Characterization of mineral matter in coals and coal liquefaction residues. Annual report

Abstract

One of the major aims of this program is to characterize organic and mineral components of coals and coal liquefaction residual materials. Relationships are sought between composition and properties of these components and the behavior of specific coals during liquefaction processes. Results show that the residual materials are made up of various organic and inorganic components. The organic phase of these materials is comprised of unaltered or partly reacted coal macerals and carbonaceous slids formed by retrogressive reactions during processing. Inorganic components are coal minerals, pyrrhotite and, in the case of liquefaction and subbituminous Wyodak coal, calcium carbonate precipitates. The exact distribution of all these components is a function of feed coal, and processng conditions (H-Coal or Solvent Refining). Studies have been made into factors which influence retrogressive reactions during Solvent Refining. In the absence of a hydrogen donor, short contact times SRC's form semi-coke more readily than do equivalent long contact time SRC's. Experiments with SRC fractions show that the propensity to undergo retrogressive reactions is strongly influenced by phenolic oxygen functionality and molecular weight. Semi-coke formation is markedly inhibited by hydrogen transfer either by added hydrogen donors or compounds which can shuttle hydrogen. The techniques developed by thismore » project have potential as a means of diagnosing problems or inefficiencies in plant or equipment operation.« less