AN IMPROVED WAY TO PRODUCE LOW ASH CLEAN COAL FROM HIGH ASH COAL WITH TOTAL SOLVENT RECOVERY

摘要

An improved process to produce low ash clean coal from high ash coal with substantially complete solvent recovery, the process comprising forming a slurry of coal fines in a N-Methyl-2-pyrrolidone (NMP) with a small amount of Ethylenediamine (EDA); maintaining said slurry in a reactor at a temperature range of 100�C to 240�C and a pressure range of 1 to 4 gauge (kg/cm2) for a period of about 15 minutes to 4 hours; separating the produced sample withdrawn from the reactor, separation cut size being variable depending on the particle size to be treated including application of the end product, one part being a filtrate or extract and other a reject; precipitating the coal in an anti solvent by adding concentrated extract; separating the coal by filtration, said separated coal having a reduced ash content; feeding the extracted part into an evaporator to recover 80-85% solvent; precipitating the concentrated material into an anti solvent tank to separate coal from solvent, feeding anti solvent and solvent mixture in a distillation column to separate remaining solvent from the anti solvent for reuse in the process.