The catalyst loading of the reactor purification of exhaust gases from nitrogen oxides and method of cleaning exhaust gases
(57) Abstract:Usage: when the catalytic neutralization of exhaust gases of various industries. The catalyst for purification of exhaust gases from nitrogen oxides by reduction of their flammable gases on the basis of the oxides of chromium, iron, copper, zinc, Nickel and aluminum, consists of a mechanical mixture of industrial contacts STC and NTC 10 1, taken in the ratio (0,5 5,0) 1. On this catalyst in one stage is achieved almost 100% conversion of oxides at 200 and 400°C. in the presence of large quantities of oxygen (up to about 20. ). The ratio of the number of supplied gas reductant to the oxygen content in the exhaust gases is within 0,06 0,80. 2 S. p. f-crystals. The invention relates to catalysts and methods of gas purification from nitrogen oxides by catalytic recovery flammable eyes and can be widely used in catalytic neutralization of exhaust gases of various industries.It is known that combustible gases (H2oil and natural gases, vapours kerosene, individual hydrocarbons) refer to "non-selective" reducing nitrogen oxides and primarily interact with the audience in acroreader the bulk of oxygen, in the reaction with the reducing agent into the oxides of nitrogen. Gas-reducing agent must be made in excess of the stoichiometric required by 10 to 20% i.e. the process carried out in a reducing environment (n CH4/O2of 0.5). The method of reduction of nitrogen oxides flammable gases spread only through high-performance low-cost catalysts containing noble metals 
Of scientific and technical literature there is a method of reduction of nitrogen oxides with methane, in which instead of the palladium catalyst used cheap iron oxide-copper catalyst deposited on the active - Al2O3 this catalyst achieved a 90% degree of the reduction of NO by methane bulk gas velocity of 10,000 h-1, temperatures of 600 800aboutAnd the ratio of CH4/O20,55 0,65. However, this cleaning method does not provide full recovery of oxides of nitrogen.Closest to the invention for technological entity and obtained the result is a method for reduction of nitrogen oxides with methane using a two layer catalyst  the First layer is a palladium catalyst APK-2 on the media and oxygen, present in the treated gas. In the second layer of the catalyst is the reduction of nitrogen oxides. The maximum conversion of NOx(100%) is achieved at the 25 th of oxide copper and copper-chrome (1 3,8) catalysts deposited on Al2O3.The disadvantages of the described method are: high process temperature (700 730aboutC) carrying out the process in two stages, the first layer of the catalyst containing 2% Pd, and the impossibility of its application for the treatment of gases with an oxygen content above about 3.The aim of the invention is to provide a method, which would allow for the cleaning process of oxygen-containing gases from nitrogen oxides restore their flammable gases in a single phase on the cheapest available catalyst at low temperatures with high efficiency.To achieve this goal the gas to be cleaned together with the reducing agent is passed through the catalyst bed at elevated temperature. In the cleaning process is applied multicomponent oxide catalyst comprising a mechanical mixture of industrial catalysts QCD and NTC-10-1, taken in the ratio (0,5 5,0) 1, respectively.Rolled the 88 wt. Fe2O3and 7 wt. Cr2O3. The catalyst NTC-10-1 (TU 113-01-31-44-87) was used in the production of butyl alcohol, it includes: CuO ( 40 wt.), ZnO ( 30 wt), NiO ( 5 wt.) and Al2O3( 17 wt.).According to the proposed method on the specified catalyst in one-step cleansing process can achieve almost 100% conversion of nitrogen oxides contained in the treated gas in the amount of 0.04 to 0.14. in the presence of significant amounts of oxygen (up to about 20.) both oxidising and reducing conditions in the temperature range 200 400aboutC. Optimal ratio of CH4/O20,06 0,60.In the scientific and patent literature, there are no messages on catalyst for purification of exhaust gases from nitrogen oxides and method of its use with the specified set of essential features. In this regard, the claimed solution meets the criterion of "novelty."The proposed catalyst is different from the catalyst of the prototype, first, the quantitative content of oxides of chromium, copper and aluminum, and secondly, the additional presence of oxides of iron, zinc, Nickel in such quantities that the ratio of catalysts NTC-10-1 and STK was 1 (0.5 of the political activity in the temperature range of 200 to 400aboutC. Method of use of the catalyst differs from the prototype the process of purification from nitrogen oxides restore their flammable gases in a single phase in the presence of up to about 20. oxygen in the ratio of CH4/O20,06 0,80.Analysis of scientific-technical and patent literature showed that there are no known laws and recommendations, according to which it would have been obvious to assume that a mechanical mixture of industrial catalysts STC and NTC-10-1, taken in the ratio (0,5 5,0) 1, respectively, must exhibit a high catalytic activity in the process of gas purification from nitrogen oxides at low temperatures, as well as the possibility of using this catalyst in a one-step process as in the reducing and oxidizing conditions. In accordance with this proposed solution meets the criterion of "prior art".P R I m e R 1. Used catalyst with the ratio of components STC STC-10 to 1 1.5 to 1. The composition of the gas at the inlet to the catalytic reactor, about. O219,9; N278,62; CH41,4; NOx0,08. The volumetric rate of gas flow 10 thousand h-1temperature 210aboutWITH A, CH4/O20,07. Conversion of NOx100%
P R and m the reactor, about. O29,4; N284,62; CH45,8; NOx0,18. The volumetric rate of gas flow 10 thousand h-1temperature 400aboutWITH A, CH4/O20,6. Conversion of NOx99,5% 1. The catalyst loading of the reactor purification of exhaust gases from nitrogen oxides, including oxides of chromium, copper, aluminium, characterized in that it is a mechanical mixture of industrial oxide catalysts: zhelezohromovyh brand JCC and copper-zinc-Nickel-aluminum brand NTC-10-1, taken in a volume ratio of 0.5 to 5.0 10 respectively.2. The method of purification of waste gases from nitrogen oxides by mixing the exhaust gases with gas-reducing agent, which is used as combustible gases, followed by passing the mixture of gases through the reactor with the catalyst loading at elevated temperature, characterized in that the ratio of the gas content of the reducing agent to the oxygen content in the exhaust gas when mixing is 0.06 to 0.80, as a catalyst using a mechanical mixture of industrial oxide catalysts: zhelezohromovyh brand JCC and copper-zinc-Nickel-aluminum brand NTC-10-1, taken in a volume ratio 0,5 5,0 1,0, as the gas mixture temperature support in d
FIELD: physical or chemical processes and apparatus.
SUBSTANCE: method comprises flowing air through the chemical absorber of nitrogen acids that is composed of chemically absorbing base that absorbs nitrogen dioxide and sorbent-oxidizer that oxidizes nitrogen mono-acid up to nitrogen dioxide. The chemical absorber is made of n pairs of layers of chemically absorbing base and sorbent-oxidizer. Upon flowing throughout n pairs of the layers, the initial concentration of the nitrogen dioxide drops by a factor of 3n, where n is the total number of pairs of the layers.
EFFECT: reduced cost and enhanced efficiency.
2 cl, 1 tbl
FIELD: methods of purification of flue gases.
SUBSTANCE: the invention is pertaining to the method of purification of flue gases and may be used to decrease the outbursts of nitrogen oxide with the help of the method of the high-temperature selective non-catalytic reduction. The method provides for feeding of the previously prepared steam-gaseous reduction mixture into the gas flue of the flue gas burning aggregate with the temperature of the flow of the purification gases of 700-1200°C. At that the steam-gaseous reduction admixture is prepared in the connected to the gas flue high-speed reactor during 0.5-5 seconds by introduction of a water solution of carbamide with a superheated steam at the pressure of 3-10 atm. Concentration of the water solution of carbamide makes 20-40 mass %. The time of the contact of the water solution of carbamide with the superheated steam predominantly makes 0,5-2 seconds. The pressure in the reactor predominantly makes 3-6 atm. The temperature of the superheated steam makes 200-400°C. The invention ensures simplification of the production process of purification of the effluent gases from nitrogen oxides, to increase the level of purification of such a gas in the broad range of the temperatures of the purified combustion products, and also to decrease significantly the share of the secondary contaminant - ammonia, in the purified gases.
EFFECT: the invention ensures simplification of the production process of the effluent gases purification from nitrogen oxides, to increase the level of purification of the gases in the broad range of the temperatures of the purified combustion products, to decrease significantly the share of the secondary contaminant - ammonia in the purified gases.
5 cl, 2 ex, 1 dwg, 2 tbl
FIELD: chemical industry; methods of neutralization and a utilization of the aggressive chemical compounds.
SUBSTANCE: the invention is pertaining to the field of neutralization and a utilization of the aggressive chemical compounds, in particular, the saturated with the anhydrides acid-containing compounds and wastes. The neutralization is applied to the smoke mixture containing the sulfuric anhydride and chlorosulfonic acid, or the oxidizing agent of the rocket propellant based on of the nitric acid containing a dimer of the nitrogen dioxide. For neutralization use the hydrolyzed dispersible aluminosilicates based of the natural clays selected from: hydromicaceous Cambrian clay, montmorillonite clay, kaolinite clay or on the basis of their mixtures. At that the hydrolyzed dispersible aluminosilicates, which are taken at least in equal shares with an aggressive chemical compound, are prepared at the following ratio of components (in mass shares): a dry substance - 1.0-2.5, water - 1.0. The invention allows to neutralize the aggressive wastes and to produce the useful product with the sorption activity.
EFFECT: the invention ensures neutralization of the aggressive wastes and production of the useful product with the sorption activity.
3 cl, 2 ex, 6 tbl
FIELD: gas purification.
SUBSTANCE: method comprises treating the flow of chimney gas in the high-temperature zone with a temperature of 700-1200°C by means of gas reducing mixture that is preliminary is produced by thermal decomposition of solid carbamide out of the zone for treating the gas and is supplied to the zone of purification by the gas-carrier. The carbamide is decomposed by rising its temperature from 100 to 600°C. The rate of the temperature rise is 5-40°C/min and 35-40°C/min for the temperature range from 100 to 400°C and temperature higher than 400°C, respectively.
EFFECT: simplified method.
3 cl, 1 dwg, 1 tbl
FIELD: non-catalytic method of reduction of nitrogen oxide emission in combustion product flow.
SUBSTANCE: proposed method includes bringing in contact effective amount of at least one nitrile compound fed to combustion apparatus in form of separate liquid flow or in form of separate gas flow with flow of wastes fed to combustion apparatus in non-separated form, additional fuel flow and air at temperature sufficient for reduction of NOx emission in flow of combustion products.
EFFECT: reduction of nitrogen oxide emission in combustion product flow.
13 cl, 4 tbl, 3 ex
FIELD: cleaning waste flue gases of tubular furnaces used in power technological plants of ammonia production process from nitrogen oxides.
SUBSTANCE: proposed method includes mixing flue gases with air and ammonia-containing reductant. Used as ammonia-containing reductant are synthetic gases of ammonia production process of the following composition, mass-%: ammonia, 20-30; methane, 18-24; hydrogen, 25-35; argon, 3.8-4.8; the remainder being nitrogen. Selective catalytic reduction of nitrogen oxides of flue gases is performed in reactor at temperature of 240-450°C with the use of tungsten-vanadium catalyst. Proposed method makes it possible to clean flue gases to 91%.
EFFECT: high degree of cleaning.
FIELD: cleaning exhaust gases from nitrogen oxides in industrial plants by means of selective catalytic cleaning with the use of ammonia.
SUBSTANCE: proposed method includes reduction of nitrogen oxides by ammonia on catalyst in presence of hydrogen. Before delivery to catalyst, exhaust gases are mixed with purge gases from the ammonia synthesis cycle. Content of hydrogen in mixture is maintained below low limit of ignition. Purge gases are enriched with ammonia by mixing them with ammonia synthesis gases.
EFFECT: reduced consumption of ammonia; enhanced mixing of exhaust gases with ammonia; reduced emissions of ammonia into atmosphere; reduced power requirements.
FIELD: inorganic synthesis catalysts.
SUBSTANCE: decomposition if N2O under Ostwald process conditions at 750-1000°C and pressure 0.9-15 bar is conducted on catalyst, which comprises (A) support composed of α-Al2O3, ZrO2, SeO2, or mixture thereof and (B) supported coating composed of rhodium or rhodium oxide, or mixed Pd-Rh catalyst. Apparatus wherein N2O is decomposed under Ostwald process conditions on the above-defined catalyst is also described. Catalyst is disposed successively downstream of catalyst grids in direction of stream of NH3 to be oxidized.
EFFECT: increased catalyst activity.
8 cl, 2 tbl, 3 ex
FIELD: chemical industry; other industries; methods of the selective non-catalytic purification of the flue gases from nitrogen oxides.
SUBSTANCE: the invention is pertaining to the processes of the selective non-catalytic purification of the flue gases from nitrogen oxides and may be used for reduction of the contents of the nitrogen oxides in the low-temperature flue gases from the fuel-burning installations. The method of the selective non-catalytic purification of the flue gases from nitrogen oxides provides for feeding in the flow of the end flue gases having the temperature 200-700°С of the gaseous reduction mixture previously produced by the joint thermal decomposing of carbamide and hydrogen peroxide at the temperature of 150-500°С. For production of the gaseous reduction mixture they use either the water solutions of carbamide peroxihydrate or carbamide and hydrogen pyroxide, either carbamide peroxihydrate in the solid kind. The reduction gas mixture is fed by means of the carrier gas, in the capacity of which use the water steam, the flue gases, the compressed air, nitrogen. The concentration of the water solutions of carbamide and hydrogen peroxide makes 1-40 mass % and 0.5-20 mass %. The technical result of the invention is the increase of efficiency of purification of the flue gases from nitrogen at the low temperatures without formation of the secondary contaminants.
EFFECT: the invention ensures the increased efficiency of purification of the flue gases from nitrogen at the low temperatures without formation of the secondary contaminants.
4 cl, 3 tbl, 2 ex