Isolation and Purification of Monofunctional Methoxyphenols from Loblolly Pine Biocrude

Abstract

Methoxyphenols (MPs) are valuable chemicals in liquid intermediates from pyrolysis of lignocellulosic biomass. The use of a single technique to recover a high-purity bioproduct of MPs from pyrolysis liquid is challenging. The purpose of this study is to combine distillation and chromatography techniques in sequence to recover exclusively eugenols and guaiacols as monofunctional MPs in biocrude produced from the pyrolysis of loblolly pine with a nonzeolite alumina catalyst. A biocrude containing 11.0 wt % of the targeted monofunctional MPs was first distilled in two stages to recover an MP-rich fraction with 49.3 wt % concentration of MPs at a recovery efficiency of 86.9%. A chromatography separation using silica gel adsorbent was then used to purify the MP-enriched distillate. A final MP bioproduct with average purity of 87.3–93.1 wt % was achieved. The average efficiency of the chromatography separation step varied between 73.9 and 82.5% depending on the silica particle size used.