> Power Generation from Recovered Methane
>Don Augenstein is technical director/VP of I E M, Inc., a
>nonprofit participating in environmental research on the climate
>effects of solid waste, renewable energy, and related issues.
>Don will discuss a new approach for solid waste landfill management
>called "controlled landfilling", which is receiving increasing
>attention and encouragement from federal (EPA, etc.) and California
>regulatory agencies and also from the private and public waste
>management sector. Don will describe the encouraging performance
>of a 4 year project in Yolo County utilizing the controlled
>landfill approach to control and speed methane generation, increase
>methane recovery for energy and reduce fugitive emissions to the
Don Augenstein began his talk by explaining that one of the large sources of methane in our atmosphere is landfills, from which millions of tones of the stuff are exhaled every year. The problem is that under normal landfill conditions, the stuff just bleeds into the atmosphere slowly, sometimes taking 50 years to finish the decomposing process on the carbon based contents like lawn clippings, paper, and food waste.
Don Augenstein has spent many years in the waste management industry. He showed us research results he had come up with in the 1970s that conclusively proved that by adding water to a landfill it was possible to speed up the decomposition process, so that the process could be completed in 10 years or so. In addition to adding water, he described methods of capturing the "swamp gas" that comes off (about half of it is methane), which can then be used to run engines and generate electricity.
Many of the problems he experienced getting a trial site going were regulatory in nature. The regulations that govern landfill design are a patchwork of competing ideas, many with poorly thought out relationships with each other. For example, it is illegal to put liquids in a landfill, so it was necessary to find a loophole that they could sneak water through. With the help of the California Waste Management Board they were able to do that.
The demonstration site in Yolo County has two landfill cells, each 100 ft by 100 ft by 40 ft deep. One cell has the water added process going, and the other is monitored and tapped for methane capture the same way, but not wet. He showed charts over two years for both, and clearly much more decomposition was going on in the wet cell. In addition, the internal temperature of that cell was higher, indicating that composting was happening. He showed pictures of the two cells, and the ground level of the water added one was clearly falling relative to the other, indicating that another advantage of this process was reduced landfill volume over time.
He concluded his talk by pointing out that capturing landfill emissions could reduce the greenhouse gas emissions of the human race by as much as 5 to 7 percent. When you consider that the burning of this gas could replace natural gas or other fossil fuels, even greater net savings per year could result. Augenstein feels that there is no other step we can as easily take that will help us as much to get our house in order on the Climate Change issue.