Farming News - Microalgae: food and fuel of the future?

Microalgae: food and fuel of the future?

23 Nov 2016
Frontdesk / Renewables

A professor from Cornell University in the United States has estimated the potential for industrial cultivation of micro-algae to change fuel and - potentially - food production.  

New research from the US suggests that micro-algae, taken from the bottom of the marine food chain, may soon become a top-tier contender to combat global warming, climate change and food insecurity.

Charles H. Greene, professor of earth and atmospheric sciences at Cornell University, who has studied the miniature plant said, ”We may have stumbled onto the next green revolution - Marine Microalgae - [which could provide] Climate, Energy and Food Security From the Sea."

Prof Greene has looked into the potential for large-scale industrial cultivation of marine microalgae, which could be used to produce ‘third generation biofuels’ - a newer cleaner type of sustainable fuel, which are moving closer as techniques for reliably producing algae improve.

MicroalgaeFirst generation biofuels, which come from crop plants, see food and fuel competing for a finite amount of growing space on the Earth’s surface, and there are still issues of pollution associated with their use (especially vegetable-based fuels). Second generation biofuels are made from ‘biomass’ (any source of organic carbon) including crop wastes. Algae was previously lumped in with second generation biofuels, but experts now believe it might be the best contender for advanced biofuels, and, according to Prof Greene, could be made into food for livestock or humans: according to Greene, the microalgae remaining after lipids have been removed to create biofuels can then be made into nutritious food or feed.

Although it may sound like Soylent Green, the Cornell Professor believes micro algae represents a source of untapped potential. Greene said, "I think of algae as providing food security for the world. 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. 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."

How is it done?

To make the biofuel, scientists harvest freshly grown microalgae, remove most of the water, and then extract lipids (fatty acids) for the fuel. The remaining defatted biomass is protein-rich, and can potentially be used as a supplement for a range of livestock.

According to Greene’s 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 the protein ‘co-product’ would be generated by this process (roughly 10 times the amount of soy protein produced globally each year).

In terms of feasibility, many arid, subtropical regions including such as Mexico, North Africa, the Middle East and Australia are suitable locations for producing vast amounts of microalgae. Other benefits of the potential crop, outlined by Prof Greene, are that production wouldn’t compete with terrestrial agriculture land - like all first and some second generation biofuels do - and that algae can be produced without fresh water, which is in short supply in most of the world’s major crop producing regions, and many population centres.

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.”

What’s the emissions impact?

Even so, climate experts have said there’s a need for a shift not only in the type of fuel we consume, but also in our consumption patterns, to reduce the amount of atmospheric carbon, and tackle the impacts of accelerating climate change. Speaking to Farming Online on Wednesday, Prof Greene said that shifting to algae-based fuels could have environmental benefits if reductions in emissions are realised elsewhere; he said “In this paper, we assume that society takes the best pathway forward and completely powers its electrical grid with renewables and also completely electrifies its light vehicle fleet.”

He pointed to research conducted by colleagues at Stanford University, which shows this can be achieved by 2050 (in the USA at least), and said, “If society does that and strongly ramps up microalgae biofuel production to cover aviation, shipping, and heavy vehicles, then I think it can eliminate the emissions of new fossil carbon from all energy sources into the atmosphere, and even become carbon negative.” He qualified this, though, adding, “Of course, what is possible and smart is not necessarily what society will do.”

Prof Greene acknowledged that though “cultivation [of algae] requires significant energy inputs”, and said his colleagues are planning a thorough analysis of different future energy use scenarios, with algae-based fuels in the mix, but said previous research has demonstrated that, given the right conditions, this renewable biofuel can lead to emissions reductions.