Coupling Red-Mud Ketonization of a Model Bio-Oil Mixture with Aqueous Phase Hydrogenation Using Activated Carbon Monoliths

摘要

A two-stage catalytic process for converting model bio-oil oxygenates (acetic acid, formic acid, acetol, and levoglucosan) to higher value compounds was conducted. Ketonization using iron oxide catalysts prepared from red mud was implemented in a packed bed reactor system using fast pyrolysis oil model compounds (stage one). High levels of acetone (1525 g/L), 2-butanone g/L), and cyclic ketones (9-13 g/L) were observed. Time-on-stream studies (7 h) indicated no measurable decline in conversion of acetol, formic acid, and levoglucosan and only a 4% decline in acetic acid conversion. Subsequently, a second stage continuous hydrogenation of the ketonization products was conducted using Pd on activated carbon monolith (ACM) catalysts generated from wood and Pd-C granules. The best results were achieved using the Pd-ACM catalyst at 180 degrees C and 300 psi (H-2), which converted ketones to alcohols at similar to 60-80%. The Pd-ACM catalyst achieved higher space time yields, selectivity, and conversions compared to Pd-C granules.