CPC Subgroup
C10G 21/006 Full Title
Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents (C10G17/00, C10G19/00 take precedence)
C10G 21/006 Refining of hydrocarbon oils, in the absence of hydrogen, by extraction with selective solvents (C10G17/00, C10G19/00 take precedence)