PROCESS

摘要

PROCESS Exhaust gases from two-stroke (two-cycle) internal combustion engines which contain relatively high concentrations of carbon monoxide and hydrocarbon are catalytically treated to purify the exhaust gases and thus decrease pollution of the atmosphere. The catalytic treatment is conducted such that the relatively high concentrations of carbon monoxide and hydrocarbon in the exhaust gases can be reduced without deleteriously affecting the catalyst. The exhaust gases are passed to a first catalyst zone which contains insufficient catalyst for complete combustion of the carbon monoxide and hydrocarbon, and the first catalyst zone does not reach temperatures which are deleterious to the catalyst. The effluent from the first catalyst zone contains combustible values and is cooled and passed to a second catalyst zone, said cooling being sufficient to avoid reaching temperatures in the second catalyst zone which are deleterious to the catalyst.