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Biofuel production would become more efficient in combination with hydrogen

  • June 15, 2022

The scientific journal 'Nature Communications' published the paper 'A Pathway to a land neutral expansion of Brazilian renewable fuel production'. Lead author and MOBI-researcher Luis Ramirez Camargo explains: "With this study we show that the fuel output of Brazilian sugarcane ethanol facilities may be increased by over 40% without using additional land if production is combined with synthetic fuel processes. This amounts 100TWh of fuel, sparing 27,000 km2 of land."

Ethanol has been produced from sugarcane as fuel for vehicles since the 1970s in Brazil. This has negative consequences for the environment. By combining it with photovoltaic or wind power plants, which are used to produce hydrogen, the CO2 that is produced during the ethanol production could be synthesized into methanol. This could increase fuel production by more than 40 percent.

An area one third larger than Belgium is used to grow sugarcane in South America's largest country. Monocultures dominate those approximately 40.000 square kilometers, and their expansion puts further pressure on the country's natural areas, which have already been pushed back significantly. This is a real danger, as Brazil has been expanding production since many countries began to rely on fuels from renewable sources.

'Variety of socio-ecological problems'

This is associated with a 'multitude of socio-ecological problems'. "On the one hand, it is in direct competition with food and animal feed production due to the increasing competition for arable land, which subsequently causes land conflicts, for example with traditional uses of small family farms. On the other hand, large-scale monoculture cultivation poses a series of ecological dangers", says Michael Klinger of the Institute for Sustainable Economic Development at Boku (University of Natural Resources and Life Sciences in Vienna), who contributed to the study with scientists from Brazil, Sweden and Belgium.

In addition, ethanol production generates a lot of CO2. The idea of the researchers collaborating with the lead author of the paper, Luis Ramirez Camargo (VUB, MOBI), is to use carbin dioxide for a further processing step: "If hydrogen was available, you could could combine it with CO2 and produce methanol from it. This substance is currently used primarily in the chemical industry, but could also power, for example, ship engines in the future."

"If hydrogen was available, you could combine it with CO2 and produce methanol from it. This substance is currently used primarily in the chemical industry, but could also power, for example, ship engines in the future."

Combination of photovoltaic and wind power plants

If photovoltaic or wind power plants were to be operated on a small part of the current sugarcane cultivation area, the electricity generated from the process could in turn keep electrolysis plants running to produce hydrogen, and the methanol production could also be added to the ethanol production. The effect would be an increasement of total production by at least 43 percent while maintaining the same acreage. The scientists identified a combination of photovoltaic and wind power plants as the most cost-effective variant.

Of course, theseĀ and the electrolysis units would first have to be installed and the double production would have to be operated in such a way that acceptable prices could be achieved. On the one hand, the recent rise in methanol prices would bring us closer to this goal, and on the other hand, price reductions for photovoltaics and electrolysers can be expected in the near future. The researchers believe that the concept that has now been developed has potential - even outside Brazil. "In this way, biodiversity and traditional land uses can be preserved, and competition with food production can be reduced. This requires however a policy that actively protects and promotes alternative land uses", says Johannes Schmidt from Boku.

Click here to read the study.

Copyright photo: BOKU/Inst. f. N. W.