State-of-the-art plant makes trash vanish into thin air

By Dan Miller
Staff Writer

It seems like something out of The Jetsons: plasma, vaporization, temperatures nearly as hot as the surface of the sun.

These are all parts of St. Lucie County, Fla.’s new plan to deal with its trash.

In a move that would create the first facility of its kind in the United States (and the largest in the world), the county is planning to construct a plant that would vaporize trash and create energy through technology called plasma gasification.

"It seems like a very promising and exciting future for waste management in the United States," said Assistant Solid Waste Director Ron Roberts.

Plasma gasification uses electricity and high-pressure air to create plasma (a very hot, gas-like state of matter) with temperatures exceeding 5,500 degrees Celsius (9,932 degrees Fahrenheit). As solid waste is added to the plasma, the molecules break apart at their elemental state, creating a synthetic gas, which in turn powers a turbine to create electricity.

According to Roberts, the county began exploring new ways to deal with its trash as a result of its rapid growth. St. Lucie County is the 13th fastest growing county in the country, according to the U.S. Census Bureau, and Roberts said the life expectancy of its landfill is expected to shrink from 40 years to 25 years.

St. Lucie County issued a request for qualifications for organizations that could finance, own and operate a facility in the area and selected the Georgia-based company Geoplasma, LLC to build the plant.

"The county considered several options before settling on plasma gasification, including fossil fuel gasification, anaerobic digestion, fermentation, incineration, hydrolysis, chemical conversion and improved landfilling methods.

"Plasma arc gasification was the one that leaves nothing to be landfilled, is proven, is environmentally superior, generates much more energy than it requires and is economically viable," Roberts said.

"The board is really excited about the idea," said St. Lucie County Commissioner Chris Craft. "We’re approaching it with the proper amount of skepticism to make sure we’re not so eager we’re overlooking things."

Since the plant would produce three times the energy it needs to operate, it would run on the energy it produces and sell the remainder. The process also creates a hard, obsidian-like material which the county can sell or use to pave roads.

"It’s going to have a great environmental impact," Roberts said of the 33-acre baling and recycling landfill. "When we start mining the waste, it (the landfill site) can be used as an industrial park instead of something that needs to be monitored."

One of the best parts for St. Lucie County taxpayers is that this effort won’t cost them a dime. Geoplasma and its finance team partners will foot the bill for the project. Roberts indicated that he wanted to come up with a solution to the solid waste problem that would not result in an increase in tipping fees.

Roberts estimates that the plant will be finished within 24 to 30 months. Geoplasma estimates that it will take 15 to 18 years to dispose of all the waste in the landfill.

NASA originally developed plasma arc technology in the 1960s as a way of testing heat shield materials that protect spacecraft upon re-entry to the earth’s atmosphere. The technology has a variety of uses (General Motors has been using it since 1989 as a way to melt iron), including the disposal of municipal solid waste.

Currently, the only place that is running a similar operation is in Japan, where Hitachi Metals Ltd. has been operating two commercial plasma arc facilities to handle hundreds of tons of solid waste and ash every day. The facilities have also been providing electricity to the local power grid.

Officials from St. Lucie County visited Japan four months ago to tour the plasma arc facilities. The Japanese facility is one-tenth the size of the proposed Florida plant and processes about 300 tons of waste per day.

"The folks were extremely gracious; they welcomed us with open arms. I was quite impressed," Craft said.

Plasma gasification produces no harmful by-products and any gaseous waste matter will be captured for treatment, Geoplasma says. The company also claims that all the emissions associated with the process fall "well below" EPA standards.

"Anybody that says this is not environmentally friendly, [I’d like them to] provide us real data that the plant in Japan has not been doing what they have been doing for four years," Roberts said. "If there’s a better alternative, we haven’t found it in the 26 months we’ve been looking."