Producing ethanol on the basis of economic competitiveness and technical efficiency

According to the latest assessment report of the Intergovernmental Panel on Climate Change, to limit the consequences of climate change, we need to significantly reduce carbon dioxide emissions. Using renewable energy such as waste wood and straw to produce fuel or use renewable electricity will be a way to reduce carbon emissions in the transport sector.

In this case, cutting materials in the forestry sector are used together with hydrogen. Hydrogen is produced by using electricity to separate water into hydrogen and oxygen – in other words, electrolytic water. In the future, this will allow excess electricity to be used to produce ethanol.

“The whole process is mainly composed of sub processes with mature technology. However, the composition of the process steps and the last step – acetic acid hydrogenation to produce ethanol – are new,” explained Daniel Kl ü h, a doctoral student who teaches renewable energy systems at the Toronto University of Technology’s Straubin campus.

The cost of using this new production method to produce ethanol is competitive

The researchers also evaluated the economic feasibility. “The prices we calculated are based on the assumptions of raw materials and energy. We do not use any current market prices. Our chemical system component prices are calculated based on 2020,” explained Kl ü h. In the model, the minimum cost of ethanol is 0.65 euros per liter, the cost of biomass is 20 euros per megawatt hour, the cost of electricity is 45 euros per megawatt hour, and the annual ethanol output is about 42000 tons.

“Therefore, the cost is competitive among the current lignocellulosic ethanol production options. The price of ethanol is very sensitive to the cost of electricity, which fluctuates between 0.56 and 0.74 euros per liter,” explained Christian Merlin, assistant professor of Finland LUT. One reason for the high profit margin is that compared with the traditional straw or wood fermentation bioethanol process, the ethanol yield is much higher. Compared with the traditional process, which can only produce 200 to 300 liters of ethanol per dry ton of biomass, this process can produce 1350 to 1410 liters of ethanol.