With energy prices soaring and concerns rising over security of supply in Europe, it is more important than ever to develop sustainable, accessible fuel sources.
One chemical compound that has long played a key role in decarbonizing the energy sector is ethanol. Ethanol is already widely used in transportation, where it is mixed with gasoline to oxygenate the fuel and reduce emissions.
It is thought that ethanol could play a crucial role in “plugging the gaps” in the power market as we strive for net zero. However, producing sustainable ethanol at a large enough scale to achieve this task has remained elusive thus far.
To solve this problem, researchers at LUT teamed up with scientists in the research group for regenerative energy systems at the Technical University of Munich (TUM) to develop a new method for ethanol production.
Instead of the traditional, lengthy processes that involve slowly fermenting sugar, the researchers came up with a method for producing large quantities of ethanol using wood waste from the Finnish forestry sector, combined with hydrogen from electrolysis.
According to Kristian Melin, an assistant professor in the processing and plant design of biorefineries at LUT, this novel method offers cost-effective solutions to the complex problems facing the global energy market.
Old ideas, new tricks
“Since we can no longer rely on fuel imports from Russia, we need to turn to local, sustainable energy sources”, Melin explained, adding that Finland’s vast forestry industry provides a rich source of waste wood that can be broken down into ethanol.
While some big players in the energy industry have been using waste wood such as tree bark to produce ethanol for a while now, their methods tend to rely on enzymes to break down the bark into fermentable sugars, that yeasts then turn into ethanol. This is generally a very slow process that produces a low yield of usable fuel.
For Melin, one of the key benefits of his group’s new method, which involves the gasification of wood combined with electrolysis instead of enzymes, is that it can produce much more fuel from the same amount of wood.
“With traditional methods, you get maybe 200 or 300 liters of ethanol per ton [of waste wood]. But our method yields up to six times as much ethanol per ton, making it more attractive for fuel producers, since less raw material is needed”.
A key reason for this is that LUT’s method uses the entirety of the wood product, meaning that there are far fewer useless by-products at the end of the process. The method also makes it easier to store the energy produced for later use, such as when energy demand exceeds supply from other sources.
A scalable solution to energy market problems
When it comes to commercial production, Melin acknowledges that there is still a long way to go. He estimates that it will take five to ten years for the first commercial plant to be up and running, but that such a plant in Finland would easily be capable of turning 50,000 dry tons of biomass into 70 million liters of useable fuel per year.
“Some Diesel trucks can already run on 95% ethanol, which in itself makes it clear why now is the time to scale up production in Finland. We need to turn our attention towards practical, near-term solutions such as this, instead of throwing all our resources at electric cars”, Melin added.
The fuel produced by the LUT research group can also be converted into jet-fuel for commercial jets, as well as in shipping vessels and as raw material to produce green plastics and packaging. Melin believes that fuel companies, energy providers, forestry producers, and transportation businesses can all benefit from this research.
Facilitating the green transition
While the time horizons might seem far off, taking advantage of these solutions now could reap significant benefits further down the line. Biomass-derived fuel could be used to quickly support the energy system when wind or solar power is not sufficient.
Biomass fuels can also be used to keep prices down for households and businesses alike when gas and petroleum prices are high, or to reduce the carbon footprint of those fossil fuels as we make the green transition. This flexibility is one of the main reasons why the LUT research group began looking into wood-based ethanol fuels in the first place.
Melin also strongly believes that LUT’s unique strengths are what have made this project possible, noting that the natural curiosity of the team means that “spontaneous ideas often become real solutions”.
“The talent in our energy and separation technology departments is incredibly strong, and the university’s emphasis on collaboration with industry has yielded game-changing results”, he explained.
“More than anything, it’s the positive atmosphere. We are all doers, and we are keen to work with anyone who is ready to pursue real innovation in these vital sectors”.
