Abstract: In order to expand the feedstock scope for ethylene production via steam cracking, Daqing Gulong shale oil was used as the research object.The main physicochemical properties of light and middle distillates of shale oil, as well as the naphtha fraction and second side distillate of conventional crude oil, were compared.The steam cracking process conditions were optimized using a small scale simulation evaluation device. The effects of raw material composition, cracking temperature and dilution ratio (the mass ratio of steam to feed oil) on the yield of olefins were investigated, and the corresponding influence mechanism was analyzed in depth.The results show that the steam cracking performance for olefin production of both the light distillate and middle distillate of Daqing Gulong shale oil is superior to that of the corresponding distillates from conventional crude oil, indicating that this shale oil is an excellent feedstock for olefin production via steam cracking.The optimal steam cracking temperature for the light distillate of shale oil is 840 ℃ with a suitable dilution ratio of 0.6. Under these conditions, the ethylene yield and total yield of ethylene, propylene and 1,3-butadiene reach 33.37% and 53.43%, respectively.For the middle distillate of shale oil, the optimal cracking temperature is 820 ℃ and the suitable dilution ratio is 0.8, under which the total yield of ethylene, propylene and 1,3-butadiene is as high as 57.09%.The performance of mixed steam cracking of shale oil fractions and conventional crude oil fractions is superior to that of cracking the corresponding conventional crude oil fractions alone, but inferior to the linear weighted performance of cracking them separately.

Key words: shale oil, steam cracking, ethylene, blended oil