ABSTRACT
Crude oils foam when mixed with air and require the use of antifoaming agents. During crude oil separation and distillation, different petroleum fractions were reported to foam. The literature reported that the ‘‘foam flooding’’ observed in distillation towers was not related to any specific contaminants found in crude oils (Ross, 1987). The 60N and 150N lube oil distillates were reported to foam and their foaming tendency was reported to increase with an increase in their viscosity. With an increase in the temperature and a decrease in viscosity, their foaming tendency decreased (Butler and Henderson, 1990). Hydrofining, used as the last processing step, was found not effective in decreasing the foaming tendency of solvent refined mineral and hydroprocessed lube oil base stocks. The use of lube oil base stocks in formulated lubricating oils requires the use of antifoaming agents to meet the product specifications.
