BLACKSBURG, Va. — Breakthroughs in bioplastics could help break down two of the world’s most pressing problems at once, says a Virginia Tech professor researching to improve production of food-based, cost-effective, decomposable plastic.
At Virginia Tech, Zhiwu ‘Drew’ Wang is director of the Center for Applied Water Research and Innovation, and assistant professor for the Department of Biological Systems Engineering.
“People already know a lot about the food waste problem, and they should also know a lot about the plastic problem,” he said. But, “Usually, people don’t see the correlation between food waste and plastic waste.”
In a specially designed lab, Wang is readying to upscale production of PHA-based bioplastic, repurposing waste food scraps. It’s funded by a $2.4 million grant from the U.S. Department of Agriculture, and is a continuation of earlier grant-paid bioplastic research, he said.
“I can convert food waste to plastic,” Wang said. “These two individual, separate problems can be addressed in this one technology, all together.”
Having already completed lab-scale studies of bioplastic production at Virginia Tech for the U.S. Department of Energy, Wang is now tasked by the USDA to upscale the process and bring it closer to real-world uses.
“There is a trend in the U.S. that universities should not only publish papers,” Wang said. “They should also develop technology that can be useful. Useful, that’s the key word.”
Uses for bioplastic are as wide-ranging as for regular plastic, but with the added benefit of lowering fossil fuel usage, and reducing trash that ends up in landfills or as litter, he said.
“Our current plastic, part of that goes to the landfill, the rest goes to the ocean,” Wang said. “Plastic is non-biodegradable, so it will stay in the landfill or in the ocean for hundreds of years.”
But bioplastic is biodegradable, which means bacteria and other natural organisms can break it down into simpler, further-decaying components. In fact, bacteria is key to making PHA bioplastic, Wang said.
“It’s as simple as that: grow the fat in the bacteria by using the food waste as the bacteria’s food, and then kill the bacteria to recover their fat,” he said. “Then process those fats into whatever bioplastic product I will want. For example, packaging film, that’s a flexible plastic.”
He said all food waste — whether it comes from a restaurant, home kitchen, processing company or even a slaughterhouse — contains three main components: fat, carbohydrates and protein.
“Whatever food waste comes in, we separate them into those three factions,” Yang said. “And now we use three types of microbial communities to take care of them individually.”
At an on-campus lab created just for this project, Wang and student researchers will sort food waste by the truckload.
“Usually a university doesn’t have a lab for pilot-scale studies,” Wang said. “Pilot-scale means it’s almost full-scale production. It’s like a factory, rather than like a lab.”
The product extracted from those fat, carb and protein-munching bacteria are PHAs, or Polyhydroxyalkanoates. It’s a type of biopolymer, he said.
“Most bioplastics are biodegradable in a landfill,” Wang said. “But PHA is the only bioplastic that is biodegradable in the ocean, so that’s one advantage of this type of bioplastic.”
For Wang, it’s not a question of whether the bioplastic production process works, but to what extent can he successfully scale up the operation? And how cost-effective is the technology at scale?
“If I say I want to replace the fossil fuel-powered plastic, it might be too ambitious,” Wang said. “By now at least I can say… We have the confidence that our technology can out-compete other bioplastic technology.”
Electric cars, solar panels and bioplastics face similar challenges, he said. Newer, more environmentally sustainable technologies tend to be more expensive than traditionally established products that use fossil fuels.
“It’s still hard for bioplastic to compete with the fossil plastic in terms of cost,” Wang said. “But many big companies, they want to have a much better public image, so they hope they can pay a little bit more money to use the bioplastic.”
Bioplastic research at Virginia Tech is one of three projects selected by the USDA to help develop new bioproducts from agricultural commodities, said Jewel Bronaugh, USDA deputy secretary of agriculture.
“It’s going to help us do this on a bigger platform,” Bronaugh said. “These particular projects all have an environmental justice component that we feel is really important.”
For bioplastic’s connection to environmental justice, she said waste management facilities are usually located in underserved communities.
“It’s certainly exciting for this opportunity to be going to Virginia Tech,” Bronaugh said. “The research they’re trying to do with their project is going to create potential opportunities in rural communities and underserved communities.”
Bioplastic fits into the idea of a circular economy, Bronaugh said. A circular economy emphasizes extending the lifespan of materials for as long as possible, different from current linear economies throwing so much away into landfills.
“By that, we mean that we don’t just pull resources out of rural communities,” Bronaugh said. “We’re not just harvesting and consuming, but we’re regenerating in a sustainable manner the opportunities for new product development, new research and new economic development in rural communities.”
Meanwhile at the University of Illinois Urbana-Champaign, a different pilot project is upscaling a process to convert swine manure into binding material for asphalt. It’s another example of changing the narrative on what constitutes waste, said Wang at Virginia Tech.
“The new direction for cleaning waste is to turn the waste into something valuable, that’s the circular economy,” Wang said. “If everybody thinks waste is also a resource, then the world will become much better.”