Tiny Firm Sees Process as Big Answer to Waste

Scientists have long dreamed of converting the mountains of waste we produce in our cities and factories and on our farms into something useful. Now they may be on the edge of success.

A tiny Massachusetts company, working with the Energy Department, the state of New York and several other firms, has developed the technology to convert cellulose into an acid that can be used to produce a wide range of products, from alternative fuels to fertilizer. Cellulose is the sugar that makes up the cell walls of plants, and it is the raw material for many manufactured goods, such as paper. It is also the most common waste product of many manufacturing processes.

Our landfills are literally overflowing with the stuff.

For 150 years, scientists have known that if cellulose is mixed with acid and heated, it produces levulinic acid, known as a “platform chemical” because it can be used for so many different purposes. But the yield from cellulose conversion processors has been low--only about 25% levulinic acid to 75% tar. That has driven the cost of the acid up to $5 to $10 per pound, thus thwarting its potential.

So for the last 10 years, Stephen Fitzpatrick, a chemical engineer who heads a three-person company, Biofine Inc., of Waltham, Mass., has been developing the technology to produce levulinic acid much more cheaply. A demonstration plant, funded by a $3-million grant from the Energy Department and $1 million from the state of New York, has converted cellulose to levulinic acid at much higher yields. The demonstration plant produces the acid at a cost of 4 cents to 32 cents per pound, according to the New York State Energy Research and Development Authority.

“It’s an exciting technology,” said Jeff Peterson, program manager for the state agency.

The demonstration plant at South Glens Falls, N.Y., converts waste sludge from a paper-processing plant into levulinic acid at the rate of about a ton per day. That’s enough to prove the viability of the technology, but much larger plants capable of converting up to 1,000 tons of cellulose a day are needed for the promising acid to support the many applications that could grow out of cheaper availability.

According to New York studies, that could drive the demand for levulinic acid up from its current worldwide level of 1 million pounds per year to as much as 1 trillion pounds.

At the same time, it would convert one of the most common waste products in the world into a wide range of useful products.

The beauty of the process lies in its simplicity. There is already an abundance of concentrated waste deposits around the world to provide the “feed stock” for a conversion plant.

“We could plunk it down next to a paper mill, or near a number of paper mills, and take that stuff away,” Fitzpatrick said. The “stuff,” consisting mostly of cellulose fibers, would otherwise go to a landfill where it would decay and release carbon dioxide, a “greenhouse” gas blamed for global warming.

Fitzpatrick’s process, for which he holds two patents, reduces the time the cellulose remains in a processing vessel, called a reactor, and causes levulinic acid to form “preferentially” to tar. Only 25% emerges as tar, Fitzpatrick said, and it comes out almost like coal.

The coal-like substance, he said, is a perfect fuel to run the plant. “We can burn that and make steam and electricity for the process,” he said. “We’re almost a net zero user of power to do all this.”

Douglas C. Elliott, a chemist at the Energy Department’s Pacific Northwest National Laboratory in Richland, Wash., believes the technology could lead to a new generation of alternative fuels, especially for fleet vehicles under federal mandate to use cleaner fuel.

Elliott and his co-workers have created what the lab calls “the first-ever multi-step catalytic process that converts levulinic acid into an alternative fuel component called methyltetrahydrofuran,” more commonly known as MTHF.

MTHF can be combined with natural-gas liquids to produce a clean-burning fuel for vehicles, thus converting what was once a waste product into a gasoline substitute.

“Biofine has been able to refine levulinic acid production to the point that they can get a high enough yield to make it interesting economically,” Elliott said. “And in the process, they remove all of the other contaminants that would hurt our catalyst and give us a clean product to work with. That makes it a lot easier on our end to come up with a final product of value.”

The reactor at the Northwest lab would have to be scaled up considerably to make the conversion of levulinic acid to MTHF economically rewarding, but Elliott said that’s no problem.

“A reactor like this is pretty easy to scale up,” he said. “We don’t have any fancy tricks wrapped up inside the reactor. We just need a bigger pipe.”

But making things bigger also means spending more money, possibly a lot of it.

“The biggest step is to go from a demonstration plant to a really big commercial plant,” Fitzpatrick said. “It’s not a technical risk, it’s a financial one. That’s the biggest downside, the fact that you are putting $50 million into a new technology.”

Fitzpatrick said two of the country’s largest chemical companies, which he declined to name, are studying the economic feasibility of the process, and he sees a potentially global market. “Lots of countries have no mineral resources, but they’ve got lots of vegetation and lots of cellulose,” he said. “One could imagine that this could be even more broadly used worldwide.”

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Lee Dye can be reached via e-mail at leedye@compuserve.com.