Biofuel production can be more efficient in combination with hydrogen
The production of renewable fuels can be increased by more than 40 per cent without having to cultivate a single square metre more of land. So says a new international study that analysed the production of biofuels from sugar cane in Brazil. By combining ethanol production from sugar cane with hydrogen, the CO2 released during ethanol production could be converted into methanol. In these times of energy scarcity, this way of producing biofuel could offer a hopeful alternative.
Ethanol is a biofuel based on sugar cane that has been sold in Brazil as a car fuel for over 50 years. "Currently, ethanol production generates large surpluses of CO2 during fermentation. By combining this CO2 with hydrogen obtained from solar and wind power, you can make methanol. Another fuel," explains Luis Ramirez Camargo, scientist at Utrecht University and lead author of the study. Methanol is currently mainly used in the chemical industry, but in the future it could also be used in ship engines, for example.
Downside
There is a significant and well-known downside to biofuels. For example, the production of sugarcane ethanol comes with a whole series of socio-ecological problems. On the one hand, there is direct competition with food and feed production for arable land, which causes land conflicts, for example with the traditional use of small family farms. On the other hand, large-scale monoculture such as sugarcane plantations brings with it a series of ecological hazards such as deforestation and loss of biodiversity. "Our analysis shows that the use of classical bioenergy in combination with modern hydrogen technologies has great potential to save land. In this way, biodiversity and traditional land use can be preserved and competition with food production reduced. However, this requires policies that actively protect and promote alternative land uses. Otherwise, synthetic fuels can also have negative consequences," says Johannes Schmidt from the Institute for Sustainable Economic Development at the University of Natural Resources and Life Sciences in Vienna.
Costs
However, this technology also comes at a price: large renewable energy plants, electrolysers and storage facilities for CO2 and hydrogen would have to be installed. At the time of the study, avoiding one tonne of CO2 with this method would have cost around €200 - more than twice the wholesale price of CO2 emissions in Europe. However, recent fossil fuel price increases have caused the price of methanol to rise sharply. Under current conditions, the European wholesale price of CO2 emissions would be sufficient to finance the technology. Assuming that the cost of solar cells and electrolytic cells continues to fall, costs could also drop by 40% over the next decade.