Treatment of coal liquids

摘要

Coal liquids are rendered compatible with petroleum liquids by selective oxygen alkylation or oxygen acylation of weakly acidic protons such as phenolic and carboxylic functionalities by means of a phase transfer reaction. Phenolic and carboxylic functional substituents, which are very polar, are converted to relatively non-polar ethers and esters, respectively. The O-alkylation or O-acylation is carried out in a binary liquid phase solution (organic/water). A quaternary ammonium or phosphonium salt is reacted with alkali or alkaline earth base (caustic) to produce the corresponding quaternary ammonium or phosphonium base (an example of a phase transfer reagent). This quaternary base is non-nucleophilic and readily removes the phenolic and carboxylic protons, but does little else to the coal liquid molecules. After the removal of the weakly acidic protons by the quaternary base, the phenoxides and carboxylates which are produced then undergo O-alkylation or O-acylation. The alkylating or acylating agent comprises a carbon-bearing functionality and a displaceable leaving group. The O-alkylation or O-acylation reduces hydrogen bonding and therefore polarity, thereby rendering coal liquids more compatible with petroleum liquids.