Reaction performance and product properties of catalytic pyrolysis of HGO (heavy gas oil) and LGO (light gas oil) derived from Canadian synthetic crude oil were investigated in a riser unit.The yield of total light olefins (ethylene

propylene

and butylene) showed a maximum with increasing reaction temperature and catalyst-to-oil mass ratio

decreased with increasing reaction time

and enhanced with increasing steam-to-oil mass ratio.The optimal reaction temperature

catalyst-to-oil mass ratio

reaction time and steam-to-oil mass ratio of catalytic pyrolysis of HGO were 620—640℃

16

2 s and 0.5

respectively.Under these optimal reaction conditions

the yields of ethylene

propylene and total light olefins reached 9.0%（mass）

15.8%（mass） and 32.6%（mass）

respectively.There were large amounts of aromatics in pyrolysis gasoline

diesel and heavy oil fractions.Gasoline fraction contained above 80%（mass） of aromatics which were mainly toluene and C8 aromatics.Diesel fraction contained above 60%（mass） of aromatics which were mainly single-ring and double-ring aromatics.Heavy oil fraction contained above 70%（mass） of aromatics which were mainly multi-ring aromatics.