Betting on a hot market for syngas

Turning scrap metal and debris into energy may help U.S. ease its reliance on oil

By Robert Gavin Globe Staff / August 25, 2008

NEW BEDFORD – Take a rusting, hulking pile of scrap metal, add a few tons of construction debris, and what do you get?

In the case of Ze-gen Inc., a new source of energy.

Ze-gen, founded four years ago, is using the unappetizing conglomeration to make fuel for power plants.

Borrowing technology from the steel industry, the company turns scrap metal into a 2,800-degree metal bath and injects construction debris deep into the bubbling cauldron. The process produces a clean-burning , or syngas, that can replace natural gas or fuel oil.

Ze-gen has been proving its technology and the quality of syngas over the past year, operating a demonstration plant here that digests about a ton of debris an hour. The company is now considering several sites, primarily in the Northeast, to develop a commercial facility that could eventually process as much as 30 tons an hour and produce enough gas to fuel a plant that could power 20,000 homes.

It expects to begin commercial production at the end of next year.

“We’re solving two problems,” said Bill Davis, Ze-gen’s chief executive. “We’re eliminating wastes that would end up in a landfill and reducing fossil fuels.”

Ze-gen is one of many companies across the nation using gasification technologies to convert plant, wood, and other organic wastes – known as biomass – into syngas. Some like, Ze-gen, are simply making syngas, which has the same chemical components, carbon and hydrogen, as fossil fuels. Others, like the Massachusetts Institute of Technology spinoff InEnTec LLC, of Bend, Ore., are condensing it into liquid to make ethanol.

InEnTec uses municipal solid waste as feed stock and a technology known as plasma gasification, initially developed at MIT several years ago to destroy hazardous materials. The technology essentially creates an artificial bolt of lightning that vaporizes materials. InEnTec applied the method to solid waste, producing a syngas, then introducing a catalyst to change the gas into liquid, which can be blended with gasoline.

InEnTec and a partner, Fulcrum BioEnergy Inc. of California, recently said they plan to break ground on a $120 million plant near Reno, Nev., by the end of the year, and begin commercial production of ethanol in 2010. The plant will process 90,000 tons of waste annually to produce 10.5 million gallons of ethanol. Including tipping fees (the charge for taking the waste), the company projects making ethanol for about $1 a gallon, said Dan Cohn, a cofounder of InEnTec and senior research scientist at MIT.

“Gasification has a lot of potential because the technology is well established and can process a very wide range of feed stocks,” Cohn said. “It has the greatest potential when you can process waste.”

Gasification, which uses heat to turn solids into gas, is indeed a well-established technology. Before the invention of the electric light, many cities and towns had plants that converted coal to gas for street lamps. With oil and natural gas prices soaring, coal gasification has gained new interest, but is controversial because coal gas produces high amounts of carbon dioxide, a greenhouse emission that contributes to global warming.

Using biomass as a feed stock is considered more environmentally friendly because plants and trees can be regrown to absorb carbon dioxide created by burning syngas. In addition, keeping waste out of landfills reduces an even more potent greenhouse gas, methane, which is released during decomposition.

Reducing solid waste was a key consideration in the founding of Ze-gen. Davis said more than 300 million tons of waste end up in US landfills every year, about 15 percent of it wood waste from construction. Ze-gen’s idea: Tap the waste’s energy potential.

The company’s engineers determined that channel induction furnaces used in the steel industry provided an energy-efficient way to turn construction debris into a high-quality, clean syngas. The electricity used for the furnace offsets about 15 percent of the energy produced by the syngas, Davis said.

The construction debris is first ground up, then injected deep into the molten metal with ceramic cylinders, much like dipping forks into a fondue pot. The intense heat converts the debris to gas. Heavy metals, such as lead from paint, settle to the bottom of the bath while other contaminants are trapped in crust of silica, known as slag, that forms on top.

Ze-gen raised about $8 million from investors to build the demonstration plant at a New Bedford waste-transfer station. The next step is to find industrial partners to put the gas to work. Syngas is difficult and expensive to transport, so Ze-gen’s plan is to build production facilities near users such as power and cogeneration plants at large factories. Cogeneration produces steam as well as electricity.

Several large companies have expressed interest, Davis said. He estimates the company could make syngas for about 75 percent of the current price of natural gas on commodities markets, and less than half that of fuel oil. Tipping fees for taking the waste could further lower the cost, he said.

As Biomass Power Rises, a Wood-Fired Plant Is Planned in Texas

The city of Austin, Tex., approved plans on Thursday for a huge plant that will burn waste wood to make electricity, the latest sign of rising interest in a long-dormant form of renewable energy.

When completed in 2012, the East Texas plant will be able to generate 100 megawatts of electricity, enough to power 75,000 homes. That is small by the standards of coal-fired power plants, but plants fueled by wood chips, straw and the like — organic materials collectively known as biomass — have rarely achieved such scale.

Austin Energy, a city-owned utility, has struck a $2.3 billion, 20-year deal to be the sole purchaser of electricity from Nacogdoches Power, the company that will build the plant for an undisclosed sum. On Thursday, Austin’s City Council unanimously approved the deal, which would bring the Austin utility closer to its goal of getting 30 percent of its power from renewable sources by 2020.

“We saw this plant as very important because it gives us a diversity of fuels,” said Roger Duncan, general manager of Austin Energy. “Unlike solar and wind, we can run this plant night or day, summer or winter.”

More than 100 biomass power plants are connected to the electrical grid in the United States, according to Bill Carlson, former chairman of USA Biomass, an industry group. Most are in California or the Northeast, but some of the new ones are under development in the South, a region with a large wood pulp industry.

The last big wave of investment in the biomass industry came during the 1980s and early 1990s. Interest is rising again as states push to include more renewable power in their mix of electricity generation.

Last week, Georgia Power asked state regulators to approve the conversion of a coal plant into a 96-megawatt biomass plant. An additional 50-megawatt plant in East Texas is expected to be under construction by September.

Mike Whiting, chief executive of Decker Energy International, a developer and owner of four biomass plants around the country, estimates 15 to 20 new biomass plants are proposed in the Southeast, though not all will be built. The region is, he said, “the best part of the U.S. for growing trees.”

In California, which has the most biomass plants in the country, momentum is reviving after years of decline. The number of biomass plants has dropped to fewer than 30, from 48 in the early 1990s, because of the closing of many sawmills and the energy crisis early this decade, said Phil Reese of the California Biomass Energy Alliance. Six to eight of the mothballed plants are gearing up to restart, Mr. Reese said, helping California meet its renewable energy goals.

At least three biomass plants have been proposed in Connecticut, and another three in Massachusetts — though last week one of these, a $200 million, 50-megawatt biomass plant proposed for the western part of the state, experienced a regulatory setback because of concerns about truck traffic.

Some environmental groups have opposed the Nacogdoches plant. Cyrus Reed, conservation director of the Sierra Club’s Lone Star chapter, said the plant was not “as clean as it could be” in terms of emissions. He also criticized the lack of a competitive bidding process to build the plant.

Pulp and paper companies operating in wooded East Texas have also opposed the plant, which will require a giant amount of wood residue — one million tons each year. They are concerned that there is not enough wood for their industry and the plant. But Tony Callendrello, vice president of Nacogdoches Power, said the company would use only discarded forest residues, mill waste and the like.

“We have no need — and no intention — to go after anything that the forest-products companies would be using in their production,” he said.