As data continues to emerge on the damage being caused by discarded plastic persisting in the environment, it’s clear the millions of tons of the ubiquitous material we’ve already produced isn’t going away anytime soon.
Luckily, a host of scientists and researchers hard at work developing bio-based alternatives to plastic are making surprising discoveries — not only are they revolutionizing the material itself, they’re creating a whole new set of unexpected symbiotic relationships, wherein one industry’s manufacturing waste becomes feedstock for another.
Here are some of our favorite waste-to-plastic innovations from this year:
Juice wastewater
An EU-funded program announced in February is developing a method for making plastic packaging from the fermented wastewater of processed juice, which could save the beverage industry millions. Through the PHBOTTLE project, researchers believe that since juice-processing wastewater contains up to 70 percent concentrations of organic substances, including fermentable sugars such as glucose, fructose and maltose, it could be an ideal and cheap source of raw material to produce an organic compound called PHB, a type of biopolymer. The European Commission says PHB is moisture- and vapour-resistant, won’t dissolve on contact with water, has see-through properties and offers good protection against oxygen, all of which help to slow food spoilage — making it perfect for making biodegradable juice packaging.
Shrimp shells
Researchers at Harvard's Wyss Institute announced in May they have developed a new process for the large-scale manufacturing of everyday objects — from cell phones to food containers and toys — using a fully degradable bioplastic made from chitosan, a form of chitin, a powerful natural polymer and the second most abundant organic material on the planet, which makes up shrimp shells. The Institute said the objects display many of the same properties as those created with synthetic plastics, but are more eco-friendly — even more so than many of today's bioplastics in that they create no threat to trees or competition with the food supply. The researchers say the chitosan bioplastic also breaks down when returned to the environment within about two weeks, and releases nutrients that support plant growth.
Tomato skins
When researchers at Heinz were looking for uses for the peels, stems and seeds from the over two million tons of tomatoes the company uses annually to produce its signature ketchup, they naturally (?) turned to Ford. The two companies announced in June they are investigating the use of dried tomato skins— a waste product of the ketchup-making process — as bio-based composite materials for use in vehicle parts, such as wiring brackets or a storage bin used to hold coins and other small objects in a Ford vehicle.
Agricultural waste
Researchers at the Italian Institute of Technology announced in July they are experimenting with producing plastics from biomass so that the materials are renewable, biodegradable, and possibly less toxic. The team used a technique that’s normally used to break cellulose down into simpler sugars for biofuel production — soaking the material in acid. The team used trifluoroacetic acid (TFA) to soak inedible waste from four food crops: spinach, rice, cocoa beans and parsley — the result was plastic coatings and films with a variety of mechanical properties and tensile strengths similar to synthetic polymers such as polyethylene terephthalate and polyethylene. Like synthetic polymers, these plant-waste plastics also thermally degrade at temperatures between 150-300 ºC.
Pulp and paper waste
Results of a research project released in June by Biome Bioplastics, one of the UK’s leading developers of natural plastics, demonstrated the feasibility of extracting organic chemicals from lignin— a complex hydrocarbon that helps to provide structural support in plants and trees — for the manufacture of bioplastics. As a waste product of the pulp and paper industry, lignin is an abundant and low-cost feedstock for high-performance chemicals that Biome says could provide the foundation for the next generation of bioplastics.
And UK waste-management company Network Waste announced in September it has been working with the Adapt Low Carbon Group at the University of East Anglia on a project that could lead to paper waste being turned into bioplastic. The two are partnering on a project involving paper crumb— the waste from paper milling — in cooperation with a Network Waste customer that produces up to 7,000 tons of damp paper crumb per year at its mill. The waste is currently spread on land through an energy-intensive process that requires removal of large amounts of water — the company asked Adapt to investigate whether a more sustainable commercial use could be found for the material. The teams are exploring the conversion of paper crumb into intermediates that can be used in the bioplastic manufacturing process; the crumb could also be used in the construction industry to be blended with concrete.
These are just a few of the promising innovations we heard about this year. Please let us know about any we may have missed!