Could poop power your home some day?
Well, Sanford, Fla., and MaxWest Environmental Systems Inc. of Texas have teamed up to convert the city's stream of wastewater sludge into renewable energy.
The goal is to take everything the good people of Sanford send down their toilets and sinks and turn it into energy, instead of sending it to landfills.
The city dries 30 tons of sludge daily with a natural gas-powered dryer and then hauls the biosolids off-site for disposal. But under a new $3.5 million gasification system, the sludge will be converted into thermal energy, which will replace the natural gas to power the dryer.
The new system is not only greener, it could also save the city $9 to $14 million for the life of the 20-year contract, according to MaxWest.
"There are a variety of disposal systems. The traditional ones have been to dump it ... or put it in a landfill," said Bill Baker, vice president of marketing for Houston-based MaxWest. "We don't know of any other gasification system in North America operating on sludge."
In two years, the company hopes the same technology used in a different part of the state will create enough power to supply the needs for 1,500 homes.
"The primary driver is to get rid of a tremendous amount of horse muck -- manure, straw and wood chips -- used in the thoroughbred industry," Baker said of the project in Florida's Ocala County.
Using the same gasification system, the company intends to produce about 10 megawatts of power, which will be sold to the local power grid.
Allen Hershkowitz, a senior scientist with the New York City-based Natural Resources Defense Council, said that although there have been attempts to gasify waste and convert it to energy, they've generally been smaller-scale research and development projects.
"We don't have a lot of experience with the gasification of biosolids for energy recovery," he said.
Although he was not familiar with the details of the Sanford project, he said it seems to be an innovative approach as long as toxic prevention controls are also in place.
A range of pollutants, such as copper, cadmium and chromium, could result from the gasification process, he said. But with proper controls and oversight, they could be contained.
MaxWest's Baker said the gasification facility uses industry-standard clean technology to capture toxins released during the process. He also said the system is engineered to mitigate the polluting emissions and that many chemicals are destroyed by the sustained time at high temperatures.
"This is a technology that is needed," scientist Hershkowitz said. "They do have some energy value and if we could recover energy from it and also reduce the mobilization of pollutants, that might be associated that would be a good thing."
Although MaxWest's gasification system is new to the United States, many others around the country, and around the world, are experimenting with poop-to-power projects. Here are four examples.
Phil Zahreddine, a branch chief with the Environmental Protection Agency, said that although gasification is not common in the United States, it could prove to be one more way to cut back on fossil fuel.