Effect of Liquefying Agents Mixed with Lower Alcohols and Reaction Temperature on the Microwave Driven Liquefaction of Wood

Abstract

Southern pine (Pinus sp.) is liquefied by microwave heating and PEG/lower alcohols mixtures in the presence of phosphoric acid as the catalyst at 125°C or 150°C. The reaction time is of 15 min, and the liquefaction solvent to wood ratio is of 2:1. The different reaction temperatures used in the present paper did not have obvious influences on liquefaction yield, but have important effects on hydroxyl value. The mixture of lower alcohols such as ethanol and glycerine with PEG had a strong effect on the liquefaction process. The highest liquefaction yield was obtained in liquefying solvents mixed 30% of ethanol and 10% of glycerine with 60% of PEG at 150°C, and the maximum hydroxyl value was gained by PEG (60%) and ethanol (40%) at 150 °C.