三球悬铃木落叶生物质制氢工艺试验研究
发布时间：2019-05-15 09:10
【摘要】：化石能源日益的枯竭以及生态环境的恶化,寻求清洁可再生能源受到广泛关注。目前针对生物质的利用成为研究热点,在不同种类生物质资源被利用的情况下,落叶是还没有被完全利用的生物质资源。本文选用常见的绿化树木三球悬铃木落叶为原料,对其光合生物产氢特性进行了研究。首先从酶解工艺出发,在最大限度上提高酶解产糖量、降低酶解成本的基础上,确定落叶酶解糖化的最佳酶解工艺条件。其次在对落叶进行预处理的工艺上,利用正交实验优化了稀硫酸预处理工艺。再次研究不同酸碱的预处理对落叶光合生物制氢的影响,并利用修正的Gompertz方程对产氢过程进行回归分析,验证了以落叶为原料进行光合生物制氢的可行性和预处理的必要性。最后以单位产氢量为依据,研究了光照、温度、底物浓度、接种量和初始p H对三球悬铃木落叶同步糖化产氢的影响,利用Plackett-Burman实验对以上五个因素进行筛选,筛选出对三球悬铃木落叶同步糖化生物制氢影响显著的因素,然后利用响应面法对其进行优化实验,对实验结果进行直观分析与方差分析,以获取最佳产氢工艺条件。实验结果表明,(1)通过对三球悬铃木落叶的主要成分测定,纤维素、半纤维素和木质素含量分别为32.51%、19.65%和30.13%,这和农作物秸秆生物质相比差别小于10%,说明三球悬铃木落叶可以作为产氢原料。(2)高效酶解预处理不仅能提高产氢效率、也能降低产氢成本,通过对酶解时间、酶负荷和底物浓度单因素分析,得出最佳酶解条件:酶负荷为150mg/g落叶、酶解反应时间为9h、底物浓度为250mg/m L。(3)通过Plackett-Burman实验的筛选,得出温度、初始p H和接种量三个因素对落叶同步糖化产氢影响比较显著,利用响应面对这三个因素进行优化实验,并对实验结果进行方差分析得出同步糖化产氢的最佳工艺:p H为6.30、温度为35.71℃、接种量为26.63%、产氢量为58.65m L/g,实验结果和方程拟合预测值(59.17m L/g)基本吻合。(4)在以落叶为原料进行光合生物产氢过程中,产氢发酵液里的小分子酸随着产氢的进行也在不断地变化,在产氢底物为5g的情况下,光合产氢的发酵液里累积得到的小分子酸为:乙酸、丁酸、丙酸以及乙醇的浓度分别为624mg/L、422mg/L、558mg/L和866mg/L;暗发酵产氢末端液相中乙酸、丁酸、丙酸以及乙醇的浓度分别为2966mg/L、1624mg/L、1365mg/L、1352mg/L。
[Abstract]:With the increasing depletion of fossil energy and the deterioration of ecological environment, the search for clean and renewable energy has been widely concerned. At present, the utilization of biomass has become a research focus. Under the condition that different kinds of biomass resources are utilized, deciduous is a biomass resource that has not yet been fully utilized. In this paper, the hydrogen production characteristics of photosynthetic organisms were studied by using the deciduous leaves of common greening trees as raw materials. Firstly, based on the enzymatic hydrolysis process, the optimum conditions of saccharification of deciduous leaves were determined on the basis of increasing the sugar yield of enzyme hydrolysis to the maximum extent and reducing the cost of enzyme hydrolysis. Secondly, in the pretreatment process of deciduous leaves, the dilute sulfuric acid pretreatment process was optimized by orthogonal experiment. Thirdly, the effects of pretreatment with different acids and bases on hydrogen production by photosynthetic organisms from deciduous leaves were studied, and the modified Gompertz equation was used to analyze the hydrogen production process. The feasibility of hydrogen production from deciduous leaves and the necessity of pretreatment were verified. Finally, based on the unit hydrogen production, the effects of light, temperature, substrate concentration, inoculum size and initial pH on the simultaneous saccharification of leaves of Platycladus armigera were studied. The above five factors were screened by Plackett-Burman experiment. The factors affecting the simultaneous saccharification of the leaves of Platycladus armigera were screened out, and then the response surface method was used to optimize the experiment, and the experimental results were analyzed intuitively and analyzed by variance analysis in order to obtain the optimum hydrogen production conditions. The results showed that: (1) the contents of cellulose, hemicellulose and lignin were 31.51%, 19.65% and 30.13%, respectively. Compared with crop straw biomass, the difference is less than 10%, which indicates that the deciduous leaves of Platycladus armigera can be used as hydrogen producing raw materials. (2) High efficiency enzyme hydrolysis pretreatment can not only improve the hydrogen production efficiency, but also reduce the hydrogen production cost. The optimum conditions of enzyme hydrolysis were obtained by single factor analysis of enzyme load and substrate concentration. The optimum conditions of enzyme hydrolysis were as follows: the enzyme load was 150mg/g deciduous, the reaction time was 9 h, and the substrate concentration was 250mg/m L. (3) the temperature was obtained by Plackett-Burman experiment. The effects of initial pH and inoculum size on hydrogen production by simultaneous saccharification of deciduous leaves were significant. The results of variance analysis showed that the optimum process of simultaneous saccharification was 6.30, the temperature was 35.71 鈩，
