Separating solids (ash) from liq. dissolved out of coal - by adding alcohol before solids and liq. separation, e.g. by filtration

摘要

Ash sepn. from coal comprises (1) dissolving the hydrocarbon material of coal with a hydroaromatic solvent to form a side-stream contg. a dissolved coal-recovered liq. (I), hydroaromatics and suspended solids; and (2) passing the side-stream to a solids/liq. sepn. step. Novelty lies in admixing the side-stream, before solids/liq. sepn. with pref. 0.05-15 wt.% of a 2-10 C alcohol, which forms a homogeneous compsn. with (I). Solids/liq. separation pref. takes place by filtration. Dissolution of hydrocarbons takes place pref. by standard "solvent refined coal" process (SRC-process) in which comminuted coal is dispersed in a hydroaromatic cpd.-contg. solvent, at high temp. and pressure, in contact with H2 or CO and water. The added alcohol is esp. isopropanol, n-, sec.- and/or tert. butanol. Addn. of alcohol increases sepn rate of solids from (I), e.g. from 3.2g/min. to 5.6 g/min.