272results about How to "Improve denitrification performance" patented technology

The invention discloses a flue-gas denitration catalyst incapable of being deactivated by basic metallic oxides, a preparation method thereof and applications thereof. The catalyst comprises following components by weight: 70-85% of nanometer titanium dioxide, 1-3% of V2O5, 5-15% of heteropoly acid, 3-15% of glass fiber and 4-10% of an inorganic binder. In the preparation method, active components and the heteropoly acid are loaded step by step. The catalyst has high denitration performance and high performance of resistance to deactivation by the basic metallic oxides, and is particularly suitable for flue gas denitration of a power plant, an industrial boiler, an incinerator, a cement kiln, and the like, wherein the power plant, the industrial boiler, the incinerator, the cement kiln, and the like adopt biomass as fuel and contain a large amount of basic metallic oxides in flue gas.

The invention provides a catalytic agent for denitrating smoke and a preparation technology thereof. The catalytic agent for denitrating the smoke comprises the raw materials based on parts by weight as follows: 60%-90% of titanium dioxide, 3%-9% of tungsten trioxide, 0.5-3% of vanadium pentoxide, 2%-5% of organic binder, 10%-20% of inorganic binder, 7%-10% of glass fiber, 2%-4% of plasticizer, 20%-40% of water, 2%-4% of lubricant, 0.1%-1% of surface active agent and 3%-9% of neutralizer. After the content of the tungsten trioxide is reasonably proportioned, on the premise of guaranteeing thedenitration performance of the catalytic agent for denitrating the smoke, the absorption to sulfur dioxide is reduced, the SO2/SO3 conversion percentage is reduced, and the high-sulfur and high-ash use requirement of the coal quality in China is met.

The invention relates to a low temperature selective catalytic reduction (SCR) moving bed flue gas denitration method for a coal-fired boiler. Boiler flue gas subjected to dust removal and a denitration reducer NH3 are introduced into a denitration reactor respectively; a low temperature SCR catalyst is continuously input from one end of the denitration reactor and continuously output from the other end of the denitration reactor to form a moving bed; the flue gas and the NH3 are in gas-solid contact with the catalyst which moves directionally in a countercurrent or crosscurrent mode in the reactor; NOx and NH3 in the flue gas are reacted with each other and the generated N2 and water vapor are discharged out of the denitration reactor along with the denitrified flue gas; in the process, parts of SO2 and NH3 in the flue gas are reacted with each other and the generated sulfate is deposited on the catalyst; and an inactivated catalyst which is continuously output from the denitration reactor enters a regenerative process, the regenerated catalyst returns to the reactor and the steps are continuously and repeatedly circulated by the method. By continuously regenerating the catalyst, the method solves the problem of catalyst poisoning and improves the denitration efficiency and running stability of a system.

The invention discloses perovskite-type substance La<1-x>SrCrO<3>, a heat-engine plant denitration composite catalyst, and preparation methods of the perovskite-type substance La<1-x>SrCrO<3> and the heat-engine plant denitration composite catalyst, and belongs to the technical field of flue gas denitrification catalyst. The preparation method of the perovskite-type substance La<1-x>SrCrO<3> is used for solving a problem that existing preparation method of the perovskite-type substance is complex. According to the preparation method of the perovskite-type substance La<1-x>SrCrO<3>, lanthanum nitrate, strontium nitrate, and chromium nitrate are taken as raw material precursors, and are dissolved in water, and then are subjected to high-temperature roasting so as to obtain finished products. The preparation methods of the heat-engine plant denitration composite catalyst is used for solving a problem of existing denitration catalyst that ammonia is released in denitration processes. According to the preparation methods of the heat-engine plant denitration composite catalyst, a titanium dioxide mixture, an active liquid, water, glycerin, ethylene glycol, glass fiber, and aluminium dihydrogen phosphate are subjected to kneading so as to obtain ceramic clay; the ceramic clay is subjected to vacuum extrusion so as to obtain honeycomb ceramic blank; and the honeycomb ceramic blank is subjected to steam drying and roasting so as to obtain products. The heat-engine plant denitration composite catalyst is high in denitration rate, and is capable of solving a problem of ammonia escaping.

