Review on coal direct liquefaction research

The gap between national and international research level is compared.Fifteen new and old processes are classified and compared,and it is found that successful liquefaction processes all accord with the structural characteristics of coal molecule.Quick liquefaction at high temperature is a direct liquefaction scheme based upon the characteristics of coal molecule,which opens a new research field.In theory,it provides the possibility to achieve the highest liquefaction efficiency and the lowest liquefaction cost,and aromatic compounds and fuel oils could be produced jointly.