GB835689A - Process for removing acetylene, methyl acetylene, and allene from hydrocarbon mixtures - Google Patents

Abstract

Hydrocarbon mixtures of C2 and/or C3 hydrocarbons are freed of acetylene, methyl-acetylene and allene by selective catalytic hydrogenation in the liquid, preferably trickling, phase. Suitable catalysts are 0.1-5% of platinum or palladium supported on a macroporous support having an internal surface area less than 50 m2/g and a water absorption capacity of at least 10%, e.g. active alumina gel, silica gel, active carbon, natural aluminium or magnesium silicate, lightly calcined clay free from iron, pumice free from iron or lightly sintered alumina or magnesia. Temperatures of - 40 DEG to 50 DEG C. can be used with throughputs of 3-40 kg. per litre of reaction chamber volume per hour. The hydrogen pressure should be sufficient to maintain the hydrocarbons in the liquid phase. High purity hydrogen is preferred in which case the withdrawal of gases is unnecessary. Catalyst poisons, particularly sulphur compounds and carbon monoxide, must be removed from the hydrogen and hydrocarbons. The reaction chamber is preferably cooled by external or internal indirect cooling with water, liquid ammonia or brine and if the starting material has high concentrations of the materials to be hydrogenated, it is preferably diluted, e.g. with part of the product, to avoid a local temperature rise at the beginning of the reactor.