Feasibility and economic analysis for supercritical CO₂ extraction of diesel from oil sands

In order to analyze the technical feasibility and economy of diesel extraction from oil sands using supercritical CO₂ as solvent. Supercritical CO₂ extraction of the long-chain alkanes of C₁₀, C₁₆, C₁₈ and C₂₀, which are the main compounds in diesel were studied. Influences of the operating prameters of pressure, extraction time, CO₂ flow rate, and effect of methanol as cosolvent were investigated. Aspen Plus software was also used to simulate the extraction efficiencies, and the results were consistent with the experiment results. Results indicated that the extraction efficiency of C₁₀∼C₂₀ could reach 95% at 35°C, 20 MPa, with a flow rate ratio of methanol to CO₂ of 0.3, and extraction time of 180 min. Technical economy of the supercritical CO₂ extraction system with a processing capacity of 20 t·d^-1 were evaluated. Results indicated that when treated the oil sands with an oil content of 21wt%, the system investment was 2.4 million dollars, with a daily revenue of 3740 dollars, and the investment can be recouped within two years.