Catalytic and Thermal Pyrolysis of Atmospheric Residue

Pyrolysis of Chinese Daqing atmospheric residue on the commercial catalytic pyrolysis process (CPP) catalyst, commercial fluid catalytic cracking (FCC) catalyst, and quartz sand was investigated using a confined fluidized bed reactor system. The pyrolysis behaviors, of the commercial CPP catalyst were similar to those of the commercial FCC catalyst, while they were different from those of quartz sand. The reaction extent of the thermal pyrolysis on quartz sand was high, and the yield of total light olefins was 36.88 wt % at 660 degrees C and 41.88 wt % at 700 degrees C. The commercial CPP catalyst showed the best pyrolysis performance and obtained the highest yield of total light olefins. The use of catalysts accelerates not only the cracking reaction, but also the hydrogen transfer and isomerization reactions. Both the free radical mechanism and the carbonium ion mechanism play an important role for the catalytic pyrolysis of Daqing atmospheric residue for light olefin production.