金属盐助催化下微波辐射秸秆酸解实验研究
金属盐助催化下微波辐射秸秆酸解实验研究
摘 要
我国的农作物纤维素资源十分丰富，仅玉米秸秆约占35%，主要成分为纤维素、半纤维素和木质素，可占到干重的70％。但这些原料大部分都被烧掉，其能量利用率低，只有10%左右。为缓解当前能源危机，寻求农业秸秆的有效利用途径。本实验以玉米秸秆为原料，在微波辐射下进行稀酸水解，以还原糖产率为目标，分别考察了稀硫酸质量分数（1%～5%）、液固比、微波辐射功率、辐射时间、辐射压力等因素对水解的影响。通过实验发现，影响玉米秸秆的主要因素为微波辐射功率和稀酸质量分数，液固比、辐射时间、微波压力对水解影响较小。
研究表明：最佳的水解工艺条件为硫酸质量分数2%，液固比15，微波辐射压力0.4MPa，微波辐射功率225W，微波反应时间40min。在此条件下，玉米秸秆水解还原糖产率为21.96%。本文主要考察了金属盐助催化下微波辐射玉米秸秆酸解的实验的研究，即硫酸锌、硫酸锰、硫酸铜、硫酸亚铁四种金属盐助催化剂对水解效率的影响。其还原糖产率的依次顺序为硫酸亚铁＞硫酸铜＞硫酸锌＞硫酸锰。硫酸亚铁助催化剂加入后，随着硫酸亚铁浓度的增大而逐渐增加，在浓度3%时，还原糖产率达到最大值，37.1%
关键词：玉米秸秆；酸解；水解；纤维素；微波辐射
Experimental Study on Acidolysis of Corn Stover under Microwave Irradiation
Abstract
The resources of our country are very rich in cellulose crops, and the 35% of the cellulose crops is corn stalk, it is composed of cellulose, hemicellulose and lignin, it can account for 70% of dry weight. But most of these materials are burned, the energy utilization is low, only 10%. This experiment takes maize the corn stover as raw material in dilute acid hydrolysis under microwave irradiation to the yield target of reducing sugar, it is investigated dilute sulfuric acid mass fraction (1% ~ 5%), liquid to solid ratio, microwave power, microwave irradiation time, radiation pressure and other factors on the hydrolysis. After the experimental, we found that the main factors affecting corn stalks are microwave radiation power and dilute acid concentration, liquid to solid ratio, microwave radiation time and microwave pressure are less affected on the hydrolysis.
The results show that: the best conditions for hydrolysis is 2% of sulfuric acid concentration, 15 of liquid to solid ratio, microwave radiation pressure is 0.4MPa, microwave power is 225W, 40min of microwave reaction time. Under these conditions, hydrolysis of corn stalk sugar yield reaches 21.96%. This paper mainly studies on acidolysis of corn stover under microwave irradiation, there are four kinds of metal salts effected on the hydrolysis catalyst, including zinc sulfate, manganese sulfate, copper sulfate and ferrous sulfate. The orders of the reducing sugar yield are as follows: ferrous sulfate> sulfate> zinc sulfate> manganese sulfate. After adding ferrous sulfate catalyst, and with the increase of ferrous sulfate, reducing sugar production rate increases gradually, it reaches maximum of 37.1% at the concentration of 3%.
Key words: corn stalk; acid solutions; hydrolysis; cellulose; microwave radiation
*若需了解更多与协助请咨询↓→[电脑QQ][手机QQ]【数据协助】
