Clean, green, microscopic and marine: next-generation biofuels

Solazyme's hand-picked microalgae strains are the basis of its sustainable biofuels.
Solazyme's hand-picked microalgae strains are the basis of its sustainable biofuels.
Solazyme

Corn and oilseed-based biofuels are so last decade. Now, we have a whole new crop of cleaner, greener biofuels based on microscopic marine plants - and even more miniscule critters.

Back in January 2010, algae biofuels and biotech expert Dr Stephen Mayfield, Director of the California Center for Algae Biotechnology at the University of California (UC) San Diego and Co-director of Food & Fuel for the 21st Century was interviewed for University of California Television (UCTV), and was excited about the potential of using algae as a biofuel feedstock. Back then, the estimated cost of producing algae-based biofuels was prohibitively costly and, as Dr Mayfield noted, there were some significant challenges to reaching commercial viability.

Since 2010, substantial efforts and funds have been directed towards R&D into algae-based biofuels, much of it by a US Department of Energy-initiated consortium of academic and industry bodies known as the National Alliance for Advanced Biofuels and Bioproducts (NAABB). Between 2010 and 2013, NAABB conducted extensive research and development spanning the production chain from algal biology to fuel conversion, in an effort to:

  • create more robust, salt- and drought-tolerant, productive oil-rich algae strains;
  • boost and speed production;
  • reduce input costs, including water and energy requirements; and
  • improve algae harvesting, extraction, and fuel conversion and production methods.

Innovations and improvements were shown across the entire value chain, including technologies that maximised biomass productivity and improved algae cultivation methods. Direct pathways to fuels were shown to be the most feasible, minimising the high energy consumption dewatering algae entails and maximising carbon input into the final fuel.

Advances in key areas enabled the NAABB consortium to reduce the costs of producing algae bio-crude oil from a baseline US$240 per gallon in 2010 to a far more affordable US$7.50/gallon in 2013.

This cost needs to drop significantly, however, before algae-based biofuels will be economically viable on a mass scale, NAABB contends in its 2014 Final Report. And that means more R&D.

“Additional productivity and cultivation gains will be needed to further reduce the cost of biocrude to under $2 per gallon,” the report’s authors state. “A successful algal production farm requires a new approach to construction and cultivation that drastically reduces the cost of construction and its effect on capital layout.

“Furthermore, the algal farms must implement algae strains and cultivation methods that maximize biomass productivity year-round. Finally, the use of major resources, such as key nutrients and water, need to be minimized and efficiently utilized.

“Combining technologies and systems in these three areas into a model integrated production and biorefinery system will bring viable algae-based biofuels into the market.”

Direct-to-ethanol technology paves way to viable high-grade algal biofuels

One company hoping to benefit from pioneering algae-to-biofuel technology is Algenol Biofuels, a Florida, US-based start-up that, in conjunction with scientists from the University of Toronto, developed innovative technology that’s giving it a head start in the next-gen-renewable-biofuels stakes.

Algenol’s patented Direct to Ethanol® technology is a two-step process:

  1. Enhanced blue-green algae (cyanobacteria) uses photosynthesis to convert sunlight, CO2 and seawater into a sugar known as pyruvate, then to ethanol;
  2. The leftover algae biomass is converted to biodiesel, gasoline and jet fuel.

The new proprietary technology enables Algenol to produce the four most commercially important transport fuels for about US$1.27 per gallon, claims the company’s website. What’s more, the site states, it’s the only renewable fuel production process able to convert more than 85 percent of its CO2 feedstock into these key fuels.

Algenol Biofuels’ CEO Paul Woods says the new technology enables the company to produce an impressive 9,000 gallons of liquid fuel per acre, per annum, far more than the output of competing biofuel feedstocks such as corn, from which just 420 gallons of biofuel can be produced per acre, per year; and sugarcane, which yields around 800-820 gallons/acre/year.

All it takes is a suitable strain of algae, sunlight, carbon dioxide (CO2), saltwater and non-arable land, Woods told Nature World News (NWN) in 2014. The right conditions – moderate temperature and sufficient light and water – are required, but compared to its terrestrial-crop competitors, algae’s a highly manageable biofuel crop.

Finding the right algae for the job was an important part of the process: Woods and his colleagues found an optimal host strain after an exhaustive search for potentially suitable candidates that entailed sifting through 2,300 algae strains.

Algenol’s Woods is confident algae biofuels are the way of the future. "Like all natural progressions we'll move away from … taking food and making fuel out of it into something … a lot more advanced," he told NWN.

The new algae-to-biofuels process is simple, eco-friendly and cost-efficient, and has been “conclusively proven” to be safe, Woods assured.

Solazyme patents high-tech method for producing high-performance algae-based transport fuels

Another US company poised to profit in the algae-derived biofuels stakes is San Francisco-based Solazyme.

