Development of a Method for the Extraction of Oil from Clay by Friendly Phase Transfer Catalyst

Abstract

The separation of waste oil from clay was studied using benzyl triethanol ammonium chloride as phase transfer catalyst. The study showed that the surface tension has an effect on oil recovery. An induced air flotation process was used and polymeric decyl phenol formaldehyde ethoxylate was used as the collector. The effects of various parameters including concentration of catalyst, collector, time of flotation, contact angle, and zeta potential on oil extraction were studied. The results show that oil recovery increases with time of flotation up to a maximum and then levels off. Oil recovery is marginal if the flotation time is extended beyond 12 min. For example, oil recovery increases by only 4% for 25 g oil and 20 g surfactant in the feed when flotation time increases from 12 to 15 min. Oil recovery also increases with surfactant dosage. Furthermore, oil recovery was enhanced by controlling the interfacial tension at the oil–water and water–air interfaces. The mechanism of oil separation was discussed according to micelle composition and the calculated oil recovery obtained was 87%. Furthermore, the kinetic study proved that the process is first order and depends on catalyst concentration. Oil recovery follows a Gibbs adsorption equation. The molecular interaction parameter at the aqueous solution–air interface was also calculated. The results proved that the extraction of oil from solid phase can be conducted by adding phase transfer catalyst. Moreover, the article suggests a model of oil separation from soil according to specifications of adsorbed oil, including isoparaffin and n-paraffin that were analyzed by gas chromatography technique.