I thought this was a fun one. Last month Science Daily reported that researchers in Nevada found that diesel oil could be recovered from used coffee grounds.
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.
U.S. diesel usage is around 40 billion gallons per year for on-road transportation, so at 340 million gallons, biodiesel from coffee grounds represents just a drop in the coffee cup. I wonder if it makes your exhaust smell like a Peet’s Coffee shop?