Biohydrocarbons Production under Standard Refinery Conditions by means of a Representative Ketal Compound of Biocrude

摘要

Any standard oil refinery is based on mature processes that have been adapted to poorly reactive hydrocarbon feeds. In contrast, biomass-derived compounds are highly functionalized and reactive compared to hydrocarbons. The goal to connect these two different chemical worlds is simple: to transform biomass by ketalization under mild conditions (approximate to 120 degrees C) to afford a biocrude that is composed of ketal derivatives; 1,2:3,5-di-O-isopropylidene--d-xylofuranose (DX) is present in the range of 20-30wt in biocrude. Herein, DX mixed in n-hexane was used as a model under cracking and hydrotreatment conditions. A mixture of DX up to 30wt in n-hexane was converted at 500 degrees C in fixed-bed reactor under continuous flow using ZSM-5 and USY zeolites as catalysts. Remarkably, ZSM-5 was able to convert DX into monoaromatics. At 1.5min residence time, 64-94 of DX was converted into monoaromatics. Additionally, ZSM-5 showed a coke yield lower than 4wt. In contrast, USY increased the coke yield by 10-fold and afforded fewer monoaromatics. A DX mixture up to 30 in n-hexane was converted fully by hydrotreatment in a fixed-bed reactor using Pd-USY as the catalyst at 300 degrees C and 30bar to produce saturated hydrocarbons only up to 12atoms. C-13-labeled DX (in all C-13-xylofuranose) showed indubitably that xylofuranose carbon atoms were converted into hydrocarbons.