This Carbon-Negative Biofuel Might Ultimately Replace Coal
November 26, 2024
In Joensuu, a city in Eastern Finland often described as the ‘Forest Capital of Europe,’ the largest torrefaction factory on the continent is nearing completion. (Torrefaction is a thermal process that degrades organic material into a renewable energy source.)
When the factory becomes operational in a few months’ time, it will be capable of producing 60,000 tons per year of a novel biofuel known as NextFuel briquettes, and its construction is regarded as a giant leap forward for a fuel source with the potential to transform industries as diverse as cement, power generation, and perhaps eventually, aviation.
Biofuels have been on the agenda at the past week’s United Nations Climate Change Conference (COP29). According to next year’s host Brazil, a country where biofuels in the form of ethanol already make up 25 per cent of all transportation fuels, the continued expansion of biofuels will play a key role in their stated aims to reduce carbon emissions by 67% over the next 11 years compared with 2005 levels.
While Brazil is yet to give concrete examples of additional biofuels which could be used alongside ethanol, it is hoped that liquefied biofuels will continue to displace oil, and various companies have been pioneering new innovations in this sector. One example is the company CoverCress, which received an investment from my team at Leaps in 2015 and is now majority owned by Bayer. Using advanced breeding and gene editing tools, CoverCress has developed a method of transforming field pennycress from a weed into a new cash crop, enabling it to be harvested and crushed into a seed oil that can then be turned into a renewable diesel and sustainable aviation fuel.
Torrefaction is another process that is gaining attention as a way to harvest biofuels because it turns solid biomass into a coal-like substance. Last year, global coal consumption reached a record high of 8.7 billion tons, and finding viable alternatives remains a major hurdle in the push for Net Zero. “The biggest advantage of torrefaction is that it produces this fuel which can be used in similar infrastructure to coal, while it’s also easy to transport and store,” says Wei-Hsin Chen, a researcher at Taiwan’s National Cheng Kung University, who has published various reviews examining the potential of torrefaction.
An Energy Breakthrough
So far, torrefaction’s applications have been relatively limited, mainly because most projects have relied on wood pellets as the dominant source of biomass. While it is impossible for many countries to obtain the vast volumes of waste wood needed to replace coal, the majority of climate scientists and environmentalists are heavily opposed to the burning of wood for energy. As well as being less energy efficient than coal in terms of power, wood actually emits 18% more CO2 for every KWh of energy generated.
But in 2016, a company called NextFuel, which was established as a Scandinavian-Austrian consortium, developed a solution that they believe will finally make torrefaction-based biofuel generation commercially viable. Their method, which was first unveiled to considerable fanfare at COP24, can generate briquettes of fuel using any type of feedstock, from sugarcane leaves to elephant grass.
Having spent several years in stealth mode, refining their technology and conducting feasibility studies across various industries including cement and steel, the Joensuu factory will soon allow them to demonstrate its capabilities at scale for the very first time.
“If you want to replace coal, you need to be scalable, profitable, and quite close in energy content,” explains NextFuel’s co-founder Audun Sommerli Time. “Black coal is around 24-31 gigajoules per ton, wood pellets are around 15-17 gigajoules per ton and our fuel is between 22 -28 gigajoules per ton, which is much closer.”
The Promise of Elephant Grass
Miscanthus × giganteus, to use the Latin name for the most popular species of elephant grass, has long been eyed as a potential raw material for solid biofuels. Capable of growing to heights of four meters in a single season and able to thrive on marginal land, it can provide yields which are infinitely more efficient than wood. Mr. Time believes NextFuel briquettes can compete with coal on a cost basis even before carbon taxes, but cultivating plantations of elephant grass offers tantalizing additional carbon sequestration benefits. One study predicted that replacing arable land with Miscanthus × giganteus plantations could sequester between two and three metric tons of carbon per hectare every year in the plants’ underground roots.
NextFuel’s other key selling point is that the briquettes produced can be directly incorporated into existing power degeneration facilities which have been designed for coal, removing the need to invest in new infrastructure. “One of the reasons why the climate challenge is being solved so slowly is the need to build new utility grids, spend a lot of money on new infrastructure,” says Mr. Time. “But with our products, there’s no need for any upgrade. You can just switch fuel which makes it easier to adopt by industries and politicians because you’re not hurting economic growth.”
With the Joensuu factory representing an important next step, NextFuel has even more ambitious plans in mind. One example is a client’s plan of constructing factories in East Africa fueled by elephant grass and waste feedstock, which are capable of generating up to 1.5 million tons of NextFuel briquettes per year. According to Mr. Time, this would make it possible to directly replace coal across the region.
If it succeeds, it would be a particularly landmark moment for sustainable biofuels as at present, countries like Ethiopia are reliant on coal imports, primarily from South Africa. Araya Asfaw, a sustainability researcher at Addis Ababa University, says that the prospect is extremely appealing although she is not completely convinced that torrefied biomass can totally replace fossil fuels.
“Torrefaction of wild grass can provide clean and sustainable energy while protecting the grassland ecosystem,” she says. “I think it can replace fossil fuels for household energy, which represents more than 80% of the primary energy requirements.”
Ultimately NextFuel envisions a world in which much of the agricultural waste in the local region is recycled and used for generating biofuel through torrefaction. While elephant grass and waste from sugarcane might be used in South America, wheat straw and maize could be used in parts of the U.S., and leftover paddy straw from rice fields in India. The company is also investigating potential industrial partnerships which would enable them to convert NextFuel briquettes into a liquid form via a chemical reaction known as the Fischer-Tropsch process, enabling it to be used as a sustainable aviation fuel.
With the European Union actively working towards transitioning to advanced biofuels made from sustainable feedstock, and requirements set for all member nations to shift 29% of their transport energy generation from fossil fuels to renewable sources by 2030, NextFuel is hoping that it can play a key role in the solution.
“Our long-term ambition is for this to be the next fuel after fossil fuel has dominated the last two centuries,” says Mr. Time. “Of course, you need a lot of NextFuel factories before that can happen, but it’s possible.”
Thank you to David Cox for additional research and reporting on this article.
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