Pig power: A messy problem becomes a fuel solution

You can thank Hernando de Soto for bacon and pork chops.

The Spanish explorer gets credit for introducing the pig to America, having brought 13 of them to Tampa Bay, Florida, in 1539. By the time of de Soto’s death, three years later, that passel of piggies had grown to more than 700. Yes, pigs grow quickly. They also poop, 24 hours a day, in great quantities.

That manure can be transformed into fuel for vehicles. So even though we’ve let all that pig poop — and cow poop, for that matter — go to waste all these centuries, more of it is being processed to extract methane, the principal component of natural gas.

All over the country, this renewable form of methane is being collected and fed into the nation’s natural-gas pipelines, and then transported to fueling stations to be used as compressed natural gas (CNG) and liquefied natural gas (LNG). The fuel is not only much cheaper than petroleum-based vehicle fuels, it burns cleaner: It contains about 23 percent less in greenhouse-gas emissions than diesel and 30 percent less than gasoline. Capturing all that methane instead of letting it float away from farms is also important, since the gas is more than 20 times worse for the environment than carbon dioxide.

There are some 191 renewable-methane projects on farms in the United States. These farms use anaerobic digesters, which involve storing the manure in tanks or ponds. The fecal matter, as well as food scraps and other farm waste, is broken down into smaller molecules, and the material usually is covered, to help elevate the temperature inside. That allows anaerobic bacteria (which don’t take in oxygen) to go to work on them. Methane is made as a result, and machines vacuum off the gas, cleanse it of impurities (like CO2) and ship it off to be used as fuel.

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A renewable-methane plant outside of Memphis run by Clean Energy Fuels.

 

Livestock is uniquely suited to be a renewable fuel source, because cows and pigs are prolific producers of manure. According to the USDA, dairy cows account for about 80 pounds per day (per 1,000 pounds of animal weight). The equivalent in hogs accounts for 63.1 pounds per day.

At Circle Four Farms near Milford, Utah (about halfway between Salt Lake City and Las Vegas), a million and a half hogs are raised and taken to market each year. It’s the largest pig farm in the western United States, and every day those hogs produce a million gallons of manure.

Three years ago, a Provo firm called Alpental Energy Partners, which finances alternative-energy projects, noticed the potential of the massive farm. (How could one not notice? The odor from the facility can be smelled for miles.) Alpental built anaerobic digesters that turn all that poop into electricity that powers more than 3,000 homes in a town hundreds of miles away.

Such a project could easily provide the same benefits, but for drivers of cars, trucks and SUVs that run on natural gas, which also happens to be a “feedstock” for alcohol fuels that can run in flex-fuel vehicles.

Paul Stephan, managing partner at Alpental, said various incentives, including carbon credits and investment tax credits, which enhanced the revenue stream from the pig project. But those were complicated to secure. “If we didn’t have one of those [revenue] attributes, it would probably be more profitable for us to sell it as transportation fuel,” he said. “I think if I was going to go look at doing another project in the United States off of pig manure and methane, I’d probably sell it as transportation fuel.”

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  1. […] the public is very low. But 17 years wasn’t long enough to give it a chance. Especially with renewable methane (from poop!) just now coming into its […]

  2. […] interesting is the growing success of Redeem, natural gas made from renewable sources. Redeem is the “first commercially available renewable […]

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