Renewable jet fuel range cycloalkanes from integrated catalytic processes of lignocellulosic biomass

Abstract.

A novel pathway was investigated to produce jet fuel range cycloalkanes from intact biomass. The consecutive processes for converting lignocellulosic biomass into jet fuel range cycloalkanes principally involves the use of the well-promoted ZSM-5 in the process of catalytic microwave-induced pyrolysis and Raney nickel catalysts in the hydrogen saving process. Up to 24.68% carbon yield of desired C8 – C16 aromatics was achieved from catalytic microwave pyrolysis at 500 °C. We observed that solvents were not bystanders in the hydrogenation of naphthalene; the optimum result for maximizing the carbon selectivity (99.9%) of decalin was from the reaction conducted in the n-heptane medium. The recovery of organics could reach ~94 wt% after the extracting process. These aromatics in the n-heptane medium were eventually hydrogenated into jet fuel range cycloalkanes. Various factors were employed to determine the optimal result under mild conditions. Increasing catalyst loading, reaction temperature, and prolonged time could enhance the hydrogenated reactions to improve the selectivity of jet fuel range cycloalkanes. Three types of hydrogenated catalysts (NP Ni, Raney-Ni 4200, home-made Raney nickel) were chosen to evaluate the catalytic performance. Results indicate that the home-made Raney nickel was the optimal catalyst to obtain the highest selectivity (77.46%) of jet fuel range cycloalkanes. Integrating catalytic processes of lignocellulosic biomass potentially paves a new avenue for the development of green bio-jet fuels over inexpensive catalysts under the mild conditions.