Preparation of 5-hydroxymethylfurfural by hydrothermal treatment of palm kernel shell residues

Abstract

Hydrothermal treatment of biomass is one of the most promising technologies for converting biomass into a higher value-added form. In the past decade, it is well recognized that palm oil production is one of the major industries in Thailand, which generates many residues of palm kernel shell. This work focuses on utilizing hydrothermal treatment of cellulose in palm kernel shell residues for 5-hydroxymethyl-furfural (5-HMF) production. Because the palm kernel shell residues mainly contain cellulose of 60 wt%, it would possibly provide a high yield of sugar products. Palm kernel shells residues were treated by alkali solutions before adding into a batch-type tubular reactor. A series of systematic experiments were performed in a reaction temperature range of 200 to 300 ^oC, heating rate ranging from 5 to 10 ^oC/min, concentration of palm kernel shell residues (feedstock) at 10 and 20 wt%, and lignin content in a range of 3-10%. Moreover, effect of adding of 2-butanol as extracting solvent was also investigated in order to increase the 5-HMF yield in liquid product. It was found that the 5-HMF yield was dependent on the reaction temperature, heating rate, concentration of feedstock and lignin content. Furthermore, the experimental results showed that 2-butanol was a good selective solvents for the production of 5-HMF in the hydrothermal treatment process. In addition, liquid product obtained from the hydrothermal treatment consisted of 1,3-dihydroxyacetone dimer, formic acid, acetaldehyde, acetic acid and furfural.