Producing, evaluating, and upgrading oils from steam liquefaction of poplar chips

Abstract

Chipped poplar wood can be liquefied using only high temperature/pressure steam (300-355°C). Approximately 60 per cent of the carbon feed appears in the oil phase (acetone-soluble). The oils (ca. 45% mass yield) are just solid at room temperature but soften around 50°C (1.5% moisture). They typically contain 69% carbon, 5.8% hydrogen and about 25% oxygen. Both weight and number-average molecular weights, as measured by HPSEC, are less than 1000. The major fraction of the oil is of lignin origin. Model compound studies show that the major oil functionalities (phenolic OH and OCH3) can be hydrodeoxygenated using typical hydrodesulfurisation catalysts.