Plastics are a major problem and becoming so pervasive that they’re even being found in bottled water, according to recent news reports. The majority of plastics are non-biodegradable, but Zhiwu (Drew) Wang, PhD, assistant professor and extension specialist with the Department of Biological Systems Engineering, Virginia Tech, has found a way to make biodegradable bioplastics from food waste.
“Bioplastics are made from fat-like polymer produced by bacteria that eat the food waste,” Wang says. “We then kill the bacteria, which opens their cell walls, allowing us to recover the polymer and process it into bioplastic.”
The entire process can be accomplished in five to seven days, but the process is typically costly, compared to producing plastic from petroleum. The bioplastics produced by Wang and his team can easily compete with other bioplastics on the market, for one simple reason—the source of their basic input materials.
“We’ve reduced the cost by utilizing food waste, which doesn’t cost anything,” Wang adds. “Bioplastics also reduce greenhouse gases (GHGs), so we can earn carbon credits from them.”
Because food waste is carbon neutral, it doesn’t contribute to GHG emissions by creating a closed carbon loop. Using food waste to create bioplastics is a great example of circularity.
But not just any kind of food waste will work. The term “food waste” is quite broad, as there are different food waste sources and types. Wang’s team has eliminated that problem by using biofunneling—a process where variable types of food waste are put in, with the product coming out being more uniform. That uniform element is then fed to the bacteria.
Many states currently do not allow food waste to be put into landfills, a trend Wang predicts will continue. In the meantime, his team’s alternative solution to food waste disposal will continue being evaluated.
“Our next step is to conduct an economic analysis on this process lifecycle,” Wang says. “Typically, bioplastics that are produced are too tiny to characterize the quality and estimate the costs of the process, but we have been able to produce enough bioplastics to conduct an entire economic analysis. This process solves two problems: the issue of plastics and food waste.”