Researchers Turned Bamboo and Sugar Waste into Biodegradable Tableware

FnB industry uses a lot of these, but single-use tableware like cups, plates, and containers contribute a lot to waste, even the ones with compostable labels. 

Compostable, single-use cutlery can still end up in a landfill because they won’t break down without the right conditions in composting facilities. Additionally, eco-friendly tableware stuff is often more expensive than conventional plastic. 

Businesses in the food and beverage field would find the upfront cost expensive. Mostly because consumers may not want to pay extra, so their initial spending/investment may not return. 

Scientists have found a solution: tableware that breaks down naturally in 60 days with a more affordable price than compostable plastic. How so? Because the materials are sugercane waste and bamboo. 

Astonishment turned to alternative 

Hongli Zhu, the co-author and assistant professor at Northeastern University came up with the idea. When Zhu first came to the U.S. in 2007, she says she was surprised at the amount of single-use containers in stores, at restaurants, and in the trash cans at her seminars. 

She said, “If you [look] at the whole population, I can’t imagine how much plastic waste this kind of onetime use food container waste we generate on Earth. People try to use materials created by humans, but I think we should look to nature. Nature has so much to offer.” 

Zhu and her team decided to start with sugarcane bagasse, the pulp byproduct of sugarcane extraction.  

In 2021, Brazil alone is expected to produce 39.5 million tons of sugar from its sugarcane harvest, and for every 10 tons of sugarcane crushed during extraction, there’s about three tons of pulp produced. 

Therefore, making this tableware is cheap and eco-friendly, because it’s already waste. “The problem is sugar fiber is short, so from a mechanical stance, waste from sugar cane is not so strong. We made a hybrid, mixing the shorter fibers with long bamboo fiber . . . [to] enhance the mechanical strength,” said Zhu. 

Formulating the perfect recipe 

When trying to come up with an alternative used for food and drink, there are some considerations. The greener versions have to be strong enough to hold liquids as plastic does.   

“Making food containers is challenging. It needs more than being biodegradable. On one side, we need a material that is safe for food; on the other side, the container needs to have good wet mechanical strength and be very clean because the container will be used to take hot coffee, hot lunch,” Zhu added. 

 Making bowls, cups, and containers from just bamboo is going to be more expensive. That would also still require all the water use and emissions associated with growing and harvesting more bamboo. 

Which is why Zhu avoided wood pulp, which is a common material for compostable packaging. She said, “That’s biodegradable for sure, but the cost is much higher than using waste from the sugar industry, and from an environmental point of view, if we use wood, we need to plant trees to do it.” 

Her team also stayed away from recycled paper fibers, because they may contain residual inks or chemicals. 

Bamboo x sugarcane 

Plastic needs industrial composting and temperatures over 140 degrees Fahrenheit. On the contrary, bamboo and sugarcane items can be buried right in the ground. When Zhu and her team buried this tableware in soil, it began to deform after 30 days and completely lost its shape and gradually disappeared at 60 days. 

“The chemical component in the end is cellulose—it’s the same chemical compound of grass, of a tree in your yard,” Zhu remarked. 

The scientists added alkyl ketene dimer (AKD), a widely used eco-friendly chemical in the food industry. That addition aims to increase oil and water resistance of the molded tableware, ensuring the sturdiness of the product when wet. 

Northeastern researchers said that the result is clean, sustainable, strong packaging. What’s more, its manufacturing process emits 97% less CO2 emissions than polystyrene plastic production, and 67% less than paper products and PLA, a common biodegradable plastic. 

Their biodegradable tableware outperformed commercial biodegradable food containers. For example, other bagasse-based tableware and egg cartons, in mechanical strength, grease resistance, and non-toxicity. 

Also, the cost is cheaper than biodegradable plastic too, at $2,333 a ton compared to $4,750 a ton for PLA production, and close to polystyrene, which comes in at $2,177 a ton. They’re currently working on to make the manufacturing process even more energy efficient and bring the cost down even more. 

“When we think of plastic alternatives, we should think about cost. In the end we want it so a customer can buy it . . . the cost needs to be competitive with plastic.  

“It is difficult to forbid people to use one-time use containers because it’s cheap and convenient. But I believe one of the good solutions is to use more sustainable materials, to use biodegradable materials to make these one-time use containers,” Zhu said. 

Online food deliveries with tableware reuse 

It’s even more common for us to order food online. Nothing beats the convenience. However, those billions of delivery meals produce an enormous amount of plastic waste from packaging, food containers, and cutlery. 

In one year, there could be about 7.3 billion sets of single-use tableware in China only. Around one-third of the 553 kilotons of municipal solid waste that is generated each day comes from packaging. 

A group of scientists from this country has analyzed if using paper alternatives or reusable tableware could reduce plastic waste and associated life cycle emissions. 

“We quantified the environmental impact and modelled different alternatives,” said Yuli Shan, one of the first authors of this paper. The alternatives to the single-use plastic tableware were single-use paper alternatives and reusable silicone tableware that is cleaned either by the restaurants that cook the food or in a central cleaning facility. 

Plastic vs paper vs silicone 

On a first glance, paper sounds like a good alternative. It’s from a natural material and it can degrade. But, single-use polyethylene-coated paper containers and bags actually increased emissions and total waste volume. 

“For those areas without paper waste collection and recycling systems, paper substitution is not the optimal option for addressing the takeaway packaging waste dilemma,” said Ya Zhou, associate professor at Guangdong University of Technology, and one of the first authors. 

Reusable silicon tableware could reduce plastic waste by up to 92%, and environmental emissions and water consumption by more than two-thirds. 

The researchers suggest getting an environmentally friendly and, at the same time, safe system of reusable tableware up and running requires some investments. 

“A central cleaning facility would be best, also for health inspections to ensure safety, but this requires a system for collecting the used sets,” said the researchers. 

Needing government’s help 

Suggestions from the researchers can help to achieve much less waste from online food business. But they also said that it needs government intervention to realize this. 

The Chinese government is taking steps to drastically reduce waste. A number of initiatives have sought new solutions for municipal solid waste management and plastic reduction. That includes a sorting implementation plan, a ‘zero-waste city’ pilot program and a nationwide single-use plastic ban as from January 2020. 

According to Shan, delivering food without tableware at all may be possible in some cases but not all takeaway orders. “Most meals are not eaten at home but in the classroom, during lunch breaks or at the office, when employees work late,” said Shan. 

Zhou added, “Reusing tableware provides a potential solution to reduce waste and emissions from takeaway meals and a new strategy for promoting sustainable and ‘zero-waste’ lifestyles.” 

 

Sources

https://www.fastcompany.com/90574439/this-bamboo-and-sugar-waste-tableware-biodegrades-in-60-days

https://www.sciencedaily.com/releases/2020/11/201112113139.htm

https://www.sciencedaily.com/releases/2020/09/200925113334.htm

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