How Are Waste Products Turned Into Energy Sources?

There are several common ways in which we can turn waste into a source of energy. Waste cooking oil can be turned into biodiesel to run our vehicles on. Large amounts of methane produced by landfills can be collected and harnessed to run factories. Ethanol can be produced from the wasted parts of plants after harvest. These are all relatively new technologies, and research is continuing to progress to find out which are the most efficient sources of energy, as well as the cheapest to mass-produce.

Biodiesel

• Biodiesel fuel is a long-chain fatty acid that can be produced from cooking oil after it has been used. Many restaurants must pay to get rid of the waste oil they use, and will give it away to anyone interested in making biodiesel. The fuel is produced by blending the cooking oil with lye and methanol or ethanol. This separates the glycerine molecules from the fatty acids in the vegetable fat, allowing it to be used as fuel. It can be used in any diesel engine, or an engine can be converted to run on straight cooking oil or biodiesel.

Methane from Landfills

• Landfills are the second largest human produced source of methane in the United States, according to the Environmental Protection Agency. This gas is produced by decomposing solid waste over time. There is a program called the Landfill Methane Outreach Program in place through the U.S. EPA to collect the methane that escapes from landfills and use it to power factories, vehicles, and even homes. A series of wells and vacuums direct the gas to a location that it can be converted. This keeps the methane odors down around the landfill and keeps the greenhouse gas out of the atmosphere so it cannot contribute to global warming.

Cellulosic Ethanol

• Ethanol was focused on in the past for a short time as a great alternative fuel. It was soon realized that the process was using up a great deal of food, mainly corn, to produce it. They have more recently been testing using the cellulose of the plant, or the parts not digestible by humans. This was going to waste anyway. The process of converting cellulose requires one extra step than regular ethanol, because it does not already have a lot of starch. It starts with lignins that must be converted to starch. Then, the starch is converted to sugar, which is fermented into ethanol. As ethanol, it can be used to power vehicles.

Benefits

• Using energy sources from waste products can greatly reduce our impact on global warming if they become used more commonly soon. Each bit of waste that is recycled into energy does not go into the atmosphere or a landfill, leaving us more space and cleaner air. This type of energy could also help reduce dependence on petroleum-based fuels.

Considerations

• Not all of the waste is captured as energy in any of these processes. More waste is created by turning the original waste into energy. It is still important to recycle and to reduce the amount of waste we create in order to live a sustainable lifestyle.