Waste coffee grounds offer new source of biodiesel fuel

December 10, 2008
Waste coffee grounds can provide a cheap, abundant source of biodiesel fuel (shown), researchers say.Credit: Narasimharao Kondamudi, University of Nevada-Reno

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 has been published online in the American Chemical Society's (ACS) Journal of Agricultural and Food Chemistry.

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.

Biodiesel is a growing market. Estimates suggest that annual global production of biodiesel will hit the 3 billion gallon mark by 2010. The fuel can be made from soybean oil, palm oil, peanut oil, and other vegetable oils; animal fat; and even cooking oil recycled from restaurant French fry makers. Biodiesel also can be added to regular diesel fuel. It also can be a stand-alone fuel, used by itself as an alternative fuel for diesel engines.

Source: American Chemical Society

Explore further: How waste coffee grounds could help fuel London buses

Related Stories

How waste coffee grounds could help fuel London buses

November 21, 2017

(Tech Xplore)—Across continents, people are concerned about how to address harmful CO2 emissions in the environment. Now there is news that some London buses will run on a biofuel partially made from old coffee grounds. ...

Jet fuel from sugarcane a realistic prospect

November 21, 2017

The aviation industry produces 2 percent of global human-induced carbon dioxide emissions. This share may seem relatively small – for perspective, electricity generation and home heating account for more than 40 percent ...

Banning oil palm blocks good practices

October 13, 2017

Palm oil is not equal to palm oil: Since plantations differ massively in environmental and social criteria, a general ban of palm oil in biofuels, as recently discussed by the European Union, would punish the wrong producers ...

Bioreactors on a chip renew promises for algal biofuels

September 29, 2017

For over a decade, companies have promised a future of renewable fuel from algae. Investors interested in moving the world away from fossil fuel have contributed hundreds of millions of dollars to the effort, and with good ...

Recommended for you

Heavy oils and petroleum coke raising vanadium emissions

December 15, 2017

Human emissions of the potentially harmful trace metal vanadium into Earth's atmosphere have spiked sharply since the start of the 21st century due in large part to industry's growing use of heavy oils, tar sands, bitumen ...

A not-quite-random walk demystifies the algorithm

December 15, 2017

The algorithm is having a cultural moment. Originally a math and computer science term, algorithms are now used to account for everything from military drone strikes and financial market forecasts to Google search results.

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

Rick69
2.3 / 5 (3) Dec 12, 2008
There's no way the collection process of gathering these coffee grounds will be efficient enough to make this effort pay off!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.