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Researchers To Convert Starbucks Coffee Grounds into Bio-Plastic
August 24, 2012
Starbucks is funding research in Hong Kong to convert coffee grounds and leftover bakery goods into bioplastics, laundry detergents and other everyday products.
Carol S. K. Lin of the City University of Hong Kong leads the biorefinery research team and presented the work this week at the National Meeting & Exposition of the American Chemical Society.
Just as oil refineries convert petroleum into fuels and ingredients for hundreds of consumer products, biorefineries convert corn, sugar cane and other plant-based material into a range of ingredients for bio-based fuels and other products.
Estimates suggest 1.3 billion tons of uneaten food are dumped in landfills and otherwise wasted around the world every year. In Hong Kong alone, Starbucks produces 5,000 tons of used grounds and waste bakery items every year.
“We are developing a new kind of biorefinery, a food biorefinery, and this concept could become very important in the future, as the world strives for greater sustainability,” Lin explained. “Using corn and other food crops for bio-based fuels and other products may not be sustainable in the long run. Concerns exist that this approach may increase food prices and contribute to food shortages in some areas of the world. Using waste food as the raw material in a biorefinery certainly would be an attractive alternative.”
The Starbucks project took shape during a meeting last summer between representatives of the nonprofit Climate Group and Lin at her laboratory in Hong Kong. The Climate Group asked if her biorefining technology could be applied to the wastes of one of its members — Starbucks Hong Kong. To help jump-start the research, Starbucks Hong Kong donated a portion of the proceeds from each purchase of its “Care for Our Planet Cookies” gift set.
The food biorefinery process involves blending baked goods with a mixture of fungi that excrete enzymes to break down carbohydrates in the food into simple sugars. The blend then goes into a fermenter, a vat where bacteria convert the sugars into succinic acid. Succinic acid topped a U.S. Department of Energy list of 12 key materials that could be produced from sugars and that could be used to make high-value products - everything from soaps to medicines.
In addition to providing a sustainable source of succinic acid, the new technology could have numerous environmental benefits. Currently, the majority of food waste is incinerated or disposed of in landfills. By avoiding incineration, fewer pollutants enter the atmosphere, and by avoiding landfills, less methane (a greenhouse gas) is produced, while retaining the inherent value of the bio material. Because succinic acid and its products are made using food waste as a renewable feedstock, they are sustainable alternatives to products made with nonrenewable petroleum.
Lin said that the process could become commercially viable on a much larger scale with additional funding from investors. “In the meantime, our next step is to use funding we have from the Innovation and Technology Commission from the Government of the Hong Kong Special Administrative Region to scale up the process,” she said. “Also, other funding has been applied to test this idea in a pilot-scale plant in Germany.”
Thirty-nine percent of Americans feel guilty about wasting food, according to a survey released earlier this month that asked about “un-green” activities such as not recycling, forgetting to bring reusable bags to the store, and leaving the lights on when leaving a room
@Bart_King is a freelance writer and communications consultant.