Cleanup of Oil-Contaminated Soils of Kuwaiti Oil Lakes by Retorting

Because of the Gulf War in 1991 over 300 oil lakes formed in the Kuwait desert. The bulk volume of the oil-contaminated soils has been estimated as 18 million cubic meters. These soils threaten the environment and prohibit the development of these lands. Various methods have been proposed to clean these sands, but they have serious economical, technical, or environmental disadvantages. Thermal desorption appears to be one of the most promising technologies for application in Kuwait oil lakes. The method is based mainly on the evaporation and visbreaking of the fluids contained in the contaminated soil by heating it up to 500 600 C under atmospheric pressure. The factors that control the performance of the retorting process include temperature, oil type of occurrence, connate water, particle size and miner alogical composition of the soil, loose versus consolidated soil samples, evaporation versus thermal or catalytic cracking caused by the minerals and clays incorporated in soil, and so on. Analysis and characterization of the produced fluids were conducted. Experiments performed on samples of the oil-contaminated sands and rocks yielded potential quantities in a fairly short time of retorting. The method is low cost and has a high potential in upgrading the recovered oil. It solves also the problem of extracting oils that exist in the forms of sludge and emulsion.