Taken from the bottom of the marine food chain, microalgae may soon become a top-tier contender to combat global warming, as well as energy and food insecurity, according to a study by researchers associated with the Cornell Algal Biofuel Consortium, published in the journal Oceanography (December 2016).
“We may have stumbled onto the next green revolution,” said Charles H. Greene, professor of earth and atmospheric sciences, and lead author of the new paper, “Marine Microalgae: Climate, Energy and Food Security From the Sea.” The study presents an overview to the concept of large-scale industrial cultivation of marine microalgae, or ICMM for short.
ICMM could reduce fossil fuel use by supplying liquid hydrocarbon biofuels for the aviation and cargo shipping industries. The biomass of microalgae remaining after the lipids have been removed for biofuels can then be made into nutritious animal feeds or perhaps consumed by humans.
To make the biofuel, scientists harvest freshly grown microalgae, remove most of the water, and then extract the lipids for the fuel. The remaining defatted biomass is a protein-rich and highly nutritious byproduct – one that can be added to feeds for domesticated farm animals, like chickens and pigs, or aquacultured animals, like salmon and shrimp.
After consuming the algae-supplemented feeds, chickens produce eggs with three times the omega-3 fatty acids, according to previous Cornell research.
Growing enough algae to meet the current global liquid fuel demand would require an area of about 800,000 square miles, or slightly less than three times the size of Texas. At the same time, 2.4 billion tons of protein co-product would be generated, which is roughly 10 times the amount of soy protein produced globally each year.
Marine microalgae do not compete with terrestrial agriculture for arable land, nor does growing it require freshwater. Many arid, subtropical regions – such as Mexico, North Africa, the Middle East and Australia – would provide suitable locations for producing vast amounts of microalgae.
A commercial microalgae facility of about 2,500 acres would cost about $400 million to $500 million. Greene said: “That may seem like a lot of money, but integrated solutions to the world’s greatest challenges will pay for themselves many times over during the remainder of this century. The costs of inaction are too steep to even contemplate.”
Microalgae’s potential is striking. “I think of algae as providing food security for the world,” said Greene. “It will also provide our liquid fuels needs, not to mention its benefits in terms of land use. We can grow algae for food and fuels in only one-tenth to one one-hundredth the amount of land we currently use to grow food and energy crops.
“We can relieve the pressure to convert rainforests to palm plantations in Indonesia and soy plantations in Brazil,” Greene said. “We got into this looking to produce fuels, and in the process, we found an integrated solution to so many of society’s greatest challenges.”
TAU researchers discover algae can yield mass quantities of hydrogen, the world’s cleanest energy source
Researchers at Tel Aviv University have revealed how microalgae produce hydrogen, a clean fuel of the future, and suggest a possible mechanism to jumpstart mass production of this environmentally-friendly energy source. Their results have been published in back-to-back studies in Plant Physiology and Biotechnology for Biofuels.
The research was led by Dr. Iftach Yacoby, head of TAU’s renewable energy laboratory, and Rinat Semyatich, Haviva Eisenberg, Iddo Weiner and Oded Liran, his students at the School of Plant Sciences and Food Security at TAU’s Faculty of Life Sciences.
Researchers in the past believed that algae only produce hydrogen in the course of a single microburst at dawn lasting just a few minutes. But Dr. Yacoby and his team used highly sensitive technology to discover that algae produce hydrogen from photosynthesis all day long. Armed with this discovery, the team harnessed genetic engineering to increase algae’s production of this clean energy source 400 percent.
Increasing algae’s output of hydrogen
Laboratory tests revealed that algae create hydrogen with the assistance of the enzyme hydrogenase, which breaks down when oxygen is present. The researchers discovered effective mechanisms to remove oxygen so hydrogenase can keep producing hydrogen.
“The discovery of the mechanisms makes it clear that algae have a huge underutilized potential for the production of hydrogen fuel,” said Dr. Yacoby. “The next question is how to beef up production for industrial purposes — to get the algae to overproduce the enzyme.”
Some 99% of the hydrogen produced in the US comes from natural gas. But the methods used to draw hydrogen from natural gas are toxic — and wasteful.
Answering the need for clean energy
“I grew up on a farm, dreaming of hydrogen,” said Dr. Yacoby. “Since the beginning of time, we have been using agriculture to make our own food. But when it comes to energy, we are still hunter-gatherers. Cultivating energy from agriculture is really the next revolution. There may be other ways to produce hydrogen, but this is the greenest and the only agricultural one.
“The world burns in just one year energy it took the earth over a million years to produce,” Dr. Yacoby continued. “We must stop being hunters and gatherers of energy. We must start producing clean energy — for our children and for our children’s children.”
Dr. Yacoby is now researching synthetic enzymes capable of increasing hydrogen production from microalgae to industrial levels.
Microalgae consist of single cells but are capable of producing everything from food to fuel with the help of tailor-made LED-lighting.
“We’re working to synthesise raw materials for biofuels, cosmetics and health food, and ingredients which can replace fish oil in fish farm feed, by means of so-called phototrophic production using algae,” says Andreas Hagemann, a SINTEF research scientist.
“We extract Omega 3 fatty acids from fish which absorb them from their food, such as small crustaceans, and which in turn have obtained them by grazing on microalgae”, he says.
Hagemann is standing in his lab in Trondheim, Norway, beside something which looks like a glowing advertising sign, but which in fact consists of small light panels covered with light-emitting diodes.