and apparatus for nitrogen oxides removing apparatus |
| DE2739509C2 (en) * | 1977-09-02 | 1982-09-16 | Babcock-BSH AG vormals Büttner-Schilde-Haas AG, 4150 Krefeld | Method and device for cleaning an exhaust gas stream |
-
1983
- 1983-11-11 DE DE19833340892 patent/DE3340892A1/en active Granted
-
1984
- 1984-11-06 GB GB08428014A patent/GB2152915B/en not_active Expired
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1510275A (en) * | 1975-09-22 | 1978-05-10 | Pullman Inc | Removal of sulphur oxides from waste gas |
| GB2011872A (en) * | 1977-09-06 | 1979-07-18 | Andersen H C M | Neutralization of acidic combustion gases |
| EP0008770A1 (en) * | 1978-09-12 | 1980-03-19 | Apparatebau Rothemühle Brandt & Kritzler Gesellschaft mit beschränkter Haftung | Installation for the separation of gaseous pollutants from flue gases |
| EP0034563A1 (en) * | 1980-02-15 | 1981-08-26 | Horst Dr. Ing. Gatzke | Method and device for the recovering of heat and for the cleaning of flue gases |
| WO1982002151A1 (en) * | 1980-12-23 | 1982-07-08 | Andersson Finn | A process of cleaning flue gases from heating plants,and a cleaning plant for carrying out the process |
| GB2135662A (en) * | 1983-02-26 | 1984-09-05 | Steinmueller Gmbh L & C | Method of binding sulphur compounds which are formed as reaction products during the combustion of fuels containing sulphur in a furnace |
Also Published As
| Publication number | Publication date |
|---|---|
| DE3340892C2 (en) | 1989-06-15 |
| DE3340892A1 (en) | 1985-05-23 |
| GB2152915B (en) | 1987-09-09 |
| GB8428014D0 (en) | 1984-12-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |