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 [1]

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[2] 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 [3] 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

 

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5 cl, 2 ex, 1 dwg, 2 tbl

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3 cl, 2 ex, 6 tbl

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3 cl, 1 dwg, 1 tbl

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8 cl, 2 tbl, 3 ex

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