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Business, Cities, Energy, Municipal, Sustainability

Energy and economic value of plastics and municipal solid wastes

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Plastic trash is a potential — and plentiful — fuel source, but up to the present many regions of the United States have been reluctant to adopt waste-to-energy technologies. Among the reasons are the availability of relatively cheap land for trash disposal, recyclers who viewed such programs as potential threats, and resistance by local homeowners.

A 2011 study by Columbia University’s Earth Engineering Center for the American Chemistry Council, “Energy and Economic Value of Non-recycled Plastics (NRP) and Municipal Solid Wastes (MSW) that are Currently Landfilled in the Fifty States” (PDF), attempts to calculate the energy contained in discarded materials and its economic value. In their study, the researchers first calculate the amount of plastic waste in the United States in 2008 based on EPA data and the center’s own survey, then use this information to apportion the amount of waste and lost “energy value” per state.

Key study findings include:

  • Overall U.S. post-consumer plastic waste for 2008 was estimated at 33.6 million tons; 2.2 million tons (6.5%) were recycled and 2.6 million tons (7.7%) were burned for energy; 28.9 million tons, or 85.5%, were discarded in landfills.
  • The United States currently has the capacity to convert just 10% of the postrecycled municipal solid wastes (27 million tons) to energy.
  • Connecticut, Massachusetts, Hawaii, Virginia and Minnesota were rated the best at sustainable plastic waste management, measured by utilization of post-consumer plastic and tons of waste in landfills. Alaska, New Mexico, Montana, Oklahoma and Mississippi were rated the worst.
  • The potential energy contained in the 28.9 tons of post-consumer plastics deposited in landfills in 2008 equals the amount of BTUs  in 36.7 million tons of coal, 139 million barrels of oil, or 783 billion cubic feet of natural gas.
  • If all the discarded plastic currently landfilled were separated and recycled, they would produce an estimated 87 million barrels of oil per year (3.6 billion gallons). This is enough to run six million cars for one year or generate 52 million MWh of electricity, supplying 5.2 million households.”
  • Replacing 25% of the current U.S. landfills with new waste-to-energy capacity would result in the annual production of about 41 million MWh of electricity, enough for 4.1 million households.

The researchers recommend upgrading existing waste-to-energy plants to handle more plastic waste materials. This will result in additional energy recovery as well as a reduction of the greenhouse gas emissions associated with landfills.

Tags: technology, greenhouse gases, recycling

    Writer: | Last updated: November 17, 2011

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    Analysis assignments

    Read the Columbia University study titled "Energy and Economic Value of Non-recycled plastics (NRP) and Municipal Solid Wastes (MSW) That are Currently Landfilled in the Fifty States."

    1. Summarize the study in fewer than 40 words.
    2. Express the study's key term(s) in language a lay audience can understand.
    3. Evaluate the study's limitations. (For example: Do the results conflict with those of other reliable studies? Are there weaknesses in the study's data or research design?)

    Read the study-related CNET article titled "U.S. missing out on energy from trash, study says."

    1. Reporter's use of the study: Evaluate what the reporter chose to include and exclude from the study. Would the audience have acquired a clear understanding of the study's findings and limits from this article?
    2. Reporter's use of other material: Assess the material in the article that is not derived from the study. For example, does the reporter place the study in the context of other research and to what effect? Does the reporter include reactions to the study from other researchers or interested parties (e.g., political groups business leaders, or community members) and are their credentials or possible biases made clear?

    Newswriting assignments

    1. Write a lead (or headline or nut graph) based on the study.
    2. Spend 60 minutes exploring the issue by accessing sources of information other than the study. Write a lead (or headline or nut graph) based on the study but informed by the new information. Does the new information significantly change what one would write based on the study alone?
    3. Interview two sources with a stake in or knowledge of the issue. Be prepared to provide them with a short summary of the study in order to get their response to it. Write a 400-word article about the study incorporating material from the interviews.
    4. Spend additional time exploring the issue and then write a 1,200-word background article, focusing on major aspects of the issue.