extracting sugars from wood
Researchers invented a process for extracting the sugars from wood chips, corn cobs and other organic waste from forests and farms.
This bio-renewable feedstock could serve as a cheaper, sustainable substitute for the petroleum used in manufacturing consumer goods. More than half of consumers in the U.S. are willing to pay more for environmentally friendly products.
“To make greener chemicals and fuel, we’re working with plant material, but we don’t want to compete with its food value,” said, Basudeb Saha, associate director for research at UD’s Catalysis Center for Energy Innovation. Researchers taking corn and extracting its sugars to make ethanol. The stalks and cobs left over after the corn harvests, as well as other kinds of waste like wood chips and rice hulls. Wood chips and corn cobs are hard to break down chemically.
Researchers said, the lignin makes their cell walls so tough and sturdy acts like superglue, holding tightly to the sugars. Industry currently separates out the sugars from the lignin through a two-step process using harsh chemicals and reaction conditions in the first step, and an expensive enzyme in the second step. This process makes the resulting sugars expensive and the end products, less competitive than those produced with petroleum.
UD’s one-step technology
The process commonly used in bio-refineries to disintegrate the lignin from the sugar polymers cellulose and hemicellulose. UD’s one-step technology integrates the pretreatment step and the hydrolysis of cellulose and hemicellulose in one pot and operates at considerably low temperature (85°C) and short reaction time, which makes the method energy efficient. It’s water efficient, too.
The key to the technology is the use of a concentrated solution of an inorganic salt. The concentrated salt solution requires a minimal amount of water. The solution swells the particles of wood or other biomass, allowing the solution to interact with the fibers, like a newspaper swells when water spills on it.
The unique properties of the salt solution make the method very efficient with up to a 95 percent theoretical yield of sugars.
The team has integrated the process with another step, called the dehydration reaction. Which converts the sugars to furans in the same pot and enables the salt solution to recycle. Furans are highly versatile compounds used as starting materials for making specialty chemicals.
The performing of several steps in an integrated fashion, resulting in the use of less energy and water.
“Our process enables the economical production of feed streams that could profoundly improve the economics of cellulosic bioproducts manufactured downstream, not to mention the environmental benefits of replacing petroleum,” Saha says.
More information: [ChemSusChem]