As much as we may want to recycle, our trash bins fill with dirty paper towels, pizza boxes, fabric bits and apple cores, helping account for the 165 million tons of non-recycled garbage Americans produced last year.
A Triangle-based company has now come up with a way to turn that trash into treasure. Well, fuel.
The secret is using enzymes. Novozymes, a company with its North American headquarters in Franklinton, develops and supplies enzymes – biological molecules that speed up chemical reactions. Some of Novozymes products remove stains, some keep bread from going stale.
Now scientists at the North Carolina lab have developed enzyme technology that can convert trash into ethanol. They have partnered with Fiberight, a biofuels company in Baltimore, to demonstrate the concept at an industrial scale.
Fiberight has built a plant in Lawrenceville, Va., north of Lake Gaston, and expects to be in full production in the fall.
“It’s a cool and intriguing idea,” said Armindo Gaspar, the Novozymes scientist in charge of the collaboration. “The (municipal solid waste) industry hadn’t thought about using biotech.”
The United States used 134 billion gallons of gasoline in 2011. Fiberight claims that processing all of the garbage in the U.S. using enzyme technology would produce 10 billion gallons of biofuel per year.
When trash arrives at the Fiberight plant, the company will separate out the glass, metal and plastic, reselling and recycling what it can. The rest of the solid waste is paper, textiles and bits of plant material, which will be turned into a pulp. This “biopulp” is about half of the total waste received.
The biopulp is then digested, meaning the cellulose that makes up the fibers in the pulp is broken down. A cellulose molecule is a long chain, hundreds to thousands of links long. Each link is a glucose molecule, which if freed, can be converted into ethanol. The goal is to break the chain apart. This violent task requires a gang of enzymes.
Humans don’t produce enzymes capable of doing this. That’s why cellulose is considered roughage to us, a key component of dietary fiber. To break down cellulose, enzymes must be stolen from other organisms, such as wood-eating fungi. Novozymes has developed a special cocktail of enzymes that do the job efficiently.
Once the glucose is free, it can be fermented into ethanol. At this stage, it’s no different from turning grapes into wine: add some yeast, and the sugar turns into alcohol.
The Virginia location is only a test site, with a peak production rate of 1 million gallons per year. But the testing is expected to go well. Fiberight already has a commercial plant under construction in Iowa, and expects to add many more in the next decade.
“The days of waste ending in a landfill are gone,” Craig Stuart-Paul, CEO of Fiberight, said in a statement. “We’re giving trash a new beginning.”