Coal is dirty. Nuclear is dangerous. Wind and solar are intermittent. Trash is a constant, which brings us to landfill gas.
People throw things away. They recycle, sure, but consider all the waste in the world the next time you unpack your groceries. Product packaging alone can fill your trash can after one trip to the supermarket.
Garbage goes into landfills, where it decomposes, and creates methane, a gas much more potent than the whipping boy, carbon dioxide. For years, landfills have gotten rid of this gas, which builds up inside, by flaring it off. Burning it, wasting it.
Landfill gas, in which that methane is harnessed and turned into electricity, has lots of potential. For sure, it’s not perfect, but it has a constant source.
Environmentalists have come around to garbage power. Power Scorecard, a project of the Pace Energy and Climate Center of New York, says landfill gas is pretty green.
And Biofuels Digest notes that even the pope likes waste-to-energy systems.
Why have landfills at all when “waste” can be turned into fuel?
Since we aren’t doing anything else with garbage, methane at least recaptures some energy. If we stopped all recycling, we could instead use thermal and/or catalytic depolymerization to turn trash into biofuel, which could supplant up to 13% of US oil consumption.
Either way, it would green up!
MNN has an interesting piece on a researcher with the Institute for Environmental Management who says advanced methane capture from landfills could power 3 million homes. Includes a link to a pdf.
Landfills are really very underutilized as a resource. While 80% of a product’s resource use is determined in the design phase, acc. to the European Commission, and needs to be addressed equally importantly, recycling waste not only provides energy, but also a wealth of materials esp. metals that can be retrieved and repurposed. For example, US landfills contain about 56 million tons of copper alone, which is 4x the annual global production in 2007!
I heard recently about a start-up company that plans to “mine” copper and other scrap from old landfills. Not sure how true it is. You’d need a pretty big metal detector.
Re: mining landfills, you don’t need a metal detector. There are German companies that use laser induced spectrometry (LIBS) to analyze soil samples for heavy metals. Another technique that looks promising is “electrokinetic cleanup”, using electrodes and a direct current electric field, which attracts and causes the pollutants to migrate to the electrodes, making excavation easier and less expensive. Lots of cool stuff in this clean tech segment.
I was kidding about the metal detector. 🙂 Adi, thanks for the info. Here’s something pretty recent on landfill mining
It all makes me wonder, why didn’t we recycle this stuff in the first place?
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