Identification of furfural synthesized from pentosan in rice husk

Synthesis of furfural from pentosan in rice husk was carried out in an attempt to produce value-added products from rice husk which is commonly burnt around rice mills of Malaysia. This process involved the conversion of the pentosan fraction in rice husk into pentose, which was then cyclodehydrated to furfural using dilute sulphuric acid. Yield of furfural obtained was 15 g/kg of dry husk. Furfural obtained was characterised using infra-red analysis (IR), gas chromatography (GC) and gas chromatography with mass spectrophotometer (GC-MS). IR spectrum exhibited a very strong absorption at 1,714.46 cm-1, indicating the presence of the conjugated carbonyl (C=O) group. The presence of the aldehyde was proven by two peaks attained at 3,019.55 cm-1 and 2,881.87 cm-1. The product was colourless, but turned yellowish and then dark brown upon exposure to air and light. It had a smell resembling that of bitter almond and its vapour was irritable to skin and eyes. Furfural obtained was in liquid form, with a molecular weight of 96.2 g/mole and the formula of C5H4O2.