Sorption and recovery of heavy oils by using exfoliated graphite Part II: Recovery of heavy oil and recycling of exfoliated graphite

Recovery of heavy oils sorbed into exfoliated graphite could be performed by filtration under mild suction at room temperature, but sorption capacity of exfoliated graphite was found to decrease markedly with its recycling. Heavy oils which were spilled into water and recovered by using exfoliated graphite could not be differentiated from the original in molecular weight and chemical constitution. From the measurement of water content in heavy oils spilled and recovered, exfoliated graphite was found to sorb oil preferentially. Therefore, it was concluded that there will be no problem to recycle heavy oils after recovering them using exfoliated graphite, though the recycling of exfoliated graphite reduced its sorption capacity markedly.