(552a) Production of Hydrocarbons from Fast Hydropyrolysis of Lignin at Atmospheric Pressure Promoted By Nickel inside Carbon-Nanotube Reactors

We present results obtained with a novel catalyst which promotes production of liquid hydrocarbons from lignin in a single stage at atmospheric pressure. The conversion can be accomplished by catalytic hydropyrolysis of lignin over Ni-loaded carbon nanotubes (CNTs). We report that the position of the nickel catalyst at the carbon nanotubes (inside or outside CNTs) play a very important role in the process. The nickel inside the CNTs led to confinement effects that significantly improved the yields of hydrocarbons compared to results obtained with Ni outside the CNTs. We also evaluated the effect of the nickel loading and the catalyst-to-lignin ratio. The total yield increased with the catalyst-to-lignin ratio and Ni loading.

The condition that maximized the yield (12.53 %) was the 20:1 catalyst-to-lignin ratio with 15 wt % Ni loading. The most abundant aromatic compounds were benzene, toluene, xylene, and indene. The most abundant aliphatics compounds were alkanes, alkene, cycloalkanes and alkanols. Aromatics and aliphatic compounds are important components of jet fuels. Given the well-known difficulties in thermal processing of lignin, the results of this work obtained at atmospheric pressure provide a promising route for the direct conversion of lignin into drop-in transportation fuels.