Bio-based materials have been in the limelight lately because of their potential as low-emissions fuels, but their ability to cut CO2 emissions extends beyond the transportation sector, experts say.

Although ethanol and other biofuels receive the most media coverage for their ability to reduce gasoline consumption, companies around the world have been using them for some time as raw materials for a variety of other products, including textiles, plastics and cleaning solutions.

"The vision, the dream, is much bigger than fuel," said Steen Riisgaard, CEO of Novozymes, a biotech company.

By replacing the fossil fuels traditionally used to make a number of these products with more environmentally friendly bio-based materials, companies can reduce their carbon footprint, Riisgaard told United Press International.

And with governments around the world both considering and enacting tough climate-change legislation, including carbon tax proposals in the U.S. Congress, a number of companies may soon face mandates to decrease their emissions. At least, that's what companies like Novozymes project.

"For our business, we have no doubt it will be a big opportunity," Riisgaard said.

That's because Novozymes produces enzymes, proteins occurring in living organisms that act as catalysts for chemical reactions. Enzymes play a critical role in the conversion of biomass, like corn, into ethanol and are an important ingredient in making a number of other bio-based products. And their use can greatly decrease emissions, Riisgaard said.

"For every kilo of enzymes we sell, we save the planet 100 to 200 kilos of CO2," he said.

Last year the company produced 200,000 tons of enzymes, leading to 20 million tons in CO2 emissions reductions, according to company data.

As enzymes become more advanced, a number of companies are looking at new materials to make from biomass. Among these products is polyethylene, a plastic used heavily in commodities, such as disposable diapers and plastic toys. About 60 million tons of the material is produced every year from petroleum-based products, but Dow Chemical recently announced its plans to set up a plant in Brazil that will use sugar cane to produce the polymer.

At the facility, sugar cane will be converted to ethanol, which will then be used to produce polyethylene. This process is more environmentally sound than traditional polyethylene production, said Mauro Gregorio, business director of alternative feedstocks at Dow Chemical.

"There's a real potential to cut emissions because we're replacing the fossil fuel resources that are traditionally used to make (this) product," Gregorio told UPI.

The company estimates it will avoid using 1.8 billion tons of CO2 by substituting sugar cane for fossil fuel products at the plant. In addition, the sugar cane crops grown for the facility will remove another 1.5 billion tons of CO2 from the atmosphere through photosynthesis, Gregorio said.

The plant will start operating, at a capacity of 385,000 tons by 2011, according to a company release.

Enzymes also have advantages when used in detergents. By lowering wash times and decreasing temperature requirements, they save energy, a number of enzyme-producing companies say.

Whether companies are forced to lower emissions through government mandates, the enzyme business is looking good, said Hugh Welsh, vice president of DSM, a biotechnology company.

"The retail market has shown a lot of interest in this," Welsh told UPI. "Companies like Wal-Mart all want to move away from fossil fuel materials toward bio-based products."

This may reflect the preferences of consumers, who have increasing information about the sustainability of particular products. For instance, the Carbon Trust, a London-based government-established company, labels consumer products with information about their carbon footprint.

This allows businesses to "demonstrate their commitment to reducing the carbon emissions embodied in their products," thus attracting more consumers, according to Carbon Trust's Web site.

While bio-based products have the potential to decrease greenhouse gas emissions, many either use food-based fuel, such as the sugar cane ethanol used for the polyethylene plant in Brazil, or other food crops for raw material.

Although this doesn't reach the scale required for the transportation sector, recent concerns over traditional ethanol's intensive land and water requirements, as well as its effect on food prices, have prompted many biotechnology companies to look for new alternatives. As a result, many are now working to develop ethanol from cellulosic sources, or non-food crops.

Enzymes play a key role in the conversion of any biomass into ethanol, but cellulosic sources, such as switchgrass or wood, are much tougher to break down into sugars, a necessary step before they can be converted to fuel. To make cellulosic ethanol commercially viable, companies are working to create more efficient enzymes to be used in the process. Among them is Genencor, a biotechnology company.

"Without enzymes, it will be impossible to make cellulosic ethanol," said Genencor CEO Tjerk de Ruiter.

The company recently released Accellerase 1000, the first commercially available biomass enzyme developed specifically to convert cellulosic feedstocks into ethanol. So far, the response has been good, de Ruiter told UPI.

"I think we hit a sweet spot in the market," he said. "The response of people interested in using Accellerase in their systems has been beyond our expectations."

Other companies are also working to get enzymes on the market, but all of them need to significantly decrease costs, probably by as much as five to 10 times, said Thomas Nagy of Novozymes.

"The key to all this is to find a cost-efficient way to break down cellulose into fermentable sugars," Nagy told UPI. "Once you've solved that trick, the road is open to many applications."