Reaction Engineering Research Of Microalgae Culture

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.