Denitration method and device of catalytic cracking regenerated flue gas

Abstract

The invention discloses a denitration method and device. The denitration method utilizes a carbon material to purify petroleum catalytic cracking regenerated flue gas. A carbon-containing substance, which has been infiltrate in manganate, is taken as the denitration agent. The denitration agent can be used to reduce oxynitride and can also be used as a catalyst in the reduction reactions between carbon monoxide and oxynitride. The reactor group is composed of at least two parallelly-connected reactors, the side surfaces of the reactors are provided with a flue gas inlet, and a carbon feed inlet and an ash discharge outlet are respectively arranged in the top part and bottom part of a reactor. The catalytic cracking regenerated flue gas has the characteristics of high temperature, low oxygen content, and high carbon monoxide concentration, the provided denitration method and device fully utilize the characteristics mentioned above, is capable of processing a large amount of flue gas, has the advantages of good denitration effect, low operation cost, and no secondary pollution, and is not affected by the impurities in flue gas. The invention belongs to the field of environment protection.

Description

technical field [0001] The invention relates to a new method and device for denitrification of catalytic cracking regenerated flue gas, which belongs to the field of environmental protection. Background technique [0002] Catalytic cracking is an important petroleum processing process. The catalytic cracking catalyst circulates between the reactor and the regenerator. When the catalyst leaves the reactor, 3%~10% of coke usually adheres to it, which must be oxidized and burned in the regenerator to restore the catalyst. active. The coke deposited on the catalyst often contains sulfur and nitrogen, and the coking process will release a complex exhaust gas, usually containing 1%~10%CO, 300~6000mg / Nm3SOx, 50~500mg / Nm3NOx, 150~300mg / Nm3 dust, O2 is usually less than 1%, and may also contain a small amount of volatile organic compounds such as tar. The temperature of the regenerated flue gas is usually 600°C~700°C, and the heat energy of the flue gas usually passes through the ...

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Problems solved by technology

Another disadvantage of SCR is the use of a structured catalyst carrier, which is very sensitive to particulate matter and tar in the flue gas

Another commonly used method is selective non-catalytic reduction, referred to as SNCR. This method also uses ammonia or urea as a reducing agent, and sprays ammonia or urea solution into the temperature range of 850~950°C on the upper part of the boiler furnace to reduce nitrogen oxides. for N 2 , the investment of this method is not large, but the denitrification efficiency is very low, usually between 50% and 60%. The biggest problem of this method is that the effective temperature window of the reaction is very narrow, usually at 50~100°C, when the temperature is lower than 850°C , the denitrification efficiency is very low. After the temperature is higher than 950°C, the injected ammonia or urea will be oxidized to form nitrogen oxides

SNCR denitrification is obviously not suitable for catalytic cracking regeneration flue gas denitrification

Another type of wet denitrification method that pays more attention to oxidation followed by reduction has a good denitrification effect, but the consumption of oxidants such as ozone, sodium hypochlorite, and potassium permanganate is very high, and most of them cannot bear

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