Ethanol producers find a solution to their energy problem in an unusual place: cattle manure.
Making ethanol takes more than corn and enzymes. It requires a lot of energy as well. Ethanol manufacturers spend about $8 million a year on the natural gas needed to produce the 25 million gallons of fuel they turn out.
And while the price of natural-gas has been rising, the price of distillers grains–a protein-rich ethanol byproduct that manufacturers sell as feed for cattle, pigs and other animals–has been shrinking. That’s because, as the industry produces more ethanol, it also produces more distillers grains, while the number of cows and pigs eating those grains remains stable.
Companies like Panda Ethanol and E3 Biofuels are working to solve both problems, with so-called “closed-loop” systems. Their solution depends on cows.
Here’s how it works. The ethanol process yields fuel and cattle feed. Cattle eat the feed and “yield” manure. The companies use the manure to make methane, which can power their plants. Everything is used, nothing wasted. In other words, a closed loop.
Panda and E3 say their “brown power” will save them plenty of green and make them more energy efficient.
Panda is building four manure-powered ethanol facilities, with its first–a 105-million-gallon-a-year plant in Hereford, Texas–expected to open in the fourth quarter of 2007. The company plans to gasify the manure, essentially burning it, to generate steam, which it will use to fuel its ethanol-manufacturing process.
E3 Biofuels is taking a different approach. Its first plant–a 25-million-gallon-a-year facility in Mead, Nebraska, expected to open in spring 2006–will use an anaerobic digester. It works with the bacteria commonly used in septic tanks to turn manure into methane. E3 will use the methane to power its plant.
Of course, the process isn’t hassle-free. The companies will have to gather and transport their manure and be sure to meet new EPA standards for its handling. They’ll have to prove they’re cleaning it without pollution runoff and without causing manure-borne illnesses in other animals that might end up eating it.
But if the companies can meet the challenges as they expect, you can count on more ethanol facilities to embrace cow power. — InPipeline Editors
1 response so far ↓
1 DVMitch // Apr 19, 2007 at 8:48 am
E3 will not have to gather and transport the cow manure as their ethanol plant is built adjacent to a 30,000 head cattle feeding operation. The cattle are confined in feed barns with slatted floors so that the manure can be collected from pits below the slatted floors and moved to the nearby anerobic digesters. The methane produced by the digesters is piped to the ethanol production facility, a few hundred feet at most.
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