Temperature dependence of heavy oil sorption on exfoliated graphite

The seriousness of oil spill accidents from oil tankers at sea depends on several factors, such as the amount of spilled oil, or the season. The temperature dependence of the heavy oil sorption on exfoliated graphite must examined to asses the effects of the weather or the season. Sorption decreased with decreasing temperature. The maximum sorption amount of an A-grade heavy oil changed a little with temperature, from 90 g/g at 30 degreesC to 80 g/g at 0 degreesC. The maximum sorption amount of crude oil was 60 g/g even at 0 degreesC. The maximum sorption amount of a B-grade heavy oil was 40 g/g at 0 degreesC. The maximum sorption amount decreased most remarkably for a C-grade heavy oil with decreasing temperature, and no sorption was observed at temperatures lower than 15 degreesC. This change of maximum sorption amount on exfoliated graphite with temperature is related with the viscosity change of the oils.