Short contact time thermal cracking of carbonaceous wastes to alpha olefins

A continuous short contact time thermal cracker was constructed and operated to investigate the production of alpha olefins in the C-9-C-16 range. Alpha olefins in this range are normally used as chemical feedstocks for lubricants, surfactants, alcohols and other valuable commodities. The CETC unit was operated at 100 g h(-1) between 495 and 570 degrees C using paraffin wax, waste wax from a gold refinery, waste plastic-derived oil and topped waste plastic-derived (wax enriched) oil. The effect of operating temperature, heavy ends recycle rate and feed types on the production of alpha olefins was examined in detail. It was found that the concentration of heavy paraffins with carbon numbers greater than C-16 in the heavy ends recycle stream is a good indicator for estimating the concentration of alpha olefins in the C-9-C-16 range. It was shown that feed type is the most critical factor in determining high alpha olefins yield in this range. Following is the order of suitability for producing alpha olefins in the C-9-C-16 range: paraffin wax > plastic-derived oil (topped) > plastic-derived oil (as received),waste wax. (C) 1999 Elsevier Science B.V. All rights reserved.