The invention discloses a heteropoly-acid-doped cerium oxide SCR denitration catalyst. The heteropoly-acid-doped cerium oxide SCR denitration catalyst is characterized in that heteropoly acid is Keggin-type phosphotungstic acid HPW, and the doped amount of the heteropoly acid is 5wt% to 15wt%. According to the catalyst, anatase TiO2 serves as a carrier, a mixture of cerium oxide CeO2 and the Keggin-type phosphotungstic acid HPW loaded to the carrier serves as an active component, and the catalyst is represented as CeO2-HPW/TiO2. The catalyst contains the following ingredients by content: 65wt% to 85wt% of TiO2 and glass fibers, 5wt% to 20wt% of CeO2 and 5wt% to 15wt% of HPW. The invention further discloses a preparation method for the catalyst and an application of the catalyst. The catalyst has relatively high catalytic oxidation-reduction power and acidic sites and achieves relatively high catalyst reaction activity at relatively low reaction temperatures, so that the low-temperature denitration efficiency and sulfur resistance are effectively improved.

The invention relates to a low-temperature selective catalytic reduction (SCR) fixed bed flue gas denitrification method and a low-temperature SCR fixed bed flue gas denitrification device for a coal-fired boiler. The method comprises the following steps of: introducing flue gas and ammonia gas serving as a denitrification reducing agent into one denitrification reactor, wherein the denitrification device is provided with more than two denitrification reactors; depositing sulfate generated by reacting SO2 in the flue gas with the ammonia gas on a catalyst to inactivate the catalyst; stopping the denitrification work of the denitrification reactor in which the catalyst is inactivated, starting another denitrification reactor for denitrification reaction, introducing regeneration gas into the denitrification reactor in which the catalyst is inactivated to regenerate the catalyst, replacing the denitrification reactor in which the catalyst is inactivated with the denitrification reactor in which the catalyst is regenerated, and recycling; and decomposing the SO2 and the ammonia gas in the regeneration process, and discharging the decomposed gas from the denitrification reactor. In order to overcome the difficulty of the conventional low-temperature SCR technology in practical application, the invention provides the low-temperature SCR device and the low-temperature SCR method for the coal-fired boiler, which are feasible and wide in application range.

The invention relates to a treatment method for removing nitrogen oxides by virtue of an ozone function. The method comprises the following steps: (1) flue gas containing the nitrogen oxides is introduced into a flue and an ozone adding distributor is additionally arranged; (2) a gas source is introduced into an ozone generator, ozone is generated and diluted and then is mixed in a mixer to obtain ozone diluted uniformly, and the ozone diluted uniformly enters the ozone adding distributor; (3) the ozone diluted uniformly and the flue gas containing the nitrogen oxides are mixed in the ozone adding distributor and are subjected to oxidation reaction, NO in waste gas is converted into high-valent nitrogen oxides and then the high-valent nitrogen oxides enter an absorption tower; and (4) the flue gas is absorbed by the absorption tower and absorption liquid and is purified to obtain tail gas, and the tail gas is exhausted from a chimney. The treatment method for removing the nitrogen oxides has the high efficiency, the low energy consumption and the convenience in use.

The invention belongs to the technical field of environmental protection and discloses an adsorbent for boiler fume treatment. The adsorbent is prepared from the following raw materials: manganese acetate, humic acid, ferric trichloride, silica-gel powder, zeolite powder, dolomite, bentonite, phenolic resin, peanut shell, wheat bran, a 2M sodium carbonate solution, turfy soil and water. The adsorbent disclosed by the invention has a relatively good adsorption effect on main harmful gases such as NOx, SO2 and dust in fume.

The invention discloses a desulfurization and denitration ammonia-removing system. The system comprises an adsorption tower, a desorption tower, a distributor, a first activated carbon conveyer and asecond activated carbon conveyer. One side of the adsorption tower is provided with a smoke inlet A, and the other side of the adsorption tower is provided with a smoke outlet B, the interior of the adsorption tower is provided with an adsorption cavity and an ammonia-removing cavity, the adsorption cavity is installed at one side adjacent to the smoke inlet A, the ammonia-removing cavity is installed at one side adjacent to the smoke outlet B, the first activated carbon conveyer is connected with a discharging port of the adsorption tower and a feeding port of the distributor, the second activated carbon conveyer is connected with a discharging port of the desorption tower and a feeding port of the adsorption cavity, a discharging port of the distributor is respectively connected with a feeding port of the ammonia-removing cavity and a feeding port of the desorption tower. The system adopts a mode that the adsorption tower is divided to two functional areas. The adsorption reaction cavity is capable of achieving the functions of desulfurization, denitration, dust removal and the like. The ammonia-removing cavity is filled with fresh activated carbon or acidic activated carbon, andis capable of gathering ammonia in smoke passing through an adsorption reaction layer, and effectively preventing the ammonia at the outlet from escaping.

