Effect of Reaction Conditions on Furfural Production

Abstract

Furfural is important in biorefinery concept as a key derivative for the production of non-petroleum-derived chemicals competing with crude oil. Usually furfural has been produced from agricultural materials which are rich in hemicellulose fraction, but other biomass has not been utilized actively for the furfural production. In order to make use of various biomass feedstocks for furfural production, this study investigated the dehydration pattern of various sugars and improvement of furfural production yield by an environment-friendly way. For studying the dehydration patterns of sugars, 23 sugars were tested and among them 18 sugars showed specific dehydration patterns where major dehydration products were 5-hydroxymethyl-2-furancarboxylic acid, 2-furoic acid, reductic acid, furfural, and 5-hydroxymethyl-furfural. Based on the dehydration pattern, xylose, which is one of the most abundant sugars, was selected as a source of furfural production. To obtain furfural from xylose an aqueous solution and ionic liquid ([BMIM][Cl]) were examined as a solvent system. When the reaction was carried out in aqueous system with varying H2SO4 concentration and temperature, a low production yield of furfural was observed. It was assumed that [BMIM][Cl] could stabilize furfural and prevent additional side reactions. As expected, [BMIM][Cl] enhanced furfural production and the highest yield in [BMIM][Cl] was more than twice of that in the aqueous system. Thermal decarboxylation of uronic acid was tested in an effort for expansion of furfural sources. Conversions of mono- and poly-uronic acid to xylose and xylan by decarboxylation at C6 carboxyl group were expected but products were not analyzed certainly. Therefore, additional studies on hydrolysis and analysis method are needed to confirm whether decarboxylation took place or not. If experimental improvements in decarboxylation and hydrolysis conditions are made, this approach is expected to become an efficient way for the production of furfural from uronic acid-containing biomass materials.