Coffee grounds may be able to provide energy beyond the caffeine buzz most drinkers seek, according to a study appearing this week in the Journal of Agricultural and Food Chemistry. The study's authors claim that the oil contained in grounds, when extracted, could produce as much as 340 million gallons of biodiesel per year. ScienceBlogger Greg Laden ponders what will happen when coffee goes to make diesel instead of lattes.
back of envelope calculation
I'm a heavy coffee drinker.. so I run through maybe a pound a week ... how much viable oil in that pound of coffee?
Anyhow, diesel fuel weighs about 7 lbs/gallon, so even at 100% conversion that coffee will produce 1/7 gallon of fuel... You can burn that in a few minutes
Nice idea, though I imagine it's going to be pretty impractical to gather enough coffee grounds.