Landfill methane: What's it worth?Feb 28 - McClatchy-Tribune Regional News - J.D. Walker The Courier-Tribune, Asheboro, N.C
It's hard to get excited about trash. All counties are mandated by the state to manage the disposal of their trash. It's a dirty job, but it's got to be done. What does get some government officials and landfill operators excited is methane. The EPA reports, "Landfill methane is produced when organic materials (such as yard waste, household waste, food waste, and paper) are decomposed by bacteria under anaerobic conditions (i.e., in the absence of oxygen)." And methane may be the new black gold. It can be processed and burned in vehicles modified to use the fuel or it can be burned in generators that create electricity. The BMW plant in Greer, S.C., harvests 60 percent of its energy from the methane gas generated at a nearby landfill. In Florida, Jacksonville Electric Authority recovered more than 17,000 tons of methane from two municipal landfill sites from 2003 to 2005. Landfills are the largest source of U.S. anthropogenic (human-produced) methane emissions, EPA resources report. EPA also reports landfills are the third largest human-related source of methane in the U.S., accounting for 17 percent of all methane emissions in 2009. But landfills don't hold a candle to cattle. EPA researchers report, globally, ruminant livestock produces about 80 million metric tons of methane annually, accounting for about 28 produce of global methane emissions from human-related activities. In the U.S., cattle emit about 5.5 million metric tons of methane per year into the atmosphere, accounting for 20 percent of U.S. methane emissions. The amount of methane that could be generated at a regional landfill in Randolph County can be hard to determine. It all depends on the amount of waste received, waste composition, moisture content, landfill design, operating practices and climate. One bio-fuel website estimates, a ton of garbage will make roughly 40 cubic meters of methane a year. The proposed regional landfill in Randolph County would be expected to take in 1,500-2,000 tons of trash a day. It's a little easier to calculate cattle methane production. The N.C. Department of Agriculture and Consumer Services recorded 80,000 cattle in Randolph County in January 2012. An adult cow can generate about 100 pounds of manure a day. One pound of cow manure can produce about one cubic foot of gas. About 60 percent of that gas is estimated to be usable methane. One bio-fuel source estimates the manure produced by one cow in one year can produce enough methane to replace more than 53 gallons of gasoline. So, 80,000 cattle should be able to make enough methane to replace about 4.2 million gallons of gas per year. That would be enough gas to fuel one vehicle per household in Randolph for a month (estimating one tank of gas a week). http://www.energycentral.com/functional/news/news_detail.cfm?did=27760254 |