Optimization of parameters for the cultivation of algae extraction of lipid and its esterification to biodiesel

Abstract

The alternate fuels are in high demand owing to the decline in petroleum supply, dwindling resources in the coal reserves, rampant climate changes, global warming, and other energy security issues. The continuous depletion in the non-renewable natural resources has paved way for the exploration of renewable sources. One important and valuable energy resource which has garnered great interest is the biomass. Several of these biological materials used in the bioethanol production are of feedstock resources. Moreover, ethanol due to its corrosive nature cannot be used in the engines as it is incompatible with the existing engine design. Biodiesel is the fatty acid methyl esters (FAME) derived from vegetable oils and animal fats which has received great attention since 1990s. Biodiesel is biodegradable, renewable and non-toxic fuel. Microalgae are unique and versatile organisms considered as the third generation fuels. They are very well-known for its myriad range of applications such as nutraceutical, cosmetics, biofertilizers etc., The algae are remarkable for its carbon capturing ability by photosynthesis and its biomass can be used for the production of biodiesel whereby the lipid accumulated can be converted to FAME via transesterification process. Few algal species accumulate lipid as high as 40% of the dry weight of the biomass. However, achieving high biomass and lipid content simultaneously has been a great limitation owing higher growth rate of the microalgae. Hence, the present research is focused on developing a novel media for the cultivation of microalgae isolated from freshwater towards the production of high biomass and lipid and to transesterify the lipid to biodiesel. However, the optimization study towards the concurrent production of biomass and lipid was not performed at such high carbon and nitrogen sources.The Waste Cooking Oil (WCO) collected from food outlets has also been used as a source for the production of biodiesel and to study the kinetics of the transesterification process.