【作者】 张杰；

【导师】 胡晓萍；

【作者基本信息】 浙江大学 ， 化学工程， 2010， 硕士

【摘要】 在全球都在推行低碳经济的今天,研究可再生、二氧化碳排放量少的新能源对于环境保护以及经济可持续发展有着重要意义。以植物油为原料进行生物柴油生产的工艺存在占耕地面积大的问题,使得生物柴油的大规模工业化生产难以持续进行。而以微藻为原料生产生物柴油的工艺能够解决这个问题,而且微藻产油效率高于油植物。本课题以反应工程学理论为基础,建立新的微藻培养器,并对微藻工厂化培养进行了探究,主要进行了以下工作:1.获得含油量高的金藻,以人工海水为培养液,led灯为光源,在5L玻璃间歇釜中考察了不同温度,光源强度和光暗频率以及通CO₂对金藻生长速率的影响。结果表明:培养时通CO₂,不仅能提高培养液中反应物CO₂的浓度,也能减少产物O₂浓度,有利于微藻的生长;金藻生长最适温度为25℃;最适光强为180001ux;大于10hz的频闪光源能明显减弱光抑制作用,促进微藻生长,最适频率为20hz,生长速率比相同光强下连续光高18.6%。得到了适合金藻的生长条件。2.气相色谱法测定了金藻生物柴油主要含棕榈酸甲酯、硬脂酸甲酯、油酸甲酯、亚油酸甲酯、亚麻酸甲酯,含量分别为39.9%、2.38%、28.9%、18.25%、4.46%。碳链长度在16-18,能够作为生产生物柴油的原料。3.设计并建立了一套内径为5CM内置光源管式振荡流反应器,用以金藻的培养。该反应装置由振动部分产生不同频率和振幅的正弦振动,并将振动传递到流动部分腔室中的流体。在Re₀=818,St=3.98振荡优化条件下的培养结果表明:浓度很小时（OD＜0.2）,虽然增长比很大,但是增长的绝对量太少;浓度很大时（OD＞0.7）,由于营养物质相对浓度变小以及有害的代谢产物量多,细胞生长受到限制,不仅增长比小,而且增长的绝对量也小。而金藻浓度在0.2和0.7之间时,其增长量最大。因此在用该新型反应器培养金藻时,浓度控制在0.2～0.7内收益率最高。4.在相同停留时间和初始浓度下,对金藻在光催化管式振荡流反应器与球形间歇釜中培养结果进行比较。结果为:（1）.浓度较低时,金藻在前者与后者中的增长量之比随着浓度的增大而增大,从低浓度时的1.4倍随着初始浓度的增加到最高的1.78倍。此时光源利用率为影响金藻生长的主要因素,而前者的光源利用率明显好于后者,并且随着浓度的增大而增大;（2）.当浓度比较高（OD值＞0.6）时,增长量之比有所减少,从最高的1.78倍下降到1.5倍,此时金藻生长的主要限制因素为其高浓度带来的生长环境恶化,光利用率为次要因素。以上结果表明:管式振荡流光催化反应器流体的流动特性使其培养微藻的效果明显要好于搅拌间歇釜反应器。而该新型反应器工业放大只需串联上管子,相对简易,不影响培养效率,又能连续化生产。搅拌间歇釜放大之后的光利用率将会更低,降低培养速度,而且只能间歇生产。因此当进行大规模培养微藻时,新型光催化管式振荡流反应器将比搅拌间歇釜更有优势。更多还原

【Abstract】 Today,the whole world are in the pursuit of low-carbon economy,it is urgent to develop a new renewable,economic energy for environmental protection and sustainable economic development.However,there still exist some bottlenecks for the production of biodiesel,such as large area occupied when using vegetable oil as raw material,which making large-scale industrial production of bio-diesel hard to continue.In this background,scientists came up with a new idea to resolve similar problem with traditional method:the microalgae bio-diesel.This paper will design a new microalgae-based incubator on the basis of the theory for reaction engineering,We has taken some endeavor as below:1.The Chrysophyta with high oil content has been obtained.It is cultured in 5 liter plastic batch reactor,with artificial sea water as nutrient solution and LED-light as light source.Different factors have been studied,such as temperature,intensity of light source,light strength frequency and the flow of CO₂ Experiment results show that:The flow of CO₂ can not only improve the concentration of CO₂ as reactant,but also decrease the concentration of O₂,which will help the growth of the algae.The optional cultural temperature is 25℃,the optimal intensity of light is 180001ux.The strobe frequency more than 10hz is capable of reducing photoinhibition effect,and the growth rate would quickened 18.6%more than the condition of continuous illumination with identical light strength.2.Gas chromatography has been introduced to determine the composition of the biodiesel produced by golden algae.The carbon chain length is mainly between 16 to 18,with the element of methyl palmitate（39.9%）,methyl stearate（2.38%）,methyl oleate（28.9%）,methyl linoleate（18.25%） and methyl linolenate（4.46%）.These data indicate the potential to use golden algae as biodiesel source.3.A set of Photocatalysis OFR has been designed and established to algae culturing.The reaction device produced by the vibrating part of the different frequency and amplitude of the sinusoidal vibration transmission to the mobile part of the chamber in the fluid.Under Re₀ = 818,St = 3.98 optimized conditions of oscillation,culture results showed that:the concentration is very low（OD＜0.2）, although the growth than large,but little increase in absolute amount;concentration is very large（OD＞0.7）,As the relative concentration of nutrients as well as the bigger quantity of harmful metabolites,cell growth is limited,both growth than and growing volume are small.The golden algae get the largest growth when concentration is between 0.2 and 0.7.Therefore,in using this new reactor train golden algae,the concentration at 0.2 to 0.7 is in the highest rate of return.These above results demonstrated that using OFR,the flow characteristics is evidently better than batch reactor with stirred tank.The industrial scale-up of the new reactor can be applied in continuous production,and has no impact on culturing. Moreover,it is relatively simple to scale-up,for it is only demands combining some tubes.While the batch reactor can only applied in batch process,with lower light use ratio and growth velocity.It came to the conclusion that the new set is much more appropriate for the large-scale algae culturing.更多还原