(567cd) ALKALINE PRE-TREATMENT of Microalgal BIOMASS for Bioethanol PRODUCTION

Danquah, M., Monash University

The increasing demand for energy has lead to the depletion of fossil fuel reserves on a global scale. The Kyoto protocol outlines the need to reduce greenhouse emissions, particulate matter and volatile organic compounds, caused from fossil fuels. This has seen the rise in biofuel globally. Bioethanol is one such biofuel which is derived from renewable biomass such as sugar and starch materials. However, the main problem with most of these materials is that they either compete with the limited agricultural lands needed for food and feed production or do not produce higher ethanol yield for wide scale production. Thus, microalgal biomass are reported to have the potential in solving the problems that faced by the existing fermentation feedstock. Microalgae provide many advantages such as grow rapidly and practically anywhere with or without soil, absorb CO2 and other greenhouse gases during photosynthesis thus reducing the greenhouse gas emissions that released into the atmosphere and can be grown in sea water so there is no need to use fresh water to grow the fuel. To produce bioethanol from microalgal biomass, different steps are required such as pre-treatment, hydrolysis, fermentation and product recovery. This study examines the effect of alkaline pre-treatment (using sodium hydroxide, NaOH) on microalgal biomass for bioethanol production. Three parameters were investigated, the concentration of NaOH, temperature and pre-treatment time. It was found that the highest yield was 0.26gEthanol/gAlgae obtained using 0.75% (w/v) of NaOH under 120ºC for 30min. Thus, alkaline pre-treatment shows a promising method to pre-treat microalgal biomass for bioethanol production.