Abstract: Spent filter clay used in the removal of contaminating organic polar-type compounds from petroleum distillates is regenerated by flushing the spent filter clay with liquid methanol and recovering and recycling the contaminated wash methanol without distillation through the filter for additional flushing of the contaminants from the clay.

Abstract: Novel insulating oil compositions comprising a major amount of an insulating oil and a minor amount of a diarylalkane.

Abstract: Novel insulating oil compositions comprising a major amount of an insulating oil and a minor amount of a product obtained as a result of a process which comprises reacting benzene with ethylene in the presence of an alkylation catalyst to obtain a reaction mixture containing largely unreacted benzene, ethylbenzene, polyethylbenzenes, 1,1-diphenylethane and heavier material, separating at least benzene, ethylbenzene and polyethylbenzenes from said reaction mixture and thereafter recovering from said heavier material a fraction whose boiling points fall within a temperature range of about 255.degree. to about 420.degree. C. as said product.