能源草光合生物制氢工艺优化实验研究

发布时间：2018-04-20 11:24

本文选题：能源草 + 光合细菌　；参考：《河南农业大学》2015年硕士论文

【摘要】：随着化石能源的枯竭和生态环境的恶化,寻求可替代化石能源的清洁可再生能源成为人们研究的热点。能源草的能源化利用是近年来生物质能源领域的研究热点。本文选用王草、象草、柳枝稷、紫花苜蓿这四种常见的能源草为原料,分别对其光合生物制氢特性进行了实验研究。首先将能源草原料利用纤维素酶酶解预处理,并利用其纤维素酶酶解液作为产氢底物,以四种能源草酶酶解的累积产氢量和产氢速率为考察指标,对比了不同类型能源草的产氢能力,并利用修正的Gompertz方程对产氢过程进行回归分析,验证了能源草作为光合制氢原料的技术可行性。利用其中产氢效果较好的紫花苜蓿为底物,以对产氢影响较为显著的温度、光照强度、以及初始p H三种因素设计了三因素三水平正交实验组,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)通过对王草、象草、柳枝稷和紫花苜蓿等四种能源草的主要成分的测定,王草、象草、柳枝稷和紫花苜蓿的纤维素+半纤维素含量分别为56.19%、54.14%、61.11%和57.13%,这4种能源草的主要成分与常用的光合产氢原料如小麦、玉米、水稻等农作物秸秆的主要成分相差不大,说明这4种能源草均具有较好的能源转化的物质基础。(2)在底物浓度为10g/L,酶负荷为100mg/g能源草,酶解温度为50°C,酶解时间48h时,王草的还原糖浓度为5.14mg/m L,象草为4.04mg/m L,柳枝稷为2.27mg/m L,紫花苜蓿为5.34mg/m L。可见王草和紫花苜蓿这两种能源草经过纤维素酶处理过后的还原糖产量比其他两种的要高一些,其中紫花苜蓿的略高,但是跟王草的相差不大,而象草的还原糖产量比这两种稍低,柳枝稷的还原糖产量最低。(3)当产氢工艺条件为光合细菌接种量30%、温度30°C、光照度2000lux、发酵时间120h时,紫花苜蓿产氢性能最好,王草次之,而象草和柳枝稷的产氢性能较差。王草、象草、柳枝稷和紫花苜蓿的累积产氢量分别为75.3m L、27.2m L、26.1m L、81.6m L,最大产氢速率分别为7.8m L/(h·L),3.5m L/(h·L),4.3m L/(h·L),14.75m L/(h·L)。(4)在所选水平范围内,各因素对能源草产氢的影响主次顺序为温度→光照强度→初始p H值,由方差分析可知,温度和光照强度对能源草光合产氢性能影响为显著,初始p H值为不显著,由各因素水平值的均值可见,能源草光合生物制氢的最佳工艺水平为30°C,p H=7,光照强度为3000lx。(5)利用王草、紫花苜蓿等能源草为原料来进行光合制氢是可行的,将能源草这种绿色生物质资源同光合生物制氢技术结合起来,既能改善生态环境,又能产生清洁的氢能源,具有显著的社会、环境和经济效益。
[Abstract]:With the depletion of fossil energy and the deterioration of ecological environment, the search for clean and renewable energy as a substitute for fossil energy has become a hot topic. In recent years, the energy utilization of energy grass is a hot topic in the field of biomass energy. In this paper, four common energy grasses, Wang grass, elephant grass, switchgrass and alfalfa, were used as raw materials to study the hydrogen production characteristics of photosynthetic organisms. At first, the raw material of energy grass was pretreated by cellulase enzymatic hydrolysis, and its cellulase hydrolysate was used as the substrate of hydrogen production. The cumulative hydrogen production and hydrogen production rate of four kinds of energy grass enzymatic hydrolysis were used as the index of investigation. The hydrogen production capacity of different types of energy grass was compared, and the regression analysis of hydrogen production process was carried out by using the modified Gompertz equation. The technical feasibility of energy grass as a raw material for hydrogen production was verified. Using alfalfa with better hydrogen production effect as substrate, three factors and three levels orthogonal experimental group were designed, which had significant effect on hydrogen production, such as temperature, light intensity and initial pH. Visual analysis and variance analysis of the experimental results were carried out to obtain the best conditions for hydrogen production. The results showed that the main components of four kinds of energy grass, Wang grass, elephant grass, switchgrass and alfalfa, were determined. The contents of cellulose hemicellulose in switchgrass and alfalfa were 56.19% and 54.14%, respectively. The main components of the four energy grasses were similar to those of common photosynthetic hydrogen production materials such as wheat, corn, rice and so on. The results showed that all of them had a good material basis for energy conversion. When the substrate concentration was 10 g / L, the enzyme loading was 100mg/g energy grass, the enzymatic hydrolysis temperature was 50 掳C, and the enzymatic hydrolysis time was 48 h. The concentration of reducing sugar was 5.14mg/m L, 4.04mg/m L, 2.27mg/m L and 5.34mg/m L. It can be seen that the yield of reducing sugar of royal grass and alfalfa after cellulase treatment is higher than that of the other two kinds. The alfalfa yield is slightly higher, but it is not different from that of royal grass. The yield of reducing sugar of elephant grass is lower than that of these two kinds, and the yield of reducing sugar of switchgrass is the lowest.) when the technological conditions of hydrogen production are inoculation amount of photosynthetic bacteria 30 掳C, temperature 30 掳C, luminance 2000c, fermentation time 120 h, the hydrogen production performance of alfalfa is the best, followed by Wang Cao. The hydrogen production of elephant grass and switchgrass was poor. The cumulative hydrogen production of Wang grass, elephant grass, switchgrass and alfalfa were 75.3m L ~ (27.2) L ~ (27. 2) L ~ (-1) ~ 26.1m L ~ (-1) and 81.6 m / L, respectively, and the maximum hydrogen production rate was 7.8m L / m / L ~ (-1) / h ~ 3.5m L ~ (-1) / L ~ + 4.3m L ~ (-1) L / L ~ (14.75 m / L ~ (-1) 路L ~ (-1))). The primary and secondary order of the effects of various factors on hydrogen production of energy grass was the initial pH value of light intensity and temperature. According to the analysis of variance, the effect of temperature and light intensity on photosynthetic hydrogen production of energy grass was significant, but the initial pH value was not significant. It can be seen from the mean value of each factor level that the optimum technology level of photosynthetic biological hydrogen production of energy grass is 30 掳CpH7 and the light intensity is 3000lx.f.5) it is feasible to use the energy grass such as royal grass and alfalfa as raw materials to produce hydrogen by photosynthesis. The combination of green biomass resources such as energy grass and photosynthetic biological hydrogen production technology can not only improve the ecological environment but also produce clean hydrogen energy. It has remarkable social, environmental and economic benefits.
【学位授予单位】：河南农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S216;TQ116.2

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