Abstract: LDO-70 catalyst was a catalyst developed for reducing olefin content of FCC gasoline．The commercia1 tria1 of LDO-70 catalyst was carried out successfully in the FCC unit of PetroChina Liaohe Petrochemical Company. Results showed that LDO-70 catalyst could significantly reduce the olefin content of FCC gasoline, when olefin content reduced 5 percentage points, the RON loss was only 0.6 units. As compared with the base case under similar operation conditions, it can be seen that the yields of gasoline and light oil increased 1.63 and 1.02 percentage points, respectively; the yields of slurry oil and coke reduced 0.99 and 0.50 percentage points, respectively; the product distributions were improved significantly．

Key words: gasoline, olefin, octane number, residue feed, catalytic cracking, catalyst