Physical Aspects of the Liquefaction of Poplar Chips By Rapid Aqueous Thermolysis

Abstract

Hybrid poplar chips (6.35 mm square cross section) are converted to a 45–50 per cent mass yield of acetone soluble products when heated fairly rapidly to 330°C in the presence of water. Virtually no char or unconverted wood is produced at 330°C. Water (15%), carbon dioxide (6.4%), aqueous organics (8.5%), and carbon monoxide (0.4%) are also significant products. Element balances for carbon, hydrogen and oxygen are 86, 98 and 96%, respectively, based on total input, or 86, 80 and 75% based on the wood input. Extending the heat-up from 3 minutes to 6 and 9 minutes increases the oil yield, although the molecular weight distribution and chemical compositions of the product may be different. Rate of oil production and the oil yield are increased when less water is present, but this oil chars more readily at higher temperature because liquid water acts as a stabiliser.