Catalysis of coal conversion at mild temperatures

Abstract

Many materials have been used or tested as catalysts for the direct conversion of coal to liquids. However, the factors which determine whether a particular substance will be an excellent, fair or poor catalyst, or an inhibitor, are still not understood. Most of the catalyst studies have been of empirical nature and neither the specific catalytic mechanisms nor the exact forms responsible for the catalytic effects observed have been elucidated. In studies on the catalytic action of Lewis acids for the liquefaction of coal, many properties of these materials were correlated. After testing more than eighty catalysts, only one property was found to directly correlate with the yield of liquefaction products in coal conversion experiments. This property was found to be the electronic softness of the Lewis acids studied. Results from mild liquefaction experiments on bituminous coal have been obtained and give insight into the reactions taking place and the moieties involved in most of the liquefaction reactions.