Upgrading Coal Liquids to Gas Turbine Fuels. 2. Compatibility of Coal Liquids with Petroleum Fuels

Abstract

disproportionation are equally possible as there is a considerable amount of olefins and saturated hydrocarbons in the products.The degree of cracking may be judged by the presence of gases and fractions lower than Cio in the liquid distillate. On this consideration, it should be assumed that practically no cracking takes place at 200 °C, and very slight cracking at 300 °C. From the estimation of the Cio fraction (uncracked pcymene), we presume that the most efficient cracking is performed at 500 °C by a catalyst aged at 500 °C.There are increasing quantities of uncracked p-cymene in the products in the case of catalyst aged at 600,800, and 1000 °C. These catalysts have been reported to be poor in acid centers. Declining efficiency in cracking in their case is therefore a proof of the influence of acid centers on catalytic activity. It may then be argued why catalysts aged at 200 °C and which have been reported to abound in acid centers fail to crack the hydrocarbon oil. It is because acid centers are not the only criteria, but the temperature also should be sufficiently high to crack the hydrocarbons.A comparison between thermal and catalytic cracking shows that the latter is more efficient. The major product of thermal cracking was toluene. The liquid products in the catalytic cracking ranged over C7-C9 fractions. Similarly unsaturated fractions predominate in the gaseous products of catalytic cracking while saturated gases predominate in thermal cracking.Literature Cited