The alcoholysis of furfuryl alcohol with different alcohols was carried out by using metal salt catalysts under microwave conditions, achieving high alkyl levulinates’ yields in a short reaction time.

Epoxidation of three fatty acid methyl esters (FAMEs) were carried out with peroxyacid catalysts to investigate the influences of the alkenyl structure on the epoxidation efficiency and selectivity.

Microwave-assisted liquefaction has shown potential for rapid thermal processing of lignocellulosic biomass. The efficiency of microwave heating depends largely on the dielectric properties of the materials being heated. The objective of this study was to investigate the dynamic interactions between microwave energy and the reaction system during the liquefaction of a woody biomass sample. The dielectric properties of poplar wood particles, model compounds representing the three main chemical components of wood, and individual liquefaction solvent components, along with their mixtures, were measured to evaluate their abilities to convert microwave energy to heat at different frequencies. Dry samples of wood particles, cellulose, xylan, and lignin were all poor microwave energy absorbers as indicated by their low dielectric values relative to the liquefaction solvent components and their mixtures; among the two solvents, polyethylene glycol had lower dielectric values than glycerol, likely due to its larger molecular size. Ionic conduction significantly affected the dielectric loss factor of the liquefaction solvent mixture upon the addition of the sulfuric acid catalyst. During the wood liquefaction reactions, temperature was the main factor that governed the dielectric properties through the preheating stage, and then when the system reached 130 °C, the dielectric properties were governed by changes in chemical composition.

Torrefaction is an effective pretreatment method to improve the uniformity and quality of lignocellolosic biomass before further thermal processing (e.g., gasification, combustion). The objective of this study was to determine the impacts of torrefaction as a pretreatment before liquefaction. Wood chips were torrefied for 2 hours at three different temperatures (230, 260, 290 °C) and then subjected to microwave-assisted liquefaction, as was the untreated wood control. The dielectric properties of liquefaction materials, including the biomass samples and liquefaction reagent, were measured to evaluate their abilities to convert electromagnetic energy to heat. The effects of liquefaction time, temperature, and catalyst concentration on the liquefaction efficiency were also investigated. It showed that torrefaction temperature had significant influence on the liquefaction behavior of wood materials. Wood treated at the lowest torrefaction temperature (230 °C) retained the most structural/compositional characteristics of untreated wood and therefore they both exhibited similar liquefaction behaviors. In addition, the higher treatment temperature (290 °C) led to higher liquefaction residue contents, attributed to the increase in carbon content and hydrophobicity from torrefaction.