Cultivation, Extraction Of Microalgae And Biodiesel Production

Over-use of fossil fuels causes global warming and energy depletion, to explore new and alternative enery has become an urgent worldwide issue. Biofuel that can produce biodiesel includes plant crops, microalgae, animal oil et al, while biodiesel has competitive advantages such as pollution-free, the effect of the greenhouse reducing and so on, therefore, biodiesel has become one of the hot spots in nowadays researches. On the other hand, as one of the raw materials of biomass energy, microalgae has many advantages:high ability to adapt to the environment, simple growth requirements, low needs for nutrition, the direct use of CO2, inorganic salts and organic wastewater; high photosynthetic efficiency, short doubled time, the mass of biomass per unit area is higher plant crops a plenty of times; its farming does not occupy arable land, et al. These advantages indicate that microalgal biomass has the potential to replace fossil fuels. So this thesis is focus on the process study for production of biodiesel from microalgae, the main content is divided into following parts, listed as following:1. Water samples were collected in the Pearl River Delta mangrove areas. With plate separation method more than50strains of algae species were isolated. Screening out of chlorella sp pkuAC166and Monoraphidium sp pkuAC167, which total oil content are18.81%and20.04%respectively. Culture of microalgae in a80L of bioreactor with BG11medium.2. A new mixed extraction method for microalgae was disscussed in this investigation. Through three-component phase diagram for optimizing the ratio of volume, when the ratio of volume is7/2/1for n-propanol/n-hexane/water, which could get highest extraction yield. Employment of extraction methods that related to in the literature for microalgal extraction, the result indicated that the new extraction method is the best. The new extraction methods used for chlorella sp (Shandong Binzhou Tianjian Biotechnology Company), Chlorella sp pkuAC166and Monoraphidium sp pkuAC167, the contain of neutral lipids are6.64%,6.62%and5.38%respectivly. 3. Extraction and convertion for biodiesel production in conventional process together into one-step, directly biodiesel production from microalgae. Through the datas of orthogonal experiments and response surface experiments for optimizing process conditons that included the mass ratio of methanol to dried algae, the catalyst content, reaction temperature, reaction time, speed. With optimized conditions of process to convert into biodiesel, analyze the difference of the biodiesel component with GC-MS in respective, and evaluate the quality.