Chinese researchers develop algae pretreatment doubling biogas production

In China, for more than 60 years, algae have been studied as a potential feedstock for biofuel production, but the cellulose in their cell wall makes it hard to access the critical molecules inside and convert them to biogas. 

In the Journal of Renewable and Sustainable Energy, an international research team reports their success in using urea and sodium hydroxide (NaOH, commonly known as lye or caustic soda) as a pretreatment of algae, which breaks down cellulose and more than doubles biogas production under their initial experimental conditions.

To produce biogas from algae, researchers commonly use a naturally occurring process called anerobic digestion, in which a type of bacteria break down the algae and produce a methane-rich gas mixture that can be purified. The resulting methane can be used in the production of heat, electricity, methanol, car fuel, and other clean energy sources.

This study presents the first steps toward optimizing conditions for such energy production, testing variations in time, temperature, and concentration of lye-urea pretreatment. Specifically, the most effective combination in this study was a 50-minute pretreatment at -16C with a lye-urea concentration of 5.89%.