Portland, Ore. -- Environmental engineers in Indiana are engaged in a pilot program to build energy-recycling facilities that they claim will significantly lessen U.S. dependence on fossil fuels like gas and petroleum. The program aims to build a $12.5 million industrial waste conversion center, a $5.5 million hog waste conversion facility (including a 2.5-mile pipeline) and a shared methane-to-electricity conversion site. The buildings are due to be operational by 2008.
The facilities will be modeled on similar efforts in Europe, where waste is already being converted to methane gas.
"To put it in perspective, adding a biorefinery that produces methane fuel in an industrial plant that has a rich organic waste stream can cut back their need for natural gas by 10 to 30 percent," said Loring (Larry) Nies, a Purdue University engineer specializing in the biotransformation of organic pollutants.
"Our ultimate goal is to demonstrate how communities can work together to take advantage of the biological resources we already have," said Nies. "And our second objective is to get the word out so more communities start energy-saving projects--we are a little behind in the U.S. compared to Europe because their energy prices are higher."
The United States expends vast energy resources treating waste water, Nies said. Plants throw energy away because they use electricity for power when they should harvest energy in the waste stream to produce electricity instead.
"These technologies have already been proven out; they just haven't been widely applied ," said Nies. His students found "we could potentially . . . save approximately 6 percent of our natural gas."
With the program engineers predicting an energy savings of up to 6 percent statewide, the $18 million pilot program aims to demonstrate how converting waste to methane-powered electricity generators can turn into big savings if the program is adopted across the nation.
Now, "5 or 6 percent doesn't sound like much, but realistically this is how we are going to solve our energy problems," said Nies. "The solution is not one big silver bullet that replaces petroleum, but little chunks at a time that add up--5 percent here, 6 percent there, 3 percent somewhere else, and pretty soon you're talking about a 30 or 40 percent savings. We want to spread the awareness that we can solve our energy crisis now--2 to 5 percent at a time."
Nies' speciality is the anaerobic digestion of organic waste materials that range from banana peels to waste water. Anything organic can be attacked by bacteria in closed vats to produce methane. The methane is then burned directly in boilers or in combustion turbines that drive the electricity generators.
"We are encouraging local industry to use methane directly in their facility first--to fire their own in-house boilers that in turn can drive their own internal in-plant processes and reduce their dependence on natural gas," said Nies.
Today waste is treated in sewage plants where open-air bacteria digest it in cesspools, and the plant is powered by electrical pumps. Indiana's engineers propose a different technology.
"Instead of expending energy in aerobic waste treatment plants [open cesspools], the waste is processed without oxygen using anaerobic microorganisms to break down the waste and release methane gas," said Nies. "You have to have a closed vessel, of course, so that you can collect the methane gas."