LIQUEFACTION OF CALCIUM-CONTAINING SUB-BITUMINOUS COALS AND COALS OF LOWER RANK

摘要

ABSTRACT OF THE DISCLOSUREA process for the treatment of a calcium-containing sub-bituminouscoal and coals of lower rank to form insoluble, thermally stable calcium saltswhich remain within the solids portions of the residue on liquefaction of thecoal, thereby suppressing the formation of scale, made up largely of calciumcarbonate, e.g., vaterite, which normally forms within the coal liquefactionreactor (i.e., coal liquefaction zone), e.g., on reactor surfaces, lines,auxiliary equipment and the like. An oxide of sulfur, in the vapor phase, iscontacted with a coal feed sufficient to impregnate the pores of the coal.The impregnated coal, in particulate form, can be liquefied in a coal lique-faction reactor (reaction zone) at coal liquefaction conditions without sign-ificant formation of vaterite or other forms of calcium carbonate scale onreactor surfaces, auxiliary equipment and the like.