In January, the Sacramento, Calif., City Council unanimously rejected a proposal for a $200 million plasma arc gasification facility.
"It was clear that the mayor and city council thought this wasn't the best time to break new ground," says Jim Rinehart, the city's economic development manager and lead staff member for the city on the project. "The city just didn't get enough detail on the proposal."
Plasma arc gasification technology uses plasma arcs to convert waste directly into a gas and break the material down into basic elements. The process produces a synthesis gas that can be converted into fuel, an inert slag that can be used for road construction and steam that can be used to produce electricity.
Rinehart says Sacramento feels as much pressure from California's looming $41 billion budget crisis as any other city in the state. Because of that pressure, he adds, the city was less likely to take such a risk after receiving mixed reviews of the proposal's finances.
In 2007, Sacramento shipped an average of 402 tons of trash each day to landfills in Nevada, and the city's diversion rate was 46 percent. The city was looking for a way to continue diverting waste from its landfills, save the approximately $8 million it spends each year hauling waste to Nevada and possibly create revenue from selling the residuals from the plasma arc gasification process.
After the city submitted a request for qualifications in August 2007, Sacramento-based United States Science and Technology (USST) was selected to submit a proposal. The company patterned its plans after a similar privately owned facility in Utashania, Japan that processes roughly 280 tons of garbage each day. USST proposed to build and operate the facility at no cost to the city, based on revenue it projected from the sale of synthesis gas, slag and electricity produced from the steam.
The city hired Concord, Calif.-based Advanced Energy Strategies (AES), an energy-consulting firm, to review the proposal. Dean Tibbs, a Ph.D. economist and president of AES, says he disagreed with some of the assumptions used by USST to calculate the project's cost, particularly the assumed $400 per ton market value of the slag residual.
"There may have been a better way to reduce the fuel supply and size of the project in order to reduce its cost," Tibbs says. He believes in the technology itself, but just does not think this particular proposal was economically feasible at the current time, he adds.
"I still don't consider the project dead," says David Prinzing, vice president and chief engineer for USST. "I still look forward to working with the project and the city of Sacramento."
Rinehart also says the possibility of the city giving plasma arc gasification another try remains open, but that both the new proposal and the city's economic situation would have to be right. "We all learned that wastes can be bought from us instead of paying to take it away," he says. "Of course that's if the technology is right."