Experimental study of two-stage riser FCC reactions

The concept of two-stage riser (TSR) fluid catalytic cracking (FCC) was tested in the laboratory. The goals were to improve product distribution and increase product yield. A series of FCC runs was carried out in a pilot unit. At a similar conversion level, the results showed that the TSR FCC was better than the one-stage riser (OSR). The yields of gasoline and light oil increased by 2–3% and 3–4%, respectively, and the gas decreased. The research and motor octane numbers of gasoline from the TSR FCC were higher than those from the OSR FCC by 2–3 and 1–2 units, respectively. Compared with the one-stage FCC, the gasoline produced from the TSR FCC contains less alkene and more iso-alkane.