Study On Methods Of Oil Recovery From Waste Oil Sands

As an unconventional oil source, oil sands from the Buton Island, Indonesia, were processed torecovery oil. A series of studies on methods of recovery oil were conducted and some processingtechnologies, such as solvent extraction, recycling solvents, turning tailings into wealth, were obtained.These experimental data and methods are very important to develop and utilize oil sand in the future.The property of oil sands from the Buton Island was determined in organic solvent extraction tests.The influence of some factors including solvent properties, solvent to oil sand ratio, polar organic solventsand temperature was investigated. It was shown that toluene to heptane ration had an influence on recoveryand product quality. The separation was better when the ratio of toluene to hexane was1/5after settling10min, while the settling time was30min with the ratio of toluene to hexane1/1. Bitumen recovery wasobviously improved when polar organic solvents (MEK and MIBC) were added.The characterization results showed that the solids isolated from supernatant and tailings wereassociated with a certain concentration of organic matter. The elements N, S were observed on the surfaceof solids. Product quality was affected since sands with high content of organic matter and clay mineralswere more preferentially to enter the extracted bitumen-solvent.The extracted bitumen-solvent included some fine sands, which resulted in increasing of ash contentand low quality of bitumen product. Methods of improving bitumen quality and the effectiveness of settlingwith the flocculant were studied. The solution of resorcinol (40%) was the effective flocculant and the ashcontent of bitumen could be decreased below0.5%with flocculant to oil sand ratio of0.05.This paper investigated the extraction effectiveness of some available, economic and practical solventsin two-steps extraction process. It was showed that bitumen recovery reached96%when the mixturesolvent of naphtha and cyclohexane was used. The paper also put forward methods of treating tailings withhydrochloric acid and producing industrial calcium chloride. The percent conversion of tailings was above75%and insoluble sands were aluminosilicates and clays.