July 19, 2019
Feature

The Uncertainties Around Algae for Biofuel

PNNL researchers develop new model for analyzing biocrude yield and economics

Algae being dumped into HTL system

Andrea Starr | Pacific Northwest National Laboratory

Could algae one day replace crude oil as the raw material for what goes into our gas tanks? The answer depends, in large part, on economics.

One method for converting algae to biocrude—a process called hydrothermal liquefaction—is showing promise in laboratories. But uncertainties remain about just how much biocrude the technique might yield, and whether that fuel could compete on price with conventional ones at the pump.

Researchers at PNNL have developed a model that predicts outcomes from the algae HTL process in a way that mirrors commercial reality much more closely than previous analyses.

"Similar studies on algae HTL yields have been done, but they were based on lab benchtop experiments," said Yuan Jiang, a chemical engineer at PNNL and a lead author of the paper. "Those configurations are quite different from a commercial-scale plant."

The researchers found that two factors—algae composition and capital investment—are the biggest drivers of economic uncertainties about the process. In their analysis, algae with more lipids correlated with lower prices.

"Lipid content is key to predicting the yield of biocrude production," Jiang said. The higher the lipids, the analysis found, the higher the yield of biocrude, which can help lower the price. Yet the biocrude price range that emerged from the simulation was still high: between $5 and $16 per gasoline-gallon equivalent due to the uncertainties in algae production cost.

The team’s paper, "Techno-economic uncertainty quantification of algal-derived biocrude via hydrothermal liquefaction," was published in the May 2019 issue of Algal Research. The work was funded by the U.S. Department of Energy’s Bioenergy Technologies Office.

Read more on DOE's website.

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About PNNL

Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science. For more information on PNNL, visit PNNL's News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

Published: July 19, 2019

PNNL Research Team

Yuan Jiang
Susanne B. Jones
Yunhua Zhu
Lesley Snowden-Swan
Andrew J. Schmidt
Justin M. Billing
Daniel Anderson