| Budget Amount *help |
¥4,700,000 (Direct Cost: ¥4,700,000)
Fiscal Year 2005: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 2004: ¥3,800,000 (Direct Cost: ¥3,800,000)
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| Research Abstract |
In spite of the importance of tarry material production during heating up period in supercritical water gasification and hydrothermal pretreatment of biomass, the reaction mechanism is not sufficiently understood. In this study, glucose was selected as a model compound, reaction was made to proceed in tubular reactors under hydrothermal conditions, and yield of product compounds including fructose, erythrose, glyceraldehyde, anhydroglucose, and 5-hydorxymethylfurfuraol were determined for specific temperature and reaction time. Referring previous literatures, reaction network was determined, and Arrhenius parameters of each reaction were determined by the least-square method. As a result, reaction order for glucose decomposition was found to change with temperature, indicating main reaction paths to change with hydrothermal reaction field. With these reaction rate parameters, yield of products for different heating rate was calculated. For a lower heating rate, the yield of 5-hydroxymethylfurfural increased. Experimental runs were conducted where heating rate was changed, and it was found that when heating rate is lower, the higher was the yield of tarry material. Analysis of water-soluble products indicated that polymerization of a compound whose molecular weight was around 120 was taking place. In previous studies of heating sugars, 5-hydroxymethylfurfural, whose molecular weight is 126, has been nominated as a cause of colored product, and consideration with the result of this study, it is strongly suggested that 5-hydroxymethylfurfural polymerization contributes to the production of tarry materials.
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