Patent ID: 9534176
Date: 2017-01-03
CPC Classifications: C10B,C10G

Claim:
1. A method of depolymerizing coal, comprising: preparing a high temperature depolymerizing medium consisting of heavy hydrocarbon oils and mixing it with coal to form a mixture; performing a first distillation at a temperature below 250° C. equivalent atmospheric pressure to recover naphthalene; heating the mixture to a temperature between 350° C. and 450° C. for a period of at least one minute to create a digested coal slurry; optionally centrifuging the slurry to produce a centrate liquid with ash content less than 0.5% by mass; and optionally distilling the centrate liquid to produce a pitch residue with hydrogen content between 4.0% and 5.0%, and optimally with a softening temperature of about 110° C. and ash level less than 0.5% by mass.