Catalyst contg. oxide of nickel or cobalt, lanthanum and opt. copper - on porous inert support, used in treating effluent contg. hypohalite

摘要

A catalyst system comprises (A) 5-20 wt.% of Ni and/or Co, as oxide, 0.2-20% of La, as oxide, and 0-20% of Cu, as oxide, with the metals forming at least 8 wt.% (calc. as elements) of the total wt. of the catalyst, and (B) a shaped, porous inert support impregnated with the metal oxides, and comprising Al203, Ca aluminate, Si02 and/or MgO, with pore vol. 0.15-0.25 cc/g and specific surface 5-25 square m/g. USE/ADVANTAGE - An effluent contg. an oxidising halogen, as hypohalite, is treated by passing the effluent, pre-heated to 50-90 deg.C, onto a fixed bed of the catalyst. The effluent may result from the destruction of chlorinated gases, e.g. Cl2, with soda, or from filtration and washing of solid hypochlorites or chloroisocyanurates, and may contain up to 20,000 ppm of Cl+ and have pH above 9. The effluent is fed at an hourly space rate of 1-30/h. ADVANTAGE - Effluents contg. up to 20,000 ppm of Cl+ can be more efficiently treated.