Light Products and H2-Rich Syngas over the Bifunctional Base Catalyst Derived from Petroleum Residue Cracking Gasification

Vacuum residue is utilized by a process involving the residue cracking and coke gasification regeneration. In this process, vacuum residue is first converted into the products of light olefins and light oils by catalytic cracking, and then the cracking-generated coke is gasified into H2-rich syngas by using a bifunctional base catalyst. Their cracking gasification effects of vacuum residue are studied in a dual fluidized bed reactor. The results show that the solid base catalysts could enhance light olefin yield (have high olefinicity) and inhibit the formation of coke in comparison with silica sand and a hydrothermal treatment zeolite catalyst (FCC catalyst). Furthermore, the catalyst prepared at a CaO/Al2O3molar ratio of 12:7 displayed a better cracking effect than the one produced at the molar ratio of 1:1. The effects of the reaction temperature and the catalyst-to-oil ratio on the distribution of cracking liquid from vacuum residue solid base cracking are discussed. The results showed that the heavy oil conversion of more than 93.0%, the light oil yield of about 81.0 wt %, the coke of ca. 5.2 wt %, and the C2–C3 olefinicity of higher than 53.0% are achieved by cracking at 700 °C with a catalyst-to-oil ratio of 7.0. The coke over solid base catalyst is well gasified at 800 °C in an atmosphere of steam–oxygen. The content of H2is about 55.5 vol % and with the CH4content of less than 0.2 vol % in comparison with 36.6 and 2.4 vol % over the FCC catalyst, respectively. The cracking effects of solid base catalysts are stable via a few cycles process, although a decrease in catalytic effect is observed.