Various combinations of algal species were grown in 80 cattle tanks at the University of Michigan's E.S. George Reserve near Pinckney. Photo provided l Daryl Marshke/Michigan Photography.

ANN ARBOR, MI - It became clear to Bradley Cardinale during his research that the key to creating a successful biofuel from algae is working with Mother Nature, rather than fighting against her.

It is the hope of Cardinale and other researchers at UM to do just that in converting algae into a sustainable biofuel from feedstocks in outdoor ponds into refined fuel that runs in an environmentally friendly way in diesel engines.

The project is funded by a $2 million grant from the U.S. Department of Energy. The goal is to create biofuels that work in existing diesel engines to reduce greenhouse gas emissions by 60 percent compared to normal diesel fuels while improving engine thermal efficiency beyond the baseline diesel engine.

UM researchers will work with researchers from Penn State University and the University of Delaware on the three-year project that will test how to best grow algae, transform it into diesel fuel and maximize its performance during the combustion process.

The grant will help the team ultimately extract oil from the algae via mechanical presses or the use of ultrasonic waves, with UM's research team using an emerging technology called hydrothermal liquefaction to extract oil from the algae. Ultimately, the goal is to create a viable diesel fuel blend that can be a renewable energy source.

"This is now one of the few groups in the world that is taking algae all the way from literally growing it in a lab or outdoor cattle tanks," said Cardinale, a biology professor and director of UM's Cooperative Institute for Great Lakes Research, who is involved in the project. "We've got to get a stable crop that could be harvested on a routine basis. Then we've got to give it to chemical engineers, who can take the bio-crude we make from the algae and refine it so that it resembles the kind of fuel you would put in an engine."

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Jonathan Martin, a Ph.D candidate at the University of Michigan, tests diesel combustion in a GM 1.9L turbodiesel engine at the Walter E. Lay Automotive Engineering Laboratory, Wednesday, Oct. 10, 2018 in Ann Arbor. Photos by Ben Allan Smith

Researchers will then test how the fuel works in a diesel engine, measure its combustion properties and make sure it burns properly without emitting properties that are harmful to the environment to complete the end-to-end process.

The goal from an automotive perspective is to improve powertrain efficiency while the Department of Energy seeks improvements in the biodiesel alternative, UM W.E. Lay Automotive Laboratory Director Andre Boehman said.

"What we would like to do is have a fuel that doesn't so aggressively convert into soot when it's being burned," Boehman said. "Lowering the soot formation tendency of the fuel is one of the things we hope to accomplish with the algae-derived fuels."

The Department of Energy believes algae has the potential to produce billions of gallons per year of renewable diesel, gasoline and jet fuels. And that contribution could prove crucial to meeting Renewable Fuel Standards. By 2022, 36 billion gallons of transportation fuels sold in the U.S. must come from blended sources. Only 15 million of those can come from corn-based ethanol, leaving a sizable gap.

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UM ecologist Bradley Cardinale and two research assistants - Jessica Perry, left, and Brenna Boehman - measure light penetration in tanks containing various mixtures of freshwater algal species. Photo provided l Daryl Marshke/Michigan Photography

Traditional approaches to growing algae, Cardinale said, have taken place in a lab, where its genes can be tweaked and engineered to include all of the properties needed for combustible materials in biofuels like lipids.

That doesn't necessarily translate well once the algae is out in the environment. Instead, researchers have found that a combination of algal species performs better than any single species, capitalizing on the individual strengths of each strain.

Prior to this project, Cardinale and UM researchers have spent time testing combinations of algal species for their biofuel viability at the university's E.S. George Reserve near Pinckney, where various combinations of species glowed neon green in 80, 290-gallon cattle tanks in another federally-funded project.

"What we find is whenever we try to genetically engineer these things and put them out in the environment, Mother Nature ruins it because it's not something she created naturally in the first place," Cardinale said. "So, what we're doing is finding the different combinations of species that produce a lot of yield, that can resist disease and that have the chemical properties together that are ultimately good for engines. Once we find them, we can use ecological design to create the material for an engine that's good for the environment."

From there, the teams will investigate how the resulting compounds can best be turned into biocrude synthetic fuel.

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University of Michigan Prof. Andre Boehman discusses converting algae into biofuel at the Walter E. Lay Automotive Engineering Laboratory, Wednesday, Oct. 10, 2018 in Ann Arbor. Photos by Ben Allan Smith

In order to optimize the fuel's combustion and emissions performance, researchers will look at both the biochemical properties of the algae as well as their chemical reactions in the controlled compression ignition combustion environment of the diesel engine. The biofuels will be tested in a light duty vehicle engine and, once an optimal algae combination is determined, it will be tested in a Volvo truck engine.

Boehman said he expects algae to produce similar, if not better, renewable energy content than first-generation biodiesel fuels from soy, corn and fish oils.

It also has the potential of growing in more concentrated quantities. Boehman estimated that 3,000 gallons of algae can be yielded from one acre, compared to around 90 gallons of soy oil per acre.

"We're talking about a large potential expansion in capacity," he said. "In the U.S. we're going through 20 million barrels of oil a day. That's a lot of stuff to replace."

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Former UM undergraduate research assistants Brenna Boehman, left, and Jessica Perry filter algae collected from large tanks at the university's E.S. George Reserve near Pinckney. Photo provided l Daryl Marshke/Michigan Photography.

Cardinale said the current political climate is not necessarily friendly toward the creation of renewable energy and moderating the climate.

He does believe, however, that the results of their work could speak for themselves if proven to be financially viable.

"As soon as it becomes clear to large companies like Exxon and Shell and others that this is a commercially viable process that is going to potentially make them money, then the oil lobby, which is currently having a big influence on our policies, is also going to start lobbying for renewable energy," he said. "One of the goals of our project is to work with these companies to see if we can get closer to commercial viability."

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