Characteristics of American coals in relation to their conversion into clean energy fuels. Quarterly technical progress report, January--March 1977

Abstract

Twenty-one coal samples have been added to the Penn State/ERDA Coal Sample Bank. Ninety-six sets of analytical data and 114 coal samples were provided upon request to other agencies engaged in coal research. Mass spectrometer and reactor systems have been used successfully in measuring the amount of vaporization (and pyrolysis) products of hydrocarbons in low concentrations in a helium carrier gas. Research has shown, using small angle x-ray scattering, that the pore structure of a char is a function of the rank of the parent coal and maximum heat treatment temperature. Carbon deposition on chars from the cracking of methane decreases subsequent reactivity of the char to air. The decrease in reactivity appears to be due to a decrease in active surface area and deactivation of catalytic impurities. Experimental results previously obtained concerning the combustion of char and anthracite have been analyzed with respect to a simple theory of radiative flame propagation and the computer model has been used to investigate the effects of fuel particle density variations. In the study of the combustion characteristics of coal-oil-water emulsions, furnace efficiency peaked at about 5% coal addition, at 10% water, and 20% excess air.