February 10th, 2010 3:19 PM Eastern

Cleaning the Air One Dumpsite at a Time

 

As smelly and ugly as they may be, landfills are always good sources for stories. This one is especially interesting – a dumpsite being used to help clean the air. Throughout the Bay Area, hundreds of garbage trucks are running on L-N-G: Liquified Natural Gas –  which is produced at the dump in Livermore, California. We visited the new mini-refinery right next door, to see how engineers are closing the loop and “recycling” a waste disposal site into an energy production facility. Every landfill produces the greenhouse gas methane, and while it’s been used to produce electricity for years, now it’s being used to produce fuel. All around the landfill, hundreds of wells, tubes and vacuums are extracting methane from deep underground, where it’s created by decomposing food. The methane is then conveyed a few hundred yards to the LNG plant, where it’s filtered and refined to pipeline quality and turned into liquified natural gas. Another benefit – this process keeps thousands of tons of carbon dioxide from being released into the atmosphere. The L-N-G is then used to fill up garbage trucks: diesel is out, LNG,  which is cheaper and cleaner than diesel. Drivers of the garbage trucks say they appreciate having a fuel that offers the same horsepower, is clean burning, and helps the environment.  While the plant in Livermore isn’t the first of its kind, it is the biggest and most efficient. Every day, it produces 13,000 gallons of liquified natural gas, and will eliminate 30-thousand tons of carbon dioxide every year.  Perhaps the only drawback is the cost: $15-million dollars. But supporters of this process say as technology improves, costs will come down, and more trash heaps will become fuel depots. A second facility is in the works in Southern California, and other large landfills are looking at how they can turn garbage into gas.

Claudia Cowan

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