Stabilizing Effect of Nonionic Surface Active Agents on COM

Abstract

Coal and oil mixture (COM) can be handled in a manner similar to liquid fuels and can reduce the consumption of oil to the half of its level, and provides one of an ideal fuel to oil.This paper will discuss the stabilizing effect of various additives on COM prepared by the wet type COM preparation method by which coal is pulverized in C heavy oil in a ball mill.Without additives, all COM is unstable regardless of types of coals (bituminous coal, subbitumi-nous coal or lignite) and shows settling of coal particles and coagulation only after they are stored still for a period of I week at 70°C.In this present experiment, Miller coal of Australia origin (bituminous coal) and C heavy oil of the Middle East origin were used to obtain a typical COM preparation, and various nonionic surface active agents were added to evaluate their stabilizing effect into COM.The result showed that either a multi-branched high molecular nonionic surface active agents of copolymer of propylene oxide and ethylene oxide obtained from sorbitol as starting substance, or the tolylenediisocyanate cross-linked product of the above copolymer would provide a stabilizing effect on COM. On the contrary it was found that low molecular nonionic surface active agents or straight-chain nonionic surface active agents have no stabilizing effect.