Cleaning of lubricant-oil-contaminated plastic using liquid carbon dioxide

Abstract The feasibility of using liquid carbon dioxide for cleaning contaminated plastics was evaluated. Flow sheets for the CO 2 cleaning processes have been conceptualized and the material and energy balances were conducted using ASPEN Plus. The average % lubricant oil in waste plastics was found to be 2.49%. Although the CO 2 cleaning process with hexane as a co-solvent resulted in a higher cleaning efficiency than the process without co-solvent, it consumed 2.2 times more energy. Based on cleaning 30 kg of plastics, the operating cost of the process with hexane was 5.7 times higher than that of the process without hexane.