Synergistic Process for FCC Light Cycle Oil Efficient Conversion To Produce High-Octane Number Gasoline

Light cycle oil (LCO) from fluid catalytic cracking (FCC) was treated by selective hydrogenation and then cracked in a FCC apparatus. Compared with LCO, hydrogenated LCO (hydro-LCO) exhibited remarkable FCC performance, recording with that 50.83 wt % hydro-LCO was converted into gasoline fraction. This is attributed to the reduction of aromatics in hydro-LCO, especially for the multiring aromatics. After hydrogenation, the amount of multiring aromatics significantly decreased from 63.2 to 9.5 wt %, while naphthenoaromatics (including indans, tetralin, and indenes) increased from 8.8 to 34.2 wt %. In accordance with the experimental results and theoretical analysis of LCO reaction characteristics, a synergistic process for LCO efficient conversion to high octane number gasoline was proposed, and simulation experiments were carried out. The results show that, compared with routine FCC, 20 wt % higher conversion and 16 wt % more gasoline could be obtained. Moreover, gasoline from synergistic process exhibited decreased sulfur and olefins, but increased aromatics, and thereby improved octane number. These findings indicate that the proposed synergistic process could be an effective option for producing gasoline with high octane number.