BMW of North America will use California dairy manure to generate green electricity. The company announced this the day before, presenting its new partner – the Bar 20 Dairy farm from the California town of Kerman. On the territory of the farm there is a new generation bioreactor capable of capturing the methane emitted by manure and converting it into clean energy without burning.
The construction of the bioreactor, in this case anaerobic (without oxygen supply), was carried out by California Bioenergy. The principle of its operation is simple and is based on the process of methane fermentation, which in a simplified form looks like this: the biomass entering the reactor under the influence of bacteria is first converted into methane, water and carbon dioxide; then the biogas is filtered and transferred to the fuel cells, where pure hydrogen is extracted from it by steam reforming. In the last step, hydrogen is oxidized at the anode, which generates current.
It cannot be said that this method is completely harmless to the environment, since steam reforming produces a small amount of greenhouse gases (but much less than when burning hydrocarbons). However, by capturing the methane gas and converting it into clean electricity, BMW believes it will offset 100 percent of its carbon footprint. In addition, the Bar 20 Dairy plant produces twice as much electricity as conventional generators for the same gas volume. Well, the material digested in the bioreactor can be further used as fertilizer.
Reduced methane emissions, combined with green electricity generation, are estimated to result in a reduction in carbon dioxide emissions equivalent to charging more than 17,000 EVs a year. The project is primarily aimed at reducing dependence on fossil fuels, but will also contribute to improving air quality in Northern and Central California, BMW believes.