The Combustion Characterstics of Coal in Oil Fuels

Western Europe's heavy dependence on imported energy, principally oil, is a recent occurrence. Before and during the 1940's, ninety percent of the energy demand was satisfied by indigenous coal sources, but in the 1950's and 1960's, the increasing availability of abundant, cheap supplies of crude oil caused a major shift in the energy pattern. Until the rapid escalation of oil prices from 1973 onwards, oil had achieved a penetration of nearly sixty percent of the total Western European energy demand. This resulted from the widespread conversion of coal-fired plant to oil, and the subsequent installation of efficient oil-designed plant as the economics became favourable. The coal to oil conversion programme encountered certain technical problems but these were solved by relatively simple plant operation changes. Since 1974 the economics of oil as an industrial fuel has altered adversely compared with coal, and conversion back to coal would in many cases be economically attractive were it not for the massive technical and operational difficulties and (in the steam raising market sector) the likely downrating of steam generating capacity to alleviate some of the worst problems. For many reasons, therefore, an oil fuel containing a significant coal content could provide a short to medium term prospect for firing coal in oil-designed plant, and this possibility is being actively explored within the British Petroleum Company Ltd. A task force, Coal Oil Fuels, has been set up with technical backing from the BP Research Centre, Sunbury-on-Thames,to assist in the development and exploitation of coal containing liquid fuels. A number of tasks, namely some concerning the detailed study of the combustion characteristics of the prototype fuels in semi-industrial scale furnaces have been subcontracted to the International Flame Research Foundation and have been defined and executed in collaboration between Sunbury and IFRF staff using facilities situated in Umuiden, The Netherlands. This paper briefly discusses the characteristics of the prototype fuels and describes some results from a series of trials being made by the IFRF. The first experimental results described here were obtained during the first half of 1981.