Algae plus swine waste could equal biofuel

11 June 2024 09:09

Center for Green Economy

Yunlin - Mixing algae and pig runoff produces a chemical reaction that creates biofuels, according to Taiwanese and other researchers. Finding that they could convert more than 29 percent of algae and wastewater into biocrude oil, the researchers could create a circular economy to reduce carbon emissions that cause climate change.

Wastewater from pig farms is a toxic substance that can taint groundwater. Algae is a plentiful substance that thrives under the right circumstances. Now Taiwanese and other researchers believe the two materials can help create renewable biofuels that might replace oil and gas.

Published in the Biochemical Engineering Journal on June 9, the article entitled “Hydrothermal liquefaction of swine wastewater-cultivated Chlorella sorokiniana SU-1 biomass for sustainable biofuel production” explains how microscopic freshwater green algae will convert swine wastewater into biocrude oil.

The article’s co-authors are based at the National Yunlin University of Science and Technology and the Tunghai University in Taiwan as well as Sunway University in Malaysia. 

“Excessive reliance on nonrenewable energy sources to meet the rising energy consumption of a growing population is one of the world's most pressing concerns today,” they wrote. “One of the key advantages of cultivating microalgae is their ability to utilize wastewater as a growth medium, thereby contributing to the treatment and valorization of waste streams.”

Swine wastewater is loaded with nutrients like nitrogen and phosphorous that algae can consume. The biomass that results is an ideal substance for conversion into biocrude oil through hydrothermal liquefaction, a chemical reaction involving high temperatures and high pressure.

The researchers examined the dilution rations for swine wastewater, the number of microalgae, carbon concentrations, and the intensity of temperatures and light to determine the ideal conditions for biocrude oil production. ce/jd