Wet Extraction of Algal Biomass to Biodiesel.
As you might be aware that extraction of algal biomass directly i.e. avoiding the steps such as dewatering and drying which are energy intensive will help a great deal in reducing the cost of biodiesel obtained from algae.The researchers at the University of Michigan have published the feasibility of a two-step process to produce biodiesel directly from wet algal biomass. The strain which they have used to test this process is Chlorella vulgaris.
Their process is as follows:
First Step – The wet algal biomass is reacted with subcritical water to hydrolyze intracellular lipids, conglomerate cells into an easily filterable solid that retained the lipids and produced a sterile, nutrient-rich aqueous phase.
Second Step – In the second step, the wet, fatty acid-rich solids underwent supercritical transesterification with ethanol to produce fatty acid ethyl esters (FAEEs).
This method is not economically feasible yet – the lead researcher exclaims! the team actually gathered the wet algae grown from the lab and centrifuged it to transform the algal biomass into a paste-like substance.
Research is underway to determine how whole cells, processed algal biomass and intracellular constituents influence transesterification and potentially contribute to nonester components in the final fuel product.
They are also planning to work on the process optimisation so as to reduce the process inputs such as ethanol and thus make the method more economically friendly.The project is also anticipated to be refined and optimized in order for to demonstrate greater economic feasibility of the process on a larger scale.
