In the not-too-distant future, University of Nevada, Reno
researcher Manoranjan Misra can envision a day when customers
might pull into the drive-through at Starbucks for a cup of coffee
??? and then fill their cars with biodiesel made from the same
coffee grounds that produced their tasty latte.
Misra, a professor of chemical and metallurgical engineering, has
developed a novel process ??? believed to be the first of its kind
in the country ??? to extract high-quality biodiesel from spent
Misra???s process has important implications in the world???s
efforts to combat global warming through the creation of
alternative fuels such as biodiesel.
What sets his work apart from other biodiesel efforts is the high
quality of the biodiesel extracted from coffee grounds. The
process also utilizes an inexpensive waste product, thus reducing
???We have found that biodiesel created from spent coffee grounds
is stable over a longer period of time than other forms of
biodiesel that have been created from feed stocks such as soy and
corn,??? Misra said. ???Biodiesel from spent coffee grounds is a
low-cost ???green??? form of fuel that shows a significant
reduction of carbon dioxide emission. It???s an excellent source
Using Starbucks as an example, Misra said that the coffee-making
giant generates more than 200 million pounds of spent coffee
grounds per year in the United States.
???We estimate that this could produce almost 3 million gallons of
biodiesel per year,??? Misra said.
Misra???s process, which has been patented, involves two simple
steps: the extraction of oil from the spent coffee grounds, and
then the conversion of the oil to biodiesel.
He said that the produced oil is a triglyceride, which is the
chemical form in which most fat exists in food. The
triglycleride-rich oil easily lends itself to biodiesel
conversion, and serves as an agent to reduce carbon dioxide
emissions when it is burned as fuel.
Removal of one pound of triglyceride from coffee grounds would
reduce about three pounds of carbon dioxide, making it a highly
effective agent in battling the continued accumulation of
greenhouse gases, Misra said.
Worldwide, the potential for the new ???coffee??? biodiesel is
great, Misra said. He noted that about 15 billion pounds of coffee
is consumed in the world; of this, the new technology could
potentially produce more than 200 million gallons of biodiesel. In
northern Nevada alone, about 70 million pounds of coffee is
produced at the Starbucks roasting plant in the Carson Valley.
Misra said he created the technology almost by accident.
???I had left my coffee out one night, and the next morning, I
noticed that there was a kind of oil around the edge of the
cup,??? he said. ???Every cup of coffee has it. I decided to do
some tests on the oil.???
He discovered that the oil, rich in triglycerides, could be easily
converted to biodiesel.
???The oil still smells like coffee,??? he said. ???It doesn???t
change a lot during the process.???
~Crystal D. Hartman