Catalytic absorbent prodn. from mixed inorganic and organic waste - contg. catalytic heavy metal and carbon by pyrolysis and activation, used in waste gas purificn.

摘要

Prodn. of absorbent (I) with catalytic properties and a BET surface area of over 100 m2/g is carried out by pyrolysis of a moulded and dried mixed prod. (II), with exclusion of air, followed by activation of the pyrolysis prod. The novelty is that (II) consists mainly of inorganic waste prods., including heavy metals imparting catalytic properties, pref. with concns. of 0.1-5.0 Ti and 0.1-5.0% V, and also organic processing residues. The material contg. heavy metal consists of by-prods. such as electroplating sludge, red mud from the Al industry and filter dust from metallurgy. The fraction of carbonaceous waste prods. is high enough to give (I) with a C content of over 50 (units not stated). To enhance the active components, (I) is treated with acid solns. contg. salt, pref. obtd. from waste prods. contg. metal, and heated to fix these components. USE/ADVANTAGE - (I) is useful in waste gas purificn. It is cheap, has an ignition temp. of over 450 deg.C, has high absorption capacity for SO2, other acid gases and heavy metals and also catalyses the reaction of NH3 with NOx to N2, which proceeeds at a high rate at temps. below 180 deg.C. (I) also has high mechanical and thermal stability and resistance to O2 and hence can be regenerated several time