The invention discloses an SNCR (selective non-catalytic reduction) denitration device and an SNCR denitration method for a rotary cement kiln and belongs to the technical field of rotary cement kiln pollutant discharge control. The device comprises a reducing agent preparation and storage system, a reducing agent transporting system, a reducing agent spraying system and a control system, wherein the reducing agent preparation and storage system consists of a reducing storage tank and a reducing agent dissolving tank, the reducing agent transporting system consists of a conveying pump and a conveying pipeline, the reducing agent spraying system consists of a booster pump and two stages of spray guns, and the control system consists of two flow meters and two flow meter controllers; and the device further comprises NOx on-line detection instruments respectively positioned in a position with the distance being 10 to 20m from the downstream parts of the two-stage spray guns. The method is realized by using the device, ammonia, urea or alkaline industrial waste liquid is used as a reducing agent, the proportion of the quantity of nitric oxide substances in smoke of a decomposing furnace and the quantity of nitrogen element substances in the reducing agent is determined according to the condition of NOx purified by each stage of spray gun, and the reducing agent is sprayed into the decomposing furnace. The SNCR denitration device and the SNCR denitration method have the advantages that economy and environment protection are realized, the operation is simple, the control is flexible, and the denitration performance is high.

The invention relates to a CO boiler having the dustproof function and the denitration function. The CO boiler having the dustproof function and the denitration function comprises a flue, a combustion chamber, steam drums, an evaporation section and an economizer section. The CO boiler further comprises an ammonia spraying and mixing mechanism and a dustproof denitration reactor. The ammonia spraying and mixing mechanism is arranged above the evaporation section or between the evaporation section and the denitration reactor. The dustproof denitration reactor is arranged between the evaporation section and the economizer section and comprises a mixed-smoke inlet section, a denitration section and a purified-smoke discharging section, wherein an ash removal section is arranged between the mixed-smoke inlet section and the denitration section, ash baffles are arranged in the ash removal section, an ash bin is arranged in the denitration section, the center line of the ash bin and the center line of the reactor coincide, and the lower end of the ash bin is connected with an ash discharging pipeline. According to the CO boiler having the dustproof function and the denitration function, the denitration reactor is arranged in the CO boiler, so that the utilization rate of smoke heat is increased; due to the fact that the ash removal section is arranged in the reactor, smoke dust of mixed smoke can be removed before the mixed smoke enters denitration units, catalyst hole channels are prevented from being blocked, and the denitration efficiency and the denitration effect are improved.

The invention discloses a fluent-based method for arranging a selective non-catalytic reduction (SNCR) spray gun on a circulating fluidized bed boiler. The method comprises the steps of 1, introducing a physical model of the circulating fluidized bed boiler into fluent; 2, setting the boundary conditions in the physical model, and carrying out numerical simulation to obtain the temperature and the velocity field of flue gas from a hearth to a separator; arranging the SNCR spray gun at the position where the temperature and the velocity field meet the first condition; 3, calculating the mixing effect of a reducing agent in a flue according to the position of the SNCR spray gun; 4, judging whether the mixing effect meets the second condition of the arrangement of the spray gun or not; if not, continuously adjusting until the position of the SNCR spray gun is determined; and 5, according to the determined position of the SNCR spray gun, arranging the SNCR spray gun at the position corresponding to the circulating fluidized bed boiler. The chemical reaction and the combustion reaction of the reducing agent in the flue are considered by the method, so that the denitration effect of the circulating fluidized bed boiler can be improved.

The invention relates to the field of ship flue gas denitrification equipment, in particular to a urea powerful mixing device for an SCR system of a small and medium-sized ship. The urea powerful mixing device for the SCR system of the small and medium-sized ship comprises a tube body, a porous plate, a urea nozzle and a mixing device, wherein the porous plate, the urea nozzle and the mixing device are arranged in the tube body from bottom to top; a flow rectifying device is the porous plate where a plurality of round holes are distributed, and a flow disturbing device is the mixing device; and the device has the beneficial effects that the flow rectifying device (porous plate) is arranged at the upstream position of the urea nozzle, the flow disturbing device is arranged at the downstream position of the urea nozzle, and due to the structure, smoke and sprayed urea mist can be more sufficiently mixed in the limited space, the urea nozzle can absorb more smoke gas waste heat in a short time so as to improve the decomposition speed, and therefore it can be ensured that the concentration ratio of NH3/NOX meets the reaction requirement when mixed smoke gas enters an SCR reactor inlet.

The invention discloses a ruthenium-based ultralow-temperature denitration catalyst, and belongs to the technical field of denitration catalysts. The denitration catalyst is prepared by sectional dipping and roasting and comprises the following components in percentage by mass: 1.22-2.84% of cerium element, 10.42-11.7% of manganese element, 1.14%-2.68% of ruthenium element and 45.84%-47.02% of titanium element. Compared with an existing Ce-Mn/TiO2 catalyst, the catalyst disclosed by the invention has the advantages that the denitration effect is good under an ultralow-temperature of 80-120 DEGC, anti-poisoning performance is remarkably improved, the service life is long, and the like.

