TH20143A - Methods for gas purification containing nitrogen oxide and equipment for gas purification in steam generators - Google Patents

Abstract

A method of reducing the nitrogen oxide level in the fuel gas emitted by the unit. Burned by introducing redundant gas with nitrogen oxide in the first reduction step. And the second will be arranged The first reduction step is a non-catalytic step (ie at temperatures above 800 ํ C) while the first reduction step is a catalytic step (ie, at temperatures around 300-400 ํ C .) The steam generating boiler with the improved nitrogen reduction facility is Arranged as well The amount of nitrogen oxide in the hot gas is reduced in the combustion of the phase. First and second reduction While steam generating in a boiler system, the steam generation has a significant effect on gases that are free from nitrogen oxides. While eliminating the possibility of NH3 (or other reducers) emanating in the exhausted fuel gas. Heat transfer in The recirculation part, as it was used, was used to create a constant temperature condition for the accelerated reduction.

Claims (3)

1. Method of gasification from combustion from a pure steam generation plant This plant consists of a fuel reaction chamber. And rotation part Circulating the fuel gas, which is operable, is connected to the reaction chamber, the circulation section provides the heat transfer section for the extraction of heat from the gas. Burning in the reaction chamber resulting in (B) hot gas with nitrogen oxide is produced. (B) The supply of this hot gas from the reaction chamber and conduction of the hot gas. In the recirculation section (c) the cooling of the gas in the fuel gas circulation (d) the reduction of nitrogen oxides in the first reduction step by hot gas conduction. And therefore (e) reduction of nitrogen oxides in the second reduction stage by forcing the gas With the reducer of the first reduction step to the accelerated NOx reduction In the fuel gas recirculation, while maintaining the gas temperature in The second reduction step inside the compartment is approximately + - 25 ํ C of working temperature. 2. The method according to claim 1, in which the material saver with the surface Heat transfer is provided in the recirculation section. And where a phase (e) is performed after the gas has passed through the heat transfer surface of the material saver and the phase (d) before that gas is passed through the heat transfer surface. of Raw material saver 3. Method according to claim 1, in which the raw material saver has a surface Heat transfer is provided in the recirculation section. And where the procedure (e) is followed Before that gas is passed through the heat transfer surface of the material saver 4. Method according to claim 1, in which procedure (c) is performed in order to perform Cool the gas in the recirculation section at <500 ํ with the heating surface. The steam of the recirculation part is heated before the catalytic reduction in the second reduction step. 5. Method according to claim 1, in which step (c) is followed in order to do so. The gas is cooled in the recirculation section at approximately 300-400 ํ before the second reduction step and step (d) is performed before step (c). 6. Method of claim clause. 1. By the next step of keeping the temperature. Of gas in the second reduction stage at a level within + - 25 ํ of the maximum operating temperature. The catalyst was used in the second reduction stage by controlling the flow rate of the The heat transfer medium in the recirculation section before the second reduction step 7. Method according to claim 6, in which step (d) is performed by injection. The reducer enters into contact with the hot gas at one or more positions corresponding to the support. Burden of steam generation of steam generating plants 8. Method of claim 5 where procedure (d) is to be performed by conducting The hot gas comes into contact with the reducer at temperature> 800 ํ in order to have the effect of reducing NOx in hot gas without catalyst. 9. Method according to claim 1, where the procedure ( e) will be treated in order to Reduce any excess amount of redundant in the hot gas before that gas leaves the recirculation section 1 0. The method of claim 1, where a procedure (e) is to be performed in order to Pass that hot gas through the catalytic bake over the valuable linear flow distance Less than about 2 m. 1 1. Method according to claim 1, in which the procedure (a) - (e) will be treated until Until the process accelerated operating pressure loss (e) is less than 50% of the pressure loss for conventional catalyzed reduction 1 2. Method according to claim 1. Where the pressure loss of practice The catalyst at step (e) is less than approximately 400 l \ 'a 1 3. The method in claim 1, where the reducer is introduced into the step (d), will Is selected from the group that contains Substances containing amines, ammonia, urea, or ammonia. Pre-produced 1 4. Method of pure gas combustion. From fluidized bed factory Steam generation The steam generation plant consists of a fluidized bed reaction chamber. Particle separator connected to the reaction chamber And the fuel gas circulation Which is connected to the particle separator and there is a heat transfer element for heat extraction For extracting heat from gas The method consists of steps of (a) treatment of combustion reaction in fluidized bed solids in the chamber. The fluidized bed reaction results in the production of hot fuel gas (b), the supply of hot gas and particles brought simultaneously from the reaction chamber. And the introduction of this gas and particle into the particle separator (c) separation of the gas particles in the separator (d) in the first reduction step. The hot gas is brought into contact with the reducer, which results in a reduction in the NOx content of this gas under conditions without accelerators. The reaction is then (e) the cooling of the gas in the fuel gas recirculation and (f) in the second reduction step. Forcing gas with a reductor of the procedure Reducing first to reduction of NOx accelerated in the gas circulation. Fire after performing step (e) while maintaining gas temperature. In the second reduction step Within the maximum operating temperature of the accelerator 1 5. Method according to Clause 14 in which this plant will include economizers. Objects with a heat transfer surface in the recirculation section And where a step (f) is performed after the gas has passed through the heat transfer surface of the machine. Raw material saving 1 6. Method according to Clause 14, where this plant will include economical machines. Raw materials with a charcoal heating surface in the recirculation section And where the procedure (f) is performed before the gas passes through the heating surface of the economizer 1 7. Method according to claim 14, where step (e) Will be treated in order to Cool the gas in the recirculation section at <500 ํ C with the dosing surface. The steam heating of the recirculation part before the catalytic reduction in step (f) 1 8. Method according to claim 17, where step (e) is to be performed to perform The gas is cooled in the recirculation section from temperature> 800 ° 0C to a temperature of approximately 300-400 ° C before the catalyst reduction in step (f) 1. 9. Method of claim. Article 14 also includes the process of treatment. The gas temperature in the second reduction stage is within + - 25 ํ C of the heating temperature. The maximum work of the catalyst is used in the second reduction stage by controlling the flow rate. Of the heat transfer medium in the recirculation section before the second step 2 0. Method according to claim 14, where step (d) is performed by Hot gas is brought into contact with the reducer at temperature> 800 ํ C to have an effect on NOx acid in hot gas without catalyst 2. 1. Procedure in Clause 19 where Procedure (d) will be followed by Inject the reducer into contact with the hot gas at one or more positions corresponding to the secondary. Loaded of steam generation of steam generator 2 2. Procedure according to Clause 14, where Procedure (f) will be followed in order to: Through that hot gas through the catalytic bake or a valuable linear flow distance Less than about 2 m 2 3.The method specified in Clause 14, where procedure (d) will be performed at In order to reduce the NOx content of that gas to approximately 60 ppm or less, and where a procedure (f) is performed at a temperature of approximately 300-400 ํ. In order to reduce the amount of NOx of that gas to about 20 ppm or less and until the possibility of emission of NH3 or substantially dispersed reducer is eliminated.