辐照处理木质纤维素中发酵抑制物分析及其对乙醇发酵的影响
发布时间：2019-05-26 20:50
【摘要】：预处理是木质纤维素制备燃料乙醇的关键工序之一,因为木质纤维素原料不能直接水解,它需要通过预处理的工序来破坏其物理化学结构,促进其水解。60Coγ辐照是一种高效环保的预处理方法,它能打破木质纤维素结构,促使纤维素酶有效酶解纤维素,提高乙醇转化率。但同时60Coγ辐照会使木质纤维素原料产生一些发酵抑制物。本文建立了高效液相色谱同时检测三类主要抑制物(香草醛、香草酸、对羟基苯甲酸、4-羟基苯甲醛、对香豆酸、丁香酸等苯系化合物、糠醛等呋喃衍生物以及甲酸、乙酸等有机酸)的方法,并对60Coy辐照处理芒草、芦苇及油菜秸秆中的发酵抑制物进行了定量分析,研究了三种木质纤维素原料在0～1200kGy辐照处理后的发酵抑制物含量变化规律,并选用1200kGy辐照的芒草进行Ca(OH)_2过碱化脱毒处理和活性炭吸附脱毒处理,研究脱毒处理对发酵抑制物的脱除效果及其对安琪酵母发酵产乙醇的影响。主要研究结果如下：1、根据上述九种目标发酵抑制物的性质,对液相色谱中检测波长、流动相(种类、pH、缓冲盐)、流速、柱温以及洗脱梯度进行优化,试验结果表明,采用C18色谱柱,柱温25℃,乙腈-0.01mol(NH4)2HPO4(磷酸调节pH至2.7)为流动相,梯度洗脱,流速为0.8mL/min,多波长紫外检测,可实现目标化合物的有效分离和测定。九种目标化合物的线性回归方程相关系数为0.9995-1.0000,加标回收率均在96%以上,相对标准偏差为1.5%-2.3%,最低检出限为0.1-0.89 mg/L,满足定量分析的要求。2、对0～1200kGy辐照处理后的芒草、芦苇和油菜秸秆三种木质纤维素原料水提液进行检测发现,三大类抑制物的含量比例从高到低依次为：有机酸(甲酸、乙酸)、苯系化合物、呋喃衍生物(糠醛)；各发酵抑制物含量随着辐照剂量的增大而增大。其中,辐照处理芦苇中苯系化合物的含量最高,在1200kGy时达149.38mg/L；油菜秸秆中有机酸的总含量最高,在1000kGy时达600mg/L。3、选用1200kGy辐照的芒草进行脱毒处理,结果表明：Ca(OH)_2过碱化脱毒处理可除去部分抑制物,而活性炭吸附法能脱除大部分抑制物,但是活性炭的吸附作用导致可发酵糖的损失也比较大,损失量达30%。将脱毒后的原料与未脱毒的进行对照发酵试验发现,经过发酵24h后,过碱化处理辐照芒草发酵生成的乙醇浓度为3.22g/L,活性炭吸附的辐照芒草发酵生成的乙醇浓度为3.44g/L,而未脱毒的辐照芒草发酵生成的乙醇浓度为3.50g/L。
[Abstract]:Pretreatment is one of the key processes in the preparation of fuel ethanol from lignocellulose, because lignocellulose raw materials can not be hydrolyzed directly, it needs to destroy its physicochemical structure through the pretreatment process. 60Co gamma irradiation is an efficient and environmentally friendly pretreatment method, which can break the structure of lignocellulose, promote cellulase to hydrolyze cellulose effectively and increase the conversion of ethanol. But at the same time, 60 Co 纬 irradiation will make lignocellulose raw materials produce some fermentation inhibitors. A high performance liquid chromatography (HPLC) method for the simultaneous determination of three main inhibitors (vanillin, vanillic acid, p-hydroxybenzoic acid, 4-hydroxybenzaldehyde, p-coumaric acid, eugenic acid, furfural and formic acid) was established. The fermentation inhibitors in mango grass, Reed and rape straw treated by 60Coy irradiation were quantitatively analyzed, and the contents of fermentation inhibitors of three lignocellulose raw materials treated with 0~1200kGy irradiation were studied. The 1200kGy irradiated mango grass was used for Ca (OH) _ 2 superalkalination detoxification and activated carbon adsorption detoxification to study the removal effect of detoxification treatment on fermentation inhibitor and its effect on ethanol production by An Qi yeast. The main results are as follows: 1. According to the properties of the above nine target fermentation inhibitors, the detection wavelength, mobile phase (type, pH, buffer salt), flow rate, column temperature and eluting gradient in liquid chromatography were optimized. Using C18 column, column temperature 25 鈩，
本文编号：2485620
[Abstract]:Pretreatment is one of the key processes in the preparation of fuel ethanol from lignocellulose, because lignocellulose raw materials can not be hydrolyzed directly, it needs to destroy its physicochemical structure through the pretreatment process. 60Co gamma irradiation is an efficient and environmentally friendly pretreatment method, which can break the structure of lignocellulose, promote cellulase to hydrolyze cellulose effectively and increase the conversion of ethanol. But at the same time, 60 Co 纬 irradiation will make lignocellulose raw materials produce some fermentation inhibitors. A high performance liquid chromatography (HPLC) method for the simultaneous determination of three main inhibitors (vanillin, vanillic acid, p-hydroxybenzoic acid, 4-hydroxybenzaldehyde, p-coumaric acid, eugenic acid, furfural and formic acid) was established. The fermentation inhibitors in mango grass, Reed and rape straw treated by 60Coy irradiation were quantitatively analyzed, and the contents of fermentation inhibitors of three lignocellulose raw materials treated with 0~1200kGy irradiation were studied. The 1200kGy irradiated mango grass was used for Ca (OH) _ 2 superalkalination detoxification and activated carbon adsorption detoxification to study the removal effect of detoxification treatment on fermentation inhibitor and its effect on ethanol production by An Qi yeast. The main results are as follows: 1. According to the properties of the above nine target fermentation inhibitors, the detection wavelength, mobile phase (type, pH, buffer salt), flow rate, column temperature and eluting gradient in liquid chromatography were optimized. Using C18 column, column temperature 25 鈩，
本文编号：2485620
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