The invention relates to environmental protection equipment and a denitration and dust-removing device, in particular to a gas-solid separator, as well as a denitration and dust-removing device. The gas-solid separator comprises a smoke gas distribution chamber. The smoke gas distribution chamber is provided with a smoke gas inlet for introducing a to-be-separated gas in a first direction; a plurality of gas cavities which are communicated mutually are distributed in the smoke gas distribution chamber in the first direction; and the volume of the plurality of the gas cavities is gradually reduced in the first direction. The smoke gas distribution chamber is connected with a plurality of cyclone separation assemblies which are in one-to-one correspondence with the plurality of gas cavities; each separation assembly comprises a cyclone cylinder and a gas discharge pipe which are matched mutually; the cyclone cylinder is provided with a gas inlet and flow guide end which is used for input gas and positioned in the gas cavities; and the gas discharge pipe partially stretches into the cyclone cylinder and penetrates through the smoke gas separation chamber. The denitration and dust-removing device comprises a shell and the gas-solid separator. The gas-solid separator, as well as the denitration and dust-removing device, protects a catalyst and prolongs the service life of the catalyst to finally realize the technical effects of improving the denitration effect and reducing the cost.

The invention discloses a preparation method and application of a catalyst containing a low-silicon composite metal Beta molecular sieve. The Fe-Beta molecular sieves with different morphologies are prepared by a one-step method by controlling the composition of synthesis raw materials and a structure-directing agent under the condition of no template agent, so that the acidity and pore channels of the molecular sieves are optimized, and the purpose of optimizing the performance of the molecular sieves is achieved. Lanthanum salt is used for further modifying the Fe-Beta molecular sieve for the first time by adopting an impregnation method, so that the denitration temperature interval of the Fe-Beta molecular sieve is greatly widened, the denitration performance and hydrothermal stabilityof the Fe-Beta molecular sieve are improved, and the Fe-Beta molecular sieve is relatively good in sulfur poisoning resistance and relatively low in cost. The low-silicon composite metal Beta molecular sieve catalyst disclosed by the invention is mainly used for treating NOx-containing tail gas and flue gas, and has excellent NOx selective reduction capability, good hydrothermal stability and HC carbon deposition resistance and sulfur poisoning resistance in a low-temperature range.

The invention relates to a hydrogen peroxide denitration process and a corresponding denitration system. According to the denitration process, hydrogen peroxide is taken as an oxidant; .OH is generated through high-temperature and high-pressure catalysis of hydrogen peroxide; .OH is mixed with flue gas, so that nitrogen oxides in the flue gas can be oxidized and recovered; finally, the obtained mixture is subjected to gas-liquid separation, denitration by-products, namely nitric acid and a nitrous acid liquid, are recovered, and the flue gas subjected to denitration is discharged to the outside. The denitration process and the denitration system have the advantages that hydrogen peroxide is taken as the denitration oxidant; through the mixing of hydrogen peroxide and high-temperature steam, hydrogen peroxide tends to be decomposed into hydroxy radical.OH and HO2., so that the nitrogen oxides oxidation and recovery effects are improved, the denitration rate is increased, and the temperature limitation is avoided.

The invention discloses a green and efficient incineration method for hazardous waste in a rotary kiln based on oxygen enriched air supply in a secondary combustion chamber. The method comprises the steps of (1) adding solid waste, liquid waste and a first combustion-supporting gas to the rotary kiln for performing treatment; (2) feeding the waste and the liquid waste which are treated by means ofthe rotary kiln and a second combustion-supporting gas into a secondary combustion chamber for performing combusting treatment; and (3) exhausting the gas which is obtained after the combustion in the secondary combustion chamber, wherein the second combustion-supporting gas is formed by mixing air and an oxygen enriched gas; the incineration temperature in the secondary combustion chamber is risen to 1,100 to 1,200 DEG C; the oxygen concentration of the second combustion-supporting gas is 23 to 28 percent; the oxygen content of a combustion environment in the secondary combustion chamber isimproved, and a technical means of the preheating is effectively utilized, which are beneficial to removing nitrogen oxides from flue gas in a waste heat utilization system under the condition of ensuring complete decomposition of the harmful substances, such as dioxin; the production and emission of secondary environment pollution substances in an incineration processing process are avoided or remarkably reduced; and efficient and green treatment of maximum reduction of the hazardous waste is realized.