A new study shows that biofuels made from algae can reduce life cycle carbon dioxide (CO2) emissions by 50 to 70 percent compared to petroleum fuels. And according to the Algae Biomass Organization, citing the study in the journal Bioresource Technology, algae biofuels are approaching the Energy Return on Investment (EROI) values that conventional petroleum has.

“This study affirms that algae-based fuels provide results without compromise,” said Mary Rosenthal, ABO’s executive director. “With significant emissions reductions, a positive energy balance, nutrient recycling and CO2 reuse, algae-based fuels will be a long-term, sustainable source of fuels for our nation.”

The study, “Pilot-scale data provide enhanced estimates of the life cycle energy and emissions profile of algae biofuels produced via hydrothermal liquefaction (HTL),” is a life cycle analysis of an algae cultivation and fuel production process currently employed at pre-commercial scales. The authors examined field data from two facilities operated by Sapphire Energy in Las Cruces and Columbus, New Mexico that grow and process algae into Green Crude oil. Sapphire Energy’s Green Crude can be refined into drop-in fuels such as gasoline, diesel and jet fuel.

The study found that when produced at commercial scales, algae technologies can be expected to be better than first generation biofuels when considering greenhouse emissions and on par with the return on energy investment when compared to those first generation biofuels. This is the first study to analyze real-world data from an existing algae-to-energy demonstration scale farm.

“These real-world data from demonstration scale facilities gave us new insight and allowed us to understand how scale will impact the benefits and costs of algae-to-energy deployment.” said lead author Andres F. Clarens, Assistant Professor of Civil and Environmental Engineering at the University of Virginia, Charlottesville. “These results suggest that algae-based fuels made using HTL have an environmental profile that is comparable to conventional biofuels.”