农业废弃物水热糖化的实验研究

Saccharification of Agricultural Wastes Under Hydrothermal Reaction Conditions

在亚临界水的状态下对稻壳和麦麸进行水热糖化实验,考察了反应温度、反应时间、加入水的体积以及氧化剂、醋酸、乙醇、碳酸钠等对还原糖产率的影响。结果表明,稻壳和麦麸的还原糖产率随着温度、时间、水的体积的变化都存在一个先增加后减少的趋势;还原糖产率随H2O2和Na2CO3浓度的升高而下降;乙醇的增加有利于还原糖产率的提高,在乙醇的浓度为70%时还原糖产率达到最高,稻壳为47.5%,麦麸为63%;而醋酸对还原糖产率的影响比较小。

The saccharification of rice hull and wheat bran under the conditions of sub-critical water was carried out in batch reactors with the reaction temperature 250～374 ℃, reaction time 0.5～5 min and water volume 2～5 mL. The effect of reaction temperature, time, water volume, oxidant, acetic acid, ethanol, and sodium carbonate on the yield （Y%） of reducing sugar were investigated. The results indicated that the yield of reducing sugar all increased at first and then declined with the increasing temperature, time and water volume. At 300 ℃-350 ℃, 4 min, and water volume of 4 mL, the yield of reducing glucose reached the maximum, respectively. Hydrogen peroxide and sodium carbonate could accelerate the degradation of reducing sugar and the yield of reducing sugar decreased with increasing hydrogen peroxide and sodium carbonate, while adding ethanol could increase the yield of reducing sugar which increased with increasing concentration of ethanol. When the concentration of ethanol was 70%, the yield of reducing sugar reached the maximum, being 47.5% and 63% for the rice hull and the wheat bran respectively. Furthermore, the yield of reducing sugar varied little when adding acetic acid, which showed that the influence of acetic acid was relatively weak.