Method for hydrolysis-oxidation coupled purification of HCN

Abstract

The invention discloses a method for hydrolysis-oxidation coupled purification of HCN, belonging to the field of gaseous pollutant control. According to the method, a catalyst takes Fe, Mn, Mo and W as active ingredients for hydrolysis and oxidation, and a Co(II)Schiff base complex, cobalt phthalocyanine sulfonate and the like, which serve as oxygen storing active ingredients, and rare-earth-metal active substances, such as La, Ce and the like, are added to improve the hydrothermal stability of the catalyst, so that HCN can be subjected to hydrolysis-oxidation coupled catalytic purification under low-temperature and micro-oxygen conditions and is finally converted into non-toxic and harmless products, namely N2, CO2 and water, and the selectivity of N2 is high. A preparation method of the catalyst is simple in process and low in cost.

Description

technical field [0001] The invention relates to a hydrolysis-oxidation coupling purification method for HCN, which realizes the harmless conversion of HCN and belongs to the field of air pollutant control. Background technique [0002] HCN is a toxic and highly corrosive gas that inhibits the function of respiratory enzymes in humans and other warm-blooded animals so that tissues cannot normally obtain oxygen from the blood and suffocate. Coal, biomass and other substances are pyrolyzed or burned at high temperatures During the process, the contained nitrogen element will be partially converted into HCN, such as high-temperature coal pyrolysis gas, blast furnace gas, converter gas and coke oven gas, biomass pyrolysis gas, ore-heating electric furnace tail gas And the coal chemical industry contains a large amount of HCN. Due to the strong toxicity of HCN, HCN waste gas purification must meet strict environmental emission and hygiene standards to prevent HCN from causing air ...

AI Technical Summary

Problems solved by technology

[0004] Patent CN 102921285 A discloses a circulating liquid sprayed with oxidant hydrogen peroxide, catalyst and acidity regulator to absorb HCN, and convert HCN into N2, CO2, this method has the problem of disposal of invalid circulating fluid, patent CN 101108337 A discloses a catalyst for the decomposition of HCN, which is composed of aluminum oxide, silicon oxide, Titanic acid, squash powder, inorganic salts, nitric acid, etc. are prepared as catalysts to convert HCN into NH3, and other COS, CO2, etc. In this method, HCN is decomposed, but the generated by-products still have a certain degree of pollution; patents CN 1404905 A, CN1404900 A, and CN 1404904 A use catalysts such as platinum, rhodium, and palladium to oxidize and purify HCN. In this method, the reaction temperature is 250-550 °C , the temperature is relatively high, and the price of precious metals is expensive; patent CN 142652 A discloses a catalyst preparation method for supporting Cu, using the catalyst to catalyze the combustion of HCN. sub>3, tar and air mixture are fed into the furnace, and the exhaust gas is removed by catalytic combustion. The patented method can control the production of NOx, but the reaction temperature is still high , In addition, the oxygen content in the reaction conditions is relatively high, and under the working conditions where the oxygen content is strictly limited, the purification effect on HCN is limited

[0005]General HCN purification methods often require higher oxygen content, but yellow phosphorus tail gas, closed calcium carbide furnace tail gas, graphite production tail gas, water gas, biomass The main components of several gases such as pyrolysis gas are CO, H2, CH4 or their mixed gas, because CO, H2 , CH4 or their mixtures are explosive. When the oxygen content exceeds a certain amount, there is a huge safety hazard. The oxygen content in these types of gases is very low, less than 0.5%. Therefore, the development of purification The low-temperature micro-oxygen catalyst of HCN is very necessary