Production of olefins via steam cracking of vegetable oils

Vegetable oils (in Europe particularly rapeseed) are the favoured raw material for production of methyl esters to be used as biodiesel. This paper discloses a possibility of their alternative utilization as crude oil substitute via vegetable oil steam cracking to produce short alkenes to be used in polyolefins production industry. During thermal decomposition under conditions matching those of gas-oil steam cracking (short residence time, temperature over 800 degrees C) vegetable oils form similar products as traditional crude-oil-based feedstocks. The yields of major pyrolysis products of various vegetable oils were determined using the apparatus employed previously to laboratory research of hydrocarbon pyrolysis and they were compared to yields obtained by cracking traditional feedstocks. Also the effects of hydrocarbon chain length and saturation of acyls forming the oils were analyzed in detail. The possibilities of processing vegetable oils by co-cracking in mixture with crude oil feedstocks are discussed and supported by experimental data. (C) 2011 Elsevier B.V. All rights reserved.