The company is producing various high-performance fuels from microalgae, including:

  • SoladieselBD® which can be used in factory-standard diesel engines with no modification, significantly outperforms ultra-low-sulphur diesel in total THC, carbon monoxide and particulate matter tailpipe emissions, and runs better in chilly weather than any commercially available biodiesel;
  • SoladieselRD®. a drop-in alternative to standard diesel fuels chemically indistinguishable from petrol-based diesel, the fuel’s emissions contain fewer particulates and meet US standards for ultra-low sulphur diesel; and
  • Solajet, a renewable aviation fuel refined from Solazyme’s algal oil, that the company claims is “the world’s first microbially-derived jet fuel to meet key industry specifications for commercial aviation”, is compatible with existing infrastructure but delivers “a faster, farther and greater payload; reduced wing-heat stress; lower flammability; lower smoke emissions; longer storage life; and ultimately, lower maintenance cost”.

Solazyme’s even working with the US Department of Defense to develop sustainable, algae-based military-grade biofuels – jet fuel, marine diesel and on-road diesel that have been rigorously tested by the US Navy and shown to meet its specifications.

True-blue ‘green crude’

Late in 2014, an integrated algae-oil test plant was launched in Whyalla, South Australia by SA-based renewables company Muradel Pty Ltd. The plant will pilot commercial-scale production of algae-derived crude oil with a view to establishing a commercial plant with the capacity to produce 80 million litres of eco-friendly ‘ green crude’.

The $10.7 million demo plant is expected to turn out 30,000 litres of oil a year, deploying Muradel’s Green2Black™ technology that converts naturally-occurring marine microalgae to biofuel, quickly, cheaply and sustainable.

The technology for growing the microalgae has been developed by Muradel’s partners over the past eight years, and piloted since mid-2013 on a continuously operating two-acre open-pond pilot plant near Karratha, Western Australia.

Muradel’s subcritical water reactor technology takes microalgae grown sustainably in seawater ponds on site and mixes it with plant biomass and organic waste, converting them to a crude bio-oil that’s functionally equivalent to fossil-fuel crude in minutes. The algae ponds also act as carbon sinks that can capture greenhouse gas emissions produced by Whyalla’s heavy industry, says Dr Lewis.

The resulting oil can be refined using standard methods to produce low-net-carbon liquid transport fuels – including petrol, diesel and aviation fuels – that are cost-comparable to their fossil-fuel equivalents.

If the Whyalla-based demonstration plant can be scaled successfully to commercial levels, it will be capable of producing 500,000 barrels of refinable green crude a year by 2019, says Muradel CEO and University of Adelaide Associate Professor Dr David Lewis.

That’s the equivalent of the petrol and diesel fuel that would be required to fuel 30,000 vehicles over an entire year, at production costs equivalent to those of fossil fuels.

“This is world-leading technology which can be scaled up exponentially to help steer our fossil fuel-dependent economy to a more sustainable future,” Dr Lewis said.

Muradel's algae oil production system in action.
Muradel's algae oil production system in action.
Muradel via YouTube

The new Whyalla project isbacked by a $4.4 million grant from the Australian Renewable Energy Agency (ARENA), and in-kind and financial support from Whyalla City Council, the Government of South Australia and Muradel shareholders.

The planned 1,000-hectare commercial plant is expected to create at least 100 new skilled and operational jobs in the region.

Dr David Lewis explains the project in detail in this ABC-Radio Adelaide audio clip.

The real proof, however, will be in sales of algae-based biofuel – and as distinct from ‘green-leaning’ Europeans, Americans and Aussies want bang as well as environmental cred for their fuel buck.

It remains to be seen whether algae-based biofuels will be competitive on a mass scale with traditional fuels. Dr Lewis believes that time is at least a decade away - though Algenol and Solazyne both promote their technology as cost-effective and are keen to commercialise it on a broad scale.

Eventually, says the Algae Fuels Report – Processes, Technologies, Trends and Challenges, sales of algae-based biofuels could eclipse those of ‘traditional’ biofuels and even replace even fossil fuels as global oil supplies dwindle. If that occurs, the global algae-based biofuels industry could be worth trillions.

The next big (or should we say small?) biofuel thing...

A sewage treatment plant: the spent bodies of bacteria from such facilities could provide the next big biofuel feedstock, contends University of Adelaide Associate Professor and biofuels expert Dr David Lewis
A sewage treatment plant: the spent bodies of bacteria from such facilities could provide the next big biofuel feedstock, contends University of Adelaide Associate Professor and biofuels expert Dr David Lewis
David Weekly, Flickr CC, wwwflickrcomphotosdweekly

Don’t get overly excited about the prospects for algae-based crude, though: there's another contender, and it's even smaller and more sustainable than microalgae. Dr Lewis is also exploring the feasibility of using biosolids – the bodies of bacteria in wastewater treatment plants – as an alternative biofuel feedstock that could prove the most eco-friendly and cost-effective to date, with potentially valuable by-products and zero waste.

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