Liquefaction of coal

Claim 1

In a process for solvent refining of a low rank coal of high oxygen content by mixing a comminuted coal charge with a hydrogen donor recycle solvent derived in the process maintaining the resultant mixture at reaction temperature in the presence of elemental hydrogen for a period of time sufficient to dissolve and react components of the coal, removing normally gaseous and solid materials from the effluent of said reaction, separating a liquid fraction boiling above about 400° F., recycling said liquid fraction to provide said hydrogen donor recycle solvent and recovering a liquid fuel product from the remainder of said effluent, the improvement for providing a hydrogen donor recycle solvent of greater benefit to the process which comprises separately subjecting said low rank coal and a coal of higher rank and lower oxygen content to test dissolution and reaction in admixture with a hydrogen donor solvent under hydrogen pressure at reaction temperature, analyzing the liquid products to determine the weight percent yield of phenols boiling above about 400° F., each of said reactions based on dry weight of the respective coals, calculating a blend ratio of the said coals which will yield less than 15 weight percent of phenols boiling above about 400° F. based on dry coal, adding to said low rank coal an amount of said coal of higher rank corresponding to said calculated blend ratio to provide a blended coal and supplying said blend coal to the process as said comminuted coal charge.