Extraction of oil-products from oil sludge with the use of liquid and supercritical fluid extraction processes with propane-butane extractant

The authors present the results of implementation of liquid and supercritical fluid extraction processes with the purpose of extracting oil products from oil sludge. A mixture consisting of propane (75 wt%) and butane (25 wt%) has been applied as the extractant. Initial oil sludge has been characterized by the absence of water and the content of solids in amount of 12.05% by weight. The extraction processes have been carried out in the temperature range of 85–160°C and pressure range of 5–50 MPa.