Green-aromatic production in typical conditions of fluidized catalytic cracking

Abstract

The production of green hydrocarbons in the standard refinery has significant potential to reduce our reliance on oil and shorten the path to sustainability. Second-generation biomass can help to achieve this objective yet presents important drawbacks. It is majorly composed of reactive compounds and features low density. These features could be overcome by previously transforming the biomass by ketalization reaction into a bio-crude mainly composed by ketal-sugar derivatives. In this work, a representative compound of the bio-crude class, i.e. 1,2:3,5-di-O-isopropylidene-α-d-xylofuranose (DX) were used in up to 50 wt% mixtures in n-hexane was converted in a laboratory scale fluidized catalytic cracking (FCC) reactor. A commercial and a simplified FCC catalyst were used. Converting a mixture of 30% DX in n-hexane in the presence of a commercial catalyst gave 42.3% aromatics in the liquid product, while pure n-hexane gave merely 8.9%. The use of deactivated catalysts further reduced the coke yield to half of the fresh one. The nature of the coke on the spent catalyst is exclusively composed by carbon and hydrogen, demonstrating that DX is easily deoxygenated. The n-hexane conversion slight reduced in the presence of DX, and did not reduce the stability of the catalyst through micropore blocking. This work demonstrates that adding DX allows to contributes to high gree-aromatic production in FCC and that products distribution is remarkably affected by the type of catalyst used.