Defenders' Experts
Types of Biomass Energy
Biopower
The first major category of bioenergy is “biopower”. It is generated when biomass is burned directly, either alone or along with fossil fuel. For instance, co-firing means adding plant material to a high efficiency burner along with coal, and this significantly reduces sulfur emissions. Methane (which is essentially natural gas) is another biofuel; it is released when biomass decays (e.g., in a natural wetland, landfill or manure lagoon), and is 21 times more potent than carbon dioxide as a greenhouse gas. So capturing methane both prevents methane release and provides a source of energy.
Biobased Products
The second major category of bioenergy is “biobased products;” that is, substituting biomass for petroleum in products like plastics, adhesives, etc. It’s a complex chemical process to make these products, but actually uses less energy than making them out of petroleum. Another benefit is that these products are generally biodegradable.
Biofuels
The third major category of bioenergy is “biofuels,” or liquid fuels for transportation. There are two major categories of biofuels, biodiesel and ethanol. Biodiesel is made from an oilseed, like soy or palm oil, combined with methanol to create an alternative to diesel fuel. Ethanol is made very similar to the process used for beer and wine: fermenting the sugars in a high-carbohydrate crop (like corn or sugar cane). The result can be blended with gasoline at a ratio of up to 10% and run in any vehicle. A select number of cars and trucks are “Flexible Fuel” vehicles can run on a blend of up to 85% ethanol (E85).
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