Virginia Engineers Say Algae-based Biofuel Has Bigger Footprint

Researchers from the University of Virginia's Department of Civil and Environmental Engineering have found there are significant environmental hurdles to overcome before fuel production using algae-based biofuels ramps up. They propose using wastewater as a solution to some of these challenges.

The Research, just published in the journal Environmental Science & Technology, demonstrates that algae production consumes more energy, has higher greenhouse gas emissions, and uses more water than other biofuel sources, such as switchgrass, canola, and corn.

"Given what we know about algae production pilot projects over the past 10 to 15 years, we've found that algae's environmental footprint is larger than other terrestrial crops," said Andres Clarens, an assistant professor and lead author on the paper.

Clarens collaborated on the paper with Lisa M. Colosi, also an assistant professor in the department; Eleazar P. Resurreccion, a graduate student in the department; and Mark A. White, a professor in U.Va.'s McIntire School of Commerce.

As an environmentally sustainable alternative to current algae production methods, the researchers propose situating algae production ponds behind wastewater treatment facilities to capture phosphorous and nitrogen – essential nutrients for growing algae that would otherwise need to be produced from petroleum. Those same nutrients are discharged to local waterways, damaging the Chesapeake Bay and other waterbodies, and current technology to remove them is prohibitively expensive.

While the researchers found algae production to have a greater environmental impact than other sources, it remains an attractive source for energy. Algae, which are grown in water, don't compete with food crops grown on land and also tend to have higher energy yields than sources such as corn or switchgrass. Additionally, algae's high lipid content makes for efficient refinement to liquid fuels that could be used to power vehicles, according to the research.

"Before we make major investments in algae production, we should really know the environmental impact of this technology," Clarens said. "If we do decide to move forward with algae as a fuel source, it's important we understand the ways we can produce it with the least impact, and that's where combining production with wastewater treatment operations comes in."

The research group's plans include conducting demonstration projects for the wastewater production methods. They are also pursuing complementary research on the economic lifecycle of algae compared to other bionenergy feedstocks.

The Algal Biomass Organization (ABO), the trade association for the algae industry, challenged the conclusions of the published report claiming that conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions, and water. ABO says the report was based on obsolete data and grossly outdated business models and overlooked tremendous improvements in technology and processes across the production cycle. ABO believes strongly that these obsolete data and faulty assumptions seriously undermine the credibility of the study’s conclusions.

“We appreciate and support the interest in algae among the scientific community, and agree that examination of the life cycle impacts of algae for fuel processes is important,” said Mary Rosenthal, executive director of ABO. “However, we expect such research to be based on current information, valid assumptions, and proven facts. Unfortunately, this report falls short of those standards with its use of decades-old data and errant scientists.

ABO is a non-profit organization whose mission is to promote the development of viable commercial markets for renewable and sustainable commodities derived from algae. Its membership is comprised of people, companies and organizations across the value chain.

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