Preparation and Property Measurement of Liquid Fuel from Supercritical Ethanolysis of Wheat Stalk^†

Abstract

Optimum conditions for preparing liquid fuel (LF) by supercritical ethanolysis (SCE) of wheat stalk powder (WSP) were determined by orthogonal experiment. Fuel properties, including pH, density, viscosity, flash and ignition temperatures, heating value, water content, and distillation range, of the LF obtained under the optimum conditions were measured. Subsequent treatments, including dehydration and distillation, were conducted upon the LF. The LFs before and after the treatments were analyzed with gas chromatography/mass spectrometry (GC/MS). SCE of model substances cellulose and lignin was also examined for understanding the formation pathways of typical organic compounds in the LF. The results show that the optimum conditions for preparing LF are 300 °C (reaction temperature), 10 min (reaction time), and 1:24 (WSP/ethanol ratio). After treatments, fuel properties of the LF are eligible for practical use. The main components in the LF include shorter chain carboxylic acids and their ethyl esters, furan derivatives, cyclopentanones, phenol derivatives, benzene derivatives, aromatic acid derivatives, longer chain carboxylic ethyl esters, and sterides.