A biorefinery (right) turns used coffee grounds and uneaten bakery items like those shown on the left into detergents and bio-plastics. Credit: Carol Lin, Ph.D. |
With
1.3 billion tons of food trashed, dumped in landfills and otherwise
wasted around the world every year, scientists today described
development and successful laboratory testing of a new “biorefinery”
intended to change food waste into a key ingredient for making plastics,
laundry detergents and scores of other everyday products.
Their
report on a project launched in cooperation with the Starbucks
restaurant chain?concerned with sustainability and seeking a use for
spent coffee grounds and stale bakery goods?came at the 244th National
Meeting & Exposition of the American Chemical Society. Thousands of
scientists and others are here this week for the meeting of the world’s
largest scientific society, which features almost 8,600 reports on new
discoveries in science.
“Our
new process addresses the food waste problem by turning Starbucks’
trash into treasure—detergent ingredients and bio-plastics that can be
incorporated into other useful products,” said Carol S. K. Lin, Ph.D.,
who led the research team. “The strategy reduces the environmental
burden of food waste, produces a potential income from this waste and is
a sustainable solution.”
The
idea took shape during a meeting last summer between representatives of
the nonprofit organization called The Climate Group and Lin at her
laboratory at the City University of Hong Kong. The Climate Group asked
her about applying her transformative technology, called a biorefinery,
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.
Lin’s
team already had experience in developing the technology needed to do
it?a so-called biorefinery. 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.
“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.”
Lin
described the food biorefinery process, which involves blending the
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 laundry detergents to plastics
to medicines.
In
addition to providing a sustainable source of succinic acid, the new
technology could have numerous environmental benefits, Lin explained.
For example, Starbucks Hong Kong alone produces nearly 5,000 tons of
used grounds and unconsumed waste bakery items every year. Currently,
this waste is incinerated, composted or disposed of in landfills. Lin’s
process could convert these piles of foul-smelling waste into useful
products, getting trash off the land. By avoiding incineration, fewer
pollutants enter the atmosphere. In addition, the carbon dioxide that is
produced is reused during the biorefining process. Because succinic
acid and its products (such as bio-plastics) are made using bakery waste
as a renewable feedstock, they are sustainable alternatives to products
(such as regular plastics) that are now made with petroleum, a fossil
fuel that is nonrenewable.
The
method isn’t just for bakery waste—Lin has also successfully
transformed food wastes from her university’s cafeteria and other mixed
food wastes into useful substances with the technology.
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.”