Synthesis and performance of mesoporous iron oxide in vacuum residue slurry-phase hydrocracking

In order to develop a high-efficiency iron oxide catalyst for the slurry-phase hydrocracking of poor heavy oil, the mesoporous iron oxide was successfully synthesized by using the waste wood powder as a template, and the influence of alkali concentration in the resulting solution on crystal phase, morphology and pore structure of the synthesized samples was investigated. The crystal phase of the synthesized iron oxide transfers from alpha-Fe2O3 to gamma-Fe2O3, and their crystal sizes gradually decrease with an increase of alkali concentration based on the XRD and HRTEM results. Additionally, the iron oxide with mesoporous structure, larger surface area and pore volume is obtained at the higher concentration of alkali in solution confirmed by N2 adsorption-desorption analysis. The assessment result of the iron oxide catalyst employed in the slurry-phase hydrocracking of vacuum residue (VR) illustrates that the yields of gasoline and diesel distillates obtained over Fe-O-B20, Fe-O-B24 and Fe-O-B30 cata-lysts are higher compared with those over Fe-O-B2 and Fe-O-B14 catalysts, it can be attributed that more exposure Fe active sites derived from their larger surface area and pore volume availably improve the catalyst hydroge-nation activity, which can inhibit the over-cracking reaction of intermediate products and the condensation of polycyclic aromatic hydrocarbon in VR to enhance the yields of gasoline and diesel distillates.

Automated summary

In this study, a high-efficiency mesoporous iron oxide catalyst was synthesized and the influence of alkali concentration on its crystal phase, morphology, and pore structure was investigated. The application of this catalyst in the slurry-phase hydrocracking of heavy oil led to an increase in the yields of gasoline and diesel distillates.