Researchers in Nevada are reporting that waste coffee grounds
can provide a cheap, abundant, and environmentally friendly source of biodiesel
fuel for powering cars and trucks. Their study appears in the current online
issue of ACS’ Journal of Agricultural and
Food Chemistry, a bi-weekly publication.
In
the new study, Mano Misra, Susanta Mohapatra, and Narasimharao Kondamudi note
that the major barrier to wider use of biodiesel fuel is lack of a low-cost,
high quality source, or feedstock, for producing that new energy source. Spent
coffee grounds contain between 11 and 20 percent oil by weight. That’s about as
much as traditional biodiesel feedstocks such as rapeseed, palm, and soybean
oil.
Growers produce more than 16 billion
pounds of coffee around the world each year. The used or “spent” grounds
remaining from production of espresso, cappuccino, and plain old-fashioned cups
of java, often wind up in the trash or find use as soil conditioner. The
scientists estimated, however, that spent coffee grounds can potentially add 340
million gallons of biodiesel to the world’s fuel supply.
To verify it,
the scientists collected spent coffee grounds from a multinational coffeehouse
chain and separated the oil. They then used an inexpensive process to convert
100 percent of the oil into biodiesel.
The
resulting coffee-based fuel — which actually smells like java — had a major
advantage in being more stable than traditional biodiesel due to coffee’s high
antioxidant content, the researchers say. Solids left over from the conversion
can be converted to ethanol or used as compost, the report notes. The scientists
estimate that the process could make a profit of more than $8 million a year in
the U.S. alone. They plan to develop a
small pilot plant to produce and test the experimental fuel within the next six
to eight months.
— An American Chemical Society (ACS) News Release on December 17, 2008.