The average American produces about 1,600 pounds of waste per year. Currently, the U.S. burns only 14 percent of its waste.
Bioenergies
Scientists are constantly working to find new ways to create clean, sustainable and renewable energy. One of the more recent advances is bioenergy. Bioenergy is renewable energy made from any organic material from plants or animals. Sources of bioenergy are called "biomass." Biomass consists of three main segments: wood, solid waste, and alcohol fuels.
Biomass is a renewable resource that is more evenly distributed over the Earth's surface than other energy sources, and they may be extracted using environmentally friendly technologies. Today, biomass resources are used to generate electricity, and to produce liquid transportation fuels, such as ethanol and biodiesel.
Harnessing the heat
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This wood burning biomass facility in Germany |
The most common form of biomass is wood. Many of us still burn wood as a source for heat in our homes. Power plants that burn wood to produce electricity are using the same techniques that manufacturing plants around the world have used for centuries. These plants burn wood, wood scraps, wood chips or sawdust to produce steam and therefore create electricity.
Some bioenergy power plants also use solid waste to produce electricity. Waste that comes from plant or animal products is biomass. Food scraps, lawn clippings, and leaves are all examples of biomass trash. Solid waste can be a source of energy by either burning it in waste-to-energy plants, or by capturing biogas. In waste-to-energy plants, trash is burned to produce steam that can be used either to heat buildings or to generate electricity.
Power through ‘digestion’
In landfills, biomass rots and releases methane gas, also called biogas or landfill gas. Some landfills have a system that collects the methane gas so that it can be used as a fuel source. Some dairy farmers collect biogas from tanks called "digesters" where they put all of the muck and manure from their barns. Inside the digester, methane gas is separated from the liquid and solid waste. The methane gas can then be used to generate electricity.
Putting our waste to good use
According to the Environmental Protection Agency (EPA), the average American produces about 1,600 pounds of waste per year. Currently, the U.S. burns only 14 percent of its waste, leaving the remainder of it in landfills. However, there is energy in our waste. This energy can be reached by burning it. Burning waste seems like a great idea, but many people are concerned about the smells and substances that could be released when waste is burned. Therefore, the EPA applies strict environmental rules to waste-to-energy plants. The EPA requires waste-to-energy plants to use anti-pollution devices, including scrubbers, fabric filters, and electrostatic precipitators. These technologies greatly reduce any foul smells or pollutants from entering the air.
Biofuels can drive our lives
Many people have heard of biofuels, most notably ethanol and biodiesel. These fuels are made from renewable biomass materials and are usually blended with traditional fuels to make them usable in passenger vehicles.
Ethanol is an alcohol fuel made from the sugars found in grains, such as corn and wheat. Scientists are working on cheaper ways to make ethanol by using all parts of plants and trees. Most of the ethanol used in the United States today is distilled from corn.
Biodiesel is a safe, biodegradable, renewable fuel that is made with vegetable oils, fats, or greases - such as recycled restaurant grease. Biodiesel fuels can be used in diesel engines without any necessary modifications.
A part of the Carbon Cycle
Since most biomass is created by plants and animals; it is therefore part of the carbon cycle. Carbon from the atmosphere is absorbed by plants through photosynthesis. Once the plant dies or is burned, it releases the carbon which returns to the atmosphere as carbon dioxide (CO2). This happens over a relatively short timescale and plant matter used as a fuel can be constantly replaced by planting for new growth. Biomass is renewable because waste piles up rapidly and we can grow more trees and crops.