Hyper-coal process to produce the ash-free coal

Research and process development to produce the ash-free coal (Hyper-coal, HPC) has been carrying out since 1999. A new cost-effective process (Hyper-coal process) by the application of the solvent de-ashing technology can be adopted for the Hyper-coal process. Coal extraction rate achieved almost 70 wt.%daf (based on dry and ash-free coal) from some kinds of coals using two-ring aromatics as the recycle solvent. A gravity settling effectively removed insoluble residue from the solution. A flash separator recovered the solvent completely and produced Hyper-coal as a spherical fine particle, which containing several hundred PPM of ash. It was estimated that the calorie base cost of Hyper-coal would be competitive to a general coal price including its ash disposal cost in Japan.