Abstract
Waste engine oils can be cracked at high temperatures to produce olefin-rich oils. The olefins cause instability in the resulting gas oil; they tend to polymerize and form tarry deposits. Possible acceptable recycling and re-refining processes of waste lubricant oil are cracking and pyrolysis. The cracking process yields a highly unstable low-grade fuel oil, which can be acid-corrosive, tarry, and discolored, along with a characteristically foul odor. Catalytic cracking breaks complex hydrocarbons into simpler molecules in order to increase the quality and quantity of lighter, more desirable products and decrease the amount of residuals. Pyrolysis appears to be a technique that is able to reduce a bulky, high-polluting industrial waste, while producing energy and/or valuable chemical compounds. The yields of liquid products, called waste oil gasoline, increase with increasing temperature. The yield of liquid product sharply increases between 570 K and 620 K in an alumina catalytic run. The yields from alumina catalytic pyrolyses were 6.6, 14.7, 22.2, and 41.8% at 275, 505, 569, and 620 K, respectively. Octane number of the waste oil gasoline (96) is higher than that of gasoline (89). Flash point of waste oil gasoline (245 K) is lower than that of gasoline (249 K).