Abstract: In view of the shortage of ethylene feedstock and C4 excess in refinery, the pyrolysis performance of light hydrocarbon and refinery C4 feedstock was studied by using a small steam pyrolysis simulation experimental device. The effect of C4 addition and process parameters on the yield of triene (ethylene + propylene + butadiene，the same below) in SC-1 pyrolysis furnace was investigated. The experimental results show that the optimum mass fraction of C4 is 10%－20%, the suitable pyrolysis temperature is 840－850 ℃, and the dilution ratio (mass ratio of deionized water to feed oil) is 0.5, the yield of ethylene is 30.19%－31.87%, the yield of propylene is 16.57%－18.20%, and the yield of triene is 53.60%－53.77%, respectively. It can be seen that the co-pyrolysis of C4 and light hydrocarbon not only expands the feed source of ethylene, but also increases the added value of C4 products.

Key words: light hydrocarbon, refinery C4, co-pyrolysis, ethylene, propylene, butadiene