Effects of pretreatment on liquefaction of pine sawdust and chemical components of product

Pine sawdust was liquefied using methanol-water mixed solvent as liquid agent. The effects of the pretreatment conditions on structural changes of the surface and the liquefaction conversion rate were investigated. The effects of reaction temperature and residence time on sawdust liquefaction were studied, too. The results indicated that different pretreatment can change the sawdust structure. The sawdust pretreated by NaOH had the most structural change. This could broaden the chemical reactivity. The conversion of sawdust was 92.4% after pretreatment of sodium hydroxide solution at 320°C for 10 min. GC-MS analysis showed that the liquid products mainly included alcohols, aldehydes, ketones, acids, esters and phenols. It was also found that pretreatment had an important effect on their contents which reached 40.588%. The major component of liquid product produced with sawdust was aldehyde compounds and urea yields acid compounds. Their contents were 30.878% and 25.311%, respectively. The sawdust pretreated by NaOH trends to formate of ketone compounds, while sawdust pretreated by mixed NaOH and urea yields about 38.478% phenolic compounds.