PROCESS FOR TREATING COAL TO IMPROVE RECOVERY OF CONDENSABLE COAL DERIVED LIQUIDS

摘要

A method for treating coal includes drying coal in an initial drying step. The dried coal is pyrolyzed in a pyrolysis step to form coal char and evolved gases. The coal char is eventually cooled and blended. The evolved gases are condensed in at least two, preferably three or more, distinct zones at different temperatures to condense coal-derived liquids (CDLs) from the evolved coal gas. Noncondensable gases may be returned to the pyrolysis chamber as a heat-laden sweep gas, or further processed as a fuel stream. The CDLs may optionally be centrifuged and/or filtered or otherwise separated from remaining particulate coal sludge. The sludge may be combined with coal char, optionally for briquetting; while the CDLs are stored. Precise control of the condensing zone temperatures allows control of the amount and consistency of the condensate fractions collected.