High-grade charcoal is used in laboratory and industrial chemical applications. Co-firing is currently well developed in the USA but also in a stage of research and development as electricity companies examine the effect of the addition of wood to the coal, in terms of specific power plant performance and potential problems. It is hoped that co-firing will become economically viable in the future, allowing coal power stations to produce a small portion of renewable energy. The best-known feedstock for ethanol production is sugar cane, but other materials can be used, including wheat and other cereals, sugar beet, jerusalem artichoke, and wood. Similarly, cellulose materials, such as wood and straw, are readily available but require expensive preparation.
Ethanol is produced by a process known as fermentation.
Typically, sugar is extracted from the biomass crop by crushing, mixing with water and yeast, and then kept warm in large tanks called fermenters. The yeast breaks down the sugar and converts it to ethanol. Brazil has a successful, industrial-scale ethanol project, which produces ethanol from sugar cane for blending with petrol. Some engine adaptations are required for full petrol substitution. The remaining crop residues such as straw or bagasse can used to supply the external heat required for the process.