Quantitative formation of furfural from xylose

Abstract

A study has been made of various methods of distillation of solutions of furfural and of xylose with the object of increasing the 88-percent yield of furfural obtained from xylose by the present standard m ethod of distillation. Sources of error that have been considered are: Decomposition of furfural, volatilization of furfural, effect of rubber stoppers used in the distillation procedure, incompleteness of distillation, furfural formed from hexuronic acid, and substances other than furfural or methylfurfural in the di stillate. A procedure has been developed which prevents superheating of the solution but which gives rapid formation and removal of the furfural. The apparatus has only glass in contact with the hot vapors and acid, and is closed with a trap to prevent evaporation from the di stillate. The procedure employs 12-percent hydrochloric acid saturated with sodium chloride to accelerate the formation of furfural, which is then remo ved by stearn distillation. This prevents decomposition of the furfural and gives a practically theoretical yield of furfural from xylose.