本文编号：2477392
[Abstract]:With the increasing depletion of fossil energy and the deterioration of ecological environment, the search for clean and renewable energy has been widely concerned. At present, the utilization of biomass has become a research focus. Under the condition that different kinds of biomass resources are utilized, deciduous is a biomass resource that has not yet been fully utilized. In this paper, the hydrogen production characteristics of photosynthetic organisms were studied by using the deciduous leaves of common greening trees as raw materials. Firstly, based on the enzymatic hydrolysis process, the optimum conditions of saccharification of deciduous leaves were determined on the basis of increasing the sugar yield of enzyme hydrolysis to the maximum extent and reducing the cost of enzyme hydrolysis. Secondly, in the pretreatment process of deciduous leaves, the dilute sulfuric acid pretreatment process was optimized by orthogonal experiment. Thirdly, the effects of pretreatment with different acids and bases on hydrogen production by photosynthetic organisms from deciduous leaves were studied, and the modified Gompertz equation was used to analyze the hydrogen production process. The feasibility of hydrogen production from deciduous leaves and the necessity of pretreatment were verified. Finally, based on the unit hydrogen production, the effects of light, temperature, substrate concentration, inoculum size and initial pH on the simultaneous saccharification of leaves of Platycladus armigera were studied. The above five factors were screened by Plackett-Burman experiment. The factors affecting the simultaneous saccharification of the leaves of Platycladus armigera were screened out, and then the response surface method was used to optimize the experiment, and the experimental results were analyzed intuitively and analyzed by variance analysis in order to obtain the optimum hydrogen production conditions. The results showed that: (1) the contents of cellulose, hemicellulose and lignin were 31.51%, 19.65% and 30.13%, respectively. Compared with crop straw biomass, the difference is less than 10%, which indicates that the deciduous leaves of Platycladus armigera can be used as hydrogen producing raw materials. (2) High efficiency enzyme hydrolysis pretreatment can not only improve the hydrogen production efficiency, but also reduce the hydrogen production cost. The optimum conditions of enzyme hydrolysis were obtained by single factor analysis of enzyme load and substrate concentration. The optimum conditions of enzyme hydrolysis were as follows: the enzyme load was 150mg/g deciduous, the reaction time was 9 h, and the substrate concentration was 250mg/m L. (3) the temperature was obtained by Plackett-Burman experiment. The effects of initial pH and inoculum size on hydrogen production by simultaneous saccharification of deciduous leaves were significant. The results of variance analysis showed that the optimum process of simultaneous saccharification was 6.30, the temperature was 35.71 鈩，
本文编号：2477392
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