【摘要】：化石能源日益的枯竭以及生態(tài)環(huán)境的惡化,尋求清潔可再生能源受到廣泛關(guān)注。目前針對生物質(zhì)的利用成為研究熱點,在不同種類生物質(zhì)資源被利用的情況下,落葉是還沒有被完全利用的生物質(zhì)資源。本文選用常見的綠化樹木三球懸鈴木落葉為原料,對其光合生物產(chǎn)氫特性進行了研究。首先從酶解工藝出發(fā),在最大限度上提高酶解產(chǎn)糖量、降低酶解成本的基礎(chǔ)上,確定落葉酶解糖化的最佳酶解工藝條件。其次在對落葉進行預處理的工藝上,利用正交實驗優(yōu)化了稀硫酸預處理工藝。再次研究不同酸堿的預處理對落葉光合生物制氫的影響,并利用修正的Gompertz方程對產(chǎn)氫過程進行回歸分析,驗證了以落葉為原料進行光合生物制氫的可行性和預處理的必要性。最后以單位產(chǎn)氫量為依據(jù),研究了光照、溫度、底物濃度、接種量和初始p H對三球懸鈴木落葉同步糖化產(chǎn)氫的影響,利用Plackett-Burman實驗對以上五個因素進行篩選,篩選出對三球懸鈴木落葉同步糖化生物制氫影響顯著的因素,然后利用響應面法對其進行優(yōu)化實驗,對實驗結(jié)果進行直觀分析與方差分析,以獲取最佳產(chǎn)氫工藝條件。實驗結(jié)果表明,(1)通過對三球懸鈴木落葉的主要成分測定,纖維素、半纖維素和木質(zhì)素含量分別為32.51%、19.65%和30.13%,這和農(nóng)作物秸稈生物質(zhì)相比差別小于10%,說明三球懸鈴木落葉可以作為產(chǎn)氫原料。(2)高效酶解預處理不僅能提高產(chǎn)氫效率、也能降低產(chǎn)氫成本,通過對酶解時間、酶負荷和底物濃度單因素分析,得出最佳酶解條件:酶負荷為150mg/g落葉、酶解反應時間為9h、底物濃度為250mg/m L。(3)通過Plackett-Burman實驗的篩選,得出溫度、初始p H和接種量三個因素對落葉同步糖化產(chǎn)氫影響比較顯著,利用響應面對這三個因素進行優(yōu)化實驗,并對實驗結(jié)果進行方差分析得出同步糖化產(chǎn)氫的最佳工藝:p H為6.30、溫度為35.71℃、接種量為26.63%、產(chǎn)氫量為58.65m L/g,實驗結(jié)果和方程擬合預測值(59.17m L/g)基本吻合。(4)在以落葉為原料進行光合生物產(chǎn)氫過程中,產(chǎn)氫發(fā)酵液里的小分子酸隨著產(chǎn)氫的進行也在不斷地變化,在產(chǎn)氫底物為5g的情況下,光合產(chǎn)氫的發(fā)酵液里累積得到的小分子酸為:乙酸、丁酸、丙酸以及乙醇的濃度分別為624mg/L、422mg/L、558mg/L和866mg/L;暗發(fā)酵產(chǎn)氫末端液相中乙酸、丁酸、丙酸以及乙醇的濃度分別為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，

本文編號：2477392