Sources of Used Oil Samples Ⅰ
Automotive used oils, including engine crankcase oil, diesel engine oil, and hydraulic brake, transmission, power steering fluids, constitute a large portion of used oils. Sources of used automotive oils are do-it-yourself oil changers (DIYers), service stations, repair and maintenance shops, vehicle dealers, truck and taxi fleets, military installations, and industrial/manufacturing facilities. Another main category of used oils is industrial used oils, which include lubricating oil, hydraulic fluids, grease, and process oils. In most 57 lubricating and industrial applications, the oil must be replaced by new oil when the performance of the oil deteriorates over time as additives break down and contaminants build up. The fraction of the new oil that becomes used oil varies widely for different applications. For example, only 10 percent of industrial process oils sold, in comparison to 90 percent of electrical transformer oils, are generated as used oil. The used oil generation rate for automotive oils is about 60 percent, which is a little bit higher than 52 percent for industrial oils. The recycling rate for automotive oils (≈ 60 to 70 percent), however, is much higher than that for industrial oils (≈ 25 to 40 percent).