Development of a techno-economic process for organo refining of coal

An improved organo-refining process to produce low ash clean coal from high ash coal, in particular suitable for metallurgical applications, the method comprising the steps of:

• mixing coal, solvent and a co-solvent thoroughly in a system designed to implement the process, the mixing being taken-up to produce a coal slurry in a feed preparation zone of the system;
• feeding the slurry to a reactor by pumping, wherein the reactor maintains a temperature of about 200° C. to 300° C. and a pressure of 1.5 atm. to 5 atm.;
• allowing a residence time of the coal-solvent slurry in the reactor of about 1 hr to 1.5 hr depending upon predetermined process parameters;
• extracting a coal-solvent mixture after having settled the slurry in the reactor;
• feeding the extracted coal to a flasher unit;
• recovering about 30% of the solvent from the flashing unit, the remainder being a heavy material;
• feeding the remaining heavy material with some coal extracts including some amount of coal extract left at the bottom part of the flashing unit to an evaporator;
• extracting about 60% of solvent from the evaporator, the remainder being a residue;
• discharging the residue from the evaporator to a precipitator having water which acts as an anti-solvent to produce a coal slurry;
• filtering the slurry in a rotary drum to produce a super clean coal residue and a filtrate;
• collecting the super clean coal residue containing 0.1 to 10% ash;
• feeding the filtrate containing water and an organic material mixture into a distillation unit;
• and
• separating the water and the organic material in the distillation unit, in order to recover at least 7 to 8% of the remaining solvent.