Residence time measurements in a coal hydrogenation process

Abstract

Residence time of coal in the University of Utah “coiled tube” coal hydrogenation reactor has been measured. This has been done with an electronic device which detects a tracer (usually iron) as it passes specific places at the beginning and end of the reactor. The measured coal solids residence time in the reactor has varied from a few seconds to a few minutes. Calculated vapor and gas residence times are one or two seconds. Short vapor residence time terminates further hydrogenation of vapors and thus reduces gas production and hydrogen consumption. The relatively longer coal solids residence time permits further hydrogenation which increases liquid yields.