You may have heard it called waste-to-energy, energy-from-waste, or energy recovery. Used interchangeably, they all describe the waste management strategy of using non-recyclable materials and converting them into useable heat, electric or fuel through combustion. The waste-to-energy process generates renewable energy and off-sets the need to create energy from fossil sources. It also works to reduce carbon emissions and reduce methane gas from landfills.
Waste Management Hierarchy
It is important to understand the EPA’s waste management hierarchy, the preferable ways of handling industrial and organic waste, and where the energy recovery process falls in the hierarchy. After overall waste reduction, which is the most beneficial option, recycling is the preferred method of controlling waste. However, some materials cannot be recycled and that is where energy recovery steps come into play, to avoid the least desirable outcome, which is disposal into a landfill.
Reduction & Reuse
This is the most environmentally preferred waste management method. This includes the reduction of waste at the production source, reducing packaging, buying materials in bulk, or redesigning products to include fewer raw materials.
Recycling & Composting
We are all familiar with the recycling process, which involves collecting and sorting waste to isolate recyclable materials, which can then be broken down and processed into new raw materials and remanufactured. In a similar process, composting breaks down organic waste materials to produce fertilizer or soil amendment. Thirty-four percent of American’s municipal solid waste is recycled or composted.
This waste management strategy is employed to prevent non-recyclable materials from ending up in landfills. The waste is combusted and used to create new sources of renewable energy. Energy recovery handles 12% of America’s municipal waste.
Treatment & Disposal
Treatment and disposal is the least sustainable outcome of waste management. While various treatment methods work to reduce the volume of waste and toxicity in waste, 54% of municipal waste is deposited into landfills each year.
How Waste-to-Energy Has Changed Over the Years
The combustion used in the waste-to-energy process is often associated with trash incinerators used in past decades. But today’s energy recovery process has advanced and evolved. In the past, the creation of energy was not a priority and trash was only burned to reduce volume.
Energy-from-waste methods continue to reduce the volume of waste, by nearly 90%. (The remaining 10% of waste used in energy recovery is now ash, which is deposited into local landfills.) But today’s processing plants are also creating renewable energy, which can lessen our dependence on coal or oil in the creation of energy. According to Municipal Solid Waste in the US: Facts and Figures, in 2012 the United States combusted about 29 million tons of municipal waste (12% of total waste) for energy recovery. The 86 processing facilities across the country have the capacity to turn that 29 million tons of waste into 2,720 megawatts of power each year.
A few more outstanding statistics from the Energy Recovery Council:
- Waste-to-energy plants keep 90,000 tons of waste out of landfills each day
- Seventeen billion kilowatts of electricity are produced each year
- This can meet the electricity needs of nearly two million homes
- It would take 7.8 million tons of coal to produce the same amount of electricity
Also changing is the amount of air pollution created as a result of this waste reduction strategy. After the passing of the Clean Air Act, approximately $1 billion was invested to upgrade air quality control systems and quality control devices at U.S. waste-to-energy facilities. This led to a reduction in emissions to levels far below state and federal standards. The EPA has since concluded that “waste-to-energy generates electricity with less environmental impact than almost any other source of electricity.”
As technology develops further, the energy recovery process can be broadened further to include non-recyclable plastic materials, to create plastics-to-fuel technology. Using much of the same methods, non-recyclable plastics are heated, melted, and vaporized into gas that can be used in the production of fuels for home heating, diesel, or gasoline.
The Fight Against Global Warming
Waste-to-energy is playing a large role in the fight against global warming and overall climate change. As waste in a landfill breaks down, it produces methane gas, one of the more potent greenhouse gases affecting climate change. By finding alternative uses for waste, we can decrease the level of methane gases produced.
The energy recovery process creates carbon dioxide emissions (another greenhouse gas), however, when we compare it to the amount of CO2 released when creating the same amount of energy using coal or oil, energy recovery has a clear advantage. Add to that the amount methane gas avoided by not disposing the waste in a landfill, and you’ll see that the process avoids nearly one ton of greenhouse gas for every one ton of waste handled.
ERC provides waste-to-energy services for a number of industries in an effort to prevent waste disposal in local landfills. If you have any additional questions or concerns about this energy recovery process, please contact us!
photo credit: http://www.flickr.com/photos/10688882@N00/14507191708