World map of relative liquid fuel production potential from microalgae, with production potential increasing from blue to orange; many arid environments in the world’s subtropical coastal regions provide an ideal setting for large-scale cultivation of marine microalgae. Click to enlarge.

Agroup of educators and researchers from Cornell University, the Cornell Algal Biofuel Consortium (CABC), has published a comparative commentary in the December, 2016 issue of Oceanography, the quarterly journal of The Oceanography Society.

The commentary sums up a tremendous amount of integrated research and life-cycle analysis, and examines the state of BioEnergy with Carbon Capture and Storage (BECCS). The primary message in this publication is that “…large-scale industrial cultivation of marine microalgae can provide society with a more environmentally favorable approach (than BECCS) for meeting the climate goals agreed to at the 2015 Paris Climate Conference, producing the liquid hydrocarbon fuels required by the global transportation sector, and supplying much of the protein necessary to feed a global population approaching 10 billion people.”

“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 from phytoplankton for the aviation and cargo shipping industries, the report suggests. 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.

Microalgae exhibit rates of primary production that are typically more than an order of magnitude higher than the most productive terrestrial energy crops. Scaling up production numbers from demonstration-scale cultivation facilities, the current total demand for liquid fuels in the United States can potentially be met by growing microalgae in an area of 392,000 km2, corresponding to about 4% of US land area, or just over half the size of Texas, according to the report.

For microalgal bioenergy to be cost competitive with fossil fuels, the report underscores, it must be produced with sufficiently valuable co-products. Animal feeds are one type of co-product that has a global market of appropriate scale and value, 1 gigaton per year and $460 billion per year, respectively (Alltech Global Feed Survey, 2015). However, by mid-century, the protein demands for a global population of 9.6 billion people will be unsustainable with today’s conventional industrial agricultural practices, especially with anticipated future constraints on the use of fossil fuels.

In contrast, ICMM can provide the basis for a new “green revolution.” To gain a sense of its potential, from the same 392,000 km2 needed to meet the current total liquid fuel demand of the United States, 0.490 gigatons of protein could be produced. This corresponds to about twice the total annual global production of soy protein.

The group identified many arid, subtropical regions – such as Mexico, North Africa, the Middle East and Australia – that would provide suitable locations for producing vast amounts of microalgae.

Microalgae’s potential is striking said Dr. Greene. “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,” he 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.”

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