Michigan Researchers Turn Wet Algae into Biodiesel

John Davis

Researchers have found a feasible way to turn wet algal biomass directly into biodiesel.

Biodiesel Magazine reports
that University of Michigan scientists have published a paper on a two-step hydrolysis-solvolysis process that eliminates costly biomass drying, organic solvent extraction and catalysts:

In the first step, wet algal biomass contained 80 percent moisture and was 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. In the second step, the wet, fatty acid-rich solids underwent supercritical transesterification with ethanol to produce fatty acid ethyl esters (FAEEs). The team used Chlorella vulgaris algae, which contained 53.3 percent lipid content.

According to Phillip Savage, lead researcher on the project, the team gathered the wet algae grown from the lab and centrifuged it to transform the algal biomass into a paste-like substance. “At large scale that probably wouldn’t be applicable for an economical process,” he noted. “We got something that was probably around 10 to 20 percent solids to the balance of water.”

The research yielded promising results, Savage added, but the project is anticipated to be refined and optimized in order for to demonstrate greater economic and environmental feasibility of the process on a larger scale.

The researchers say more work will need to be done to improve the yields and cut down on inputs.

algae, Biodiesel