U.S. missing out on energy from trash, study says
by Candace Lombardi October 12, 2011 10:40 AM PDT
Columbia University researchers assert that tech breakthroughs in recent years now make sending trash to landfills a waste of energy.
While recycling and energy recovery from plastics is on the rise, about 86 percent of used plastics are still sent to landfills. It's a big waste considering its energy potential, according to the 33-page report, "Energy and Economic Value of Non-recycled Plastics and Municipal Solid Wastes that are Currently Landfilled in Fifty States" (PDF).
Agilyx plant that converts plastics into a synthetic crude oil that can then be sent to a refinery.
(Credit: Agilyx)
About 28.8 million tons of non-recycled plastics were sent to landfills in 2008, the energy potential equivalent of 36.7 million tons of coal or 139 million barrels of oil, said the report.
The study, co-authored by researchers at the university's Earth Engineering Center, determined that if the U.S. took all the non-recycled plastic currently sent to U.S. landfills each year and instead sent that trash to a waste-to-energy (WTE) power plant, it would produce enough electricity for 5.2 million U.S. homes annually.
If that plastic was separated by type, enough petroleum-based plastics could be recovered and sent to a pyrolysis conversion facility, a plant that converts non-recycled plastics into fuel oil, to produce 3.6 billion gallons of oil. That's enough to power 6 million cars for a year.
The comprehensive study also broke down how much waste is being recycled or reused and how much is sent to landfills in each state.
Some states are taking advantage of the latest waste management technology. Connecticut, for example, has the best record for this, achieving a recovery of 65 percent on plastic waste when including both recycling and waste-to-energy conversion. Other states with the best record for capitalizing on the energy of waste include (in order) Massachusetts, Hawaii, Maine, Virginia, Minnesota, New Jersey, New York, Maryland, and Pennsylvania.
The energy potential is even greater when you expand beyond plastic.
"Hypothetically, if 100 percent of the landfilled municipal solid wastes were diverted from landfills to new waste-to-energy power plants, they would reduce coal consumption by 108 million tons and produce 162 million MWh of electricity, enough to power 16.2 million households for one year," said the report.
The report's assertion that the tech for this is already available is evident.
Oregon-based Agilyx raised a lot of money and attention after it announced it had developed an efficient process for converting plastics into synthetic oil. Even more notable is that Waste Management, one of the largest garbage management companies in the U.S., was recently estimated to be producing more electricity annually than the entire solar industry. And it's not all just incineration. Among its many trash-to-treasure endeavors in recent years, the company has begun producing liquefied natural gas from landfill gas, and converting organic waste into gardening products or using it to make biogas via anaerobic digestion.
Candace Lombardi Candace Lombardi, a freelance journalist based in the Boston area, focuses on the evolution of green and otherwise cutting-edge technologies, from robots to cars to scientific innovation. She is a member of the CNET Blog Network and is not a current employee of CNET.
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