A sweeter way to make green products

September 08, 2017

The shampoo you washed your hair with this morning. The balloons for the party. Refrigerators and sunglasses, medicine and mosquito repellent, guitar strings and fishing lures. These -- and thousands of other products we use every day -- contain chemicals made from petroleum. But researchers at the University of Delaware can now offer manufacturers a much sweeter alternative to this fossil fuel.

A UD research team has invented a more efficient process for extracting the sugars from wood chips, corn cobs and other organic waste from forests and farms. This biorenewable feedstock could serve as a cheaper, sustainable substitute for the petroleum used in manufacturing tons upon tons of consumer goods annually -- goods that consumers want to be greener. More than half of consumers in the U.S. are willing to pay more for environmentally friendly products, according to GfK MRI's Survey of the American Consumer, reported earlier this year.

Basudeb Saha, associate director for research at UD's Catalysis Center for Energy Innovation -- a U.S. Energy Department-designated Energy Frontier Research Center -- led the effort, which involved scientists from UD and from Rutgers University. The results are published in ChemSusChem, a top interdisciplinary journal focusing on sustainable chemistry.

"To make greener chemicals and fuel, we're working with plant material, but we don't want to compete with its food value," Saha said. "So instead of taking corn and extracting its sugars to make ethanol, we're making use of the stalks and cobs left over after the corn is harvested, as well as other kinds of waste like wood chips and rice hulls."

Although the past decade has seen a shift toward using such waste, referred to as lignocellulosic biomass, to create chemicals for producing biodegradable plastics, pharmaceuticals, cosmetics and biofuels, biorefineries have struggled with finding steady supplies and with high processing costs.

Although wood chips and corn cobs may sound like simple, inexpensive materials, they are hard to break down chemically.

"The lignin that makes their cell walls so tough and sturdy acts like superglue, holding tightly to the sugars," Saha said.

UD invents one-step technology

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, though renewable, less competitive than those produced with petroleum.

The process invented at UD, however, is just one step. It doesn't require a separate pretreatment step commonly used in biorefineries 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 (one hour), which makes the method energy efficient. It's water efficient, too.

The key to the technology, which has been filed as an international patent application by UD, is the use of a concentrated solution of an inorganic salt in the presence of a small amount of mineral acid. 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, much like a newspaper swells when water spills on it.

The unique properties of the salt solution make the method very efficient, Saha said, with up to a 95 percent theoretical yield of sugars.

What's more, 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 be recycled. Furans are highly versatile compounds used as starting materials for making specialty chemicals.

The UD innovation employs process intensification, the performing of several steps in an integrated fashion, resulting in the use of less energy and water. This concept, implemented on a large scale, is the focus of RAPID, a Manufacturing USA Institute being led by the American Institute of Chemical Engineers, which also involves UD as a key player.

"Our process enables -- for the first time -- 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 than 10,000 million metric tons of carbon emissions were reported in 2010 from conventional fossil fuels and chemicals, which has a long-term catastrophic effect on our environment."
-end-
The study's co-authors included postdoctoral researcher Sunitha Sadula and research associate Weiqing Zheng from UD, and Prof. Marianthi Ierapetritou, chair of the Department of Chemical and Biochemical Engineering, and graduate student Abhay Athaley from Rutgers. The full article is available at this website.

About CCEI

The Catalysis Center for Energy Innovation (CCEI) is a partnership between the University of Delaware and Brookhaven National Laboratory, California Institute of Technology, Columbia University, Georgia Institute of Technology, Lehigh University, Rutgers University, University of Massachusetts, University of Minnesota and University of Pennsylvania. The center's mission is to develop chemical catalysts and associated technologies that can transform biomass such as trees, grasses and corn stover into fuel and chemicals. The center is funded by the U.S. Department of Energy.

University of Delaware

Related Corn Articles from Brightsurf:

Making sense of a universe of corn genetics
A new study details the latest efforts to predict traits in corn based on genomics and data analytics.

Redefining drought in the US corn belt
As the climate trends warmer and drier, global food security increasingly hinges on crops' ability to withstand drought.

Speedy recovery: New corn performs better in cold
Around the world, each person eats an average of 70 pounds of corn each year, with even more grown for animal feed and biofuel.

US corn yields get boost from a global warming 'hole'
The global average temperature has increased 1.4 degrees Fahrenheit over the last 100 years.

Genetic discovery may improve corn quality, yields
Researchers may be able to improve corn yields and nutritional value after discovering genetic regulators that synthesize starch and protein in the widely eaten grain, according to a Rutgers-led study.

Pollen genes mutate naturally in only some strains of corn
Pollen genes mutate naturally in only some strains of corn, according to Rutgers-led research that helps explain the genetic instability in certain strains and may lead to better breeding of corn and other crops.

Fungal mating: Next weapon against corn aflatoxin?
Native fungi combinations show promise against aflatoxin.

Scientists discover new 'architecture' in corn
New research on the US's most economically important agricultural plant -- corn -- has revealed a different internal structure of the plant than previously thought, which can help optimize how corn is converted into ethanol.

Breeding corn for water-use efficiency may have just gotten easier
With approximately 80 percent of our nation's water supply going towards agriculture, it's fair to say it takes a lot of water to grow crops.

Changing temperatures are helping corn production in US -- for now
Increased production of corn in the US has largely been credited to advances in farming technology but new research shows that changing temperatures play a significant role in crop yield.

Read More: Corn News and Corn Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.