Production of Woody Biomass Fuel Using Hydrothermal Treatment and Reduction of Cr(VI) by the Liquid Product

Abstract

In hydrothermal treatment Cryptomeria Japonica (gymnosperm) was treated at temperatures of 270-330 °C in the presence of liquid water for 30 minutes using an autoclave of 10 L capacity. The solid product having heating values of 7,000-7,200 kcal / kg (dry basis) was obtained at yields of 48-55 %. The FT-IR, proximate and ultimate analysis results of this solid product were similar to those of the solid product obtained by hydrothermal treatment of Acacia Mangium (dicotyledonous angiosperm) reported in our previous paper. The liquid product is composed of mainly methyl alcohol, acetic acid, phenolic compounds such as catechol and guaiacol. It doesn't have 2,6dimethoxyphenol which is in the liquid product obtained by hydrothermal treatment of Acacia Mangium.The liquid product from hydrothermal treatment of Cryptomeria Japonica and Acacia Mangium were studied for their ability to reduce Cr(VI) to Cr(III) under pH2 and time exposures of 15 minutes. These results showed that the liquid products have the ability for the reduction of Cr(VI) to Cr(III) because of its components such as catechol and 2-methoxy-4-methyl-phenol which are essentially the phenols with electron-donating substituents. The reduced Cr(III) was removed by precipitation from the solution using CaO or Ca(OH) 2 .