By Austen Verrilli, CG Science
A piece of pie, the plate it rests on, the knife that dissects it and the fork that scoops it into the mouth all have one thing in common: sugar.
Sugarcane is the basis for compostable plates, bowls, cutlery and even clear disposable food containers. The products exist as alternatives to traditional disposable eating products. Ohio University’s Baker Center adopted the sugary alternatives in accordance with the university’s sustainability goals.
Sugar manufacturers crush the juice out of sugar cane stalks to make table sugar. Large scale sugar production results in huge amounts of waste sugar cane stalks, called bagasse. The companies burn the stalks to make energy for the plant or throw them away.
Stalkmarket Compostable Products, one of OU’s suppliers of biodegradable products, saw the availability of sugarcane stalk “waste” and decided to use it. Buzz Chandler, of Stalkmarket, says that even companies who burn the stalks for power have excess they have to throw away.
Stalkmarket takes these stalks and grinds them up into a pulp. The pulp is then made into a pulp board, similar to the paper making process. The pulp board is ground up once more and the material is formed into plates and bowls. Stalkmarket also makes clear food containers and cutlery that resembles plastic. The difference? Stalkmarket ferments and distills polylactic acid from sugar refining wastes. Polylactic acid forms a resin that becomes food containers, cups and cutlery.
Sugarcane-based compostable products eliminate the need for recycling because the materials biodegrade themselves. Recycling has many steps, takes large amounts of energy and has a low success rate. Six percent of plastics used get recycled, Chandler said.
“Recyclable material exists but the infrastructure to recycle is almost nonexistent,” Chandler said.
Furthermore, any food on plastics or papers contaminates the chemical make-up of recycled material. Fats, oils and other food wastes dilute and ruin chemical bonds in batches of recycled material. Recycling facilities typically throw plastic and paper materials with food on them away rather than cleaning them because most facilities lack cleaning machines.
Ohio University is a test mule for the sugar cane products, said Erin Sykes of the OU Office of Sustainability. So far the products work and break down in the composter. But, the sugar cane products decompose slower than the university anticipated.
Sugar cane bagasse products take 30 to 40 days to break down. Bioresins take 60 to 90 days to compost. Chandler said that the bagasse products break down easily but the bioresins require a maintained temperature and commercial grade composters to decompose in a timely manner.
Another issue with the compostable products is user sorting. Improper sorting nullifies the sustainability benefit of the sugarcane products.
Compostable plates, bowls, containers and cutlery require certain conditions to break down which landfills sometimes lack. Chandler described successful composting as, “a combination of heat, moisture, oxygen and microbial action.”
Sykes says the university has done well sorting compostable products so far. “But there will always be some contaminates,” she said.
The American Recovery and Reininvestment Act recently awarded the Office of Sustainability $1,088,571 to expand the university’s composting facility. The Office of Sustainability plans to address slow composting of sugarcane materials with some of these funds, Sykes said. A shredder may be added to the composting facility to make the material break down faster by decreasing surface area of waste particles.
The Office of Sustainability also plans to add an additional four-ton composter, solar array and solar thermal water heater to the university’s existing two-ton composting facility. The new setup should enable 100 percent of food wastes from university facilities and dining halls to be composted. Currently, the university only composts biodegradable waste from Shively Dining Hall and Baker Center.