Ethanol is usually produced by the fermentation of sugars from starchy raw materials such as corn, or from lignocellulosic biomass, such as wood or straw. It is a fuel that can make the transport sector CO2-free. In collaboration with the Lappeenranta-Lahti University of Technology (LUT) in Finland, researchers from the Straubing Campus for Biotechnology and Sustainability of the Technical University of Munich (TUM) in Germany have developed a new process for the production of ethanol, the TUM said in a press release. The findings have been published in the medium Frontiers in Energy Research.
Hydrogen is needed to make fuel from forestry waste. Hydrogen is produced through electrolysis. In the future, surplus electricity will have to be used for this. “The total process mainly consists of technically mature sub-processes. However, the composition of the process steps and the final step – the hydrogenation of acetic acid to produce ethanol – are new,” explains Daniel Klüh, PhD candidate at the Renewable Energy Systems Professorship on the TUM Straubing campus.
Costs
The researchers also assessed the economic feasibility. “The prices we have calculated are based on assumptions for raw materials and energy. We do not use current market prices. The calculation basis for our prices for the components in the chemical system is the year 2020,” says Klüh.
The lowest costs for ethanol in the modeling were 0,65 euros per liter, with biomass costs of 20 euros per megawatt hour, electricity costs of 45 euros per megawatt hour, and a production volume of approximately 42 kilotons of ethanol per year.
“With the current options for the production of lignocellulosic ethanol, the costs are therefore competitive. The price of ethanol is very sensitive to electricity costs and fluctuates between 0,56 and 0,74 euros per liter,” said assistant professor Kristian Melin from LUT in Finland.
One of the reasons for the high profitability is that the ethanol yield is much higher than with the traditional bioethanol process based on fermentation from straw or wood. This process produces 1350 to 1410 liters of ethanol, compared to only 200 to 300 liters of ethanol for the traditional process per dry ton of biomass.
Production locations
Part of the study focuses on the variable geographical positioning of production locations, which could allow a certain degree of independence from suppliers to be achieved. “Countries with a high potential for waste wood and green electricity, such as Finland or even Canada, can serve as producers of acetic acid, which is hydrogenated in the final process step to produce ethanol,” explains Prof. Tuomas Koiranen from the LUT.
“In the future, countries like Germany will hopefully have a green electricity mix and be able to carry out the hydrogenation of acetic acid into ethanol on a domestic level. However, Germany does not have the waste wood potential for large-scale gasification of biomass required for the synthesis of acetic acid,” adds Prof. Matthias Gaderer, professor at TUM, adds.
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Source article: innovationorigins.com
