Green Options

We’ve written here before about how to get composting and about how organic matter in landfills produces methane, a greenhouse gas that’s stronger than CO2. The average person in the U.S. drinks around 3 cups of coffee per day. Americans consume over 2.4 billion pounds of coffee per year. That leaves a lot of spent grounds that could be headed right for the trash bin.

Java City is doing its bit to make a difference with its Joe-to-Grow program. Folks can pick up spent coffee grounds to use as fertilizer for acid-loving plants. On top of recommending that you sprinkle them on your garden, the Java City folks say that used grounds make a great repellent for ants, slugs and snails. They also recommend drying out the grounds and then sticking them in the fridge or closet to absorb odors, just like baking soda!

So what are some other uses for spent coffee grounds?

Coffee grounds are beginning to seem like quite the multi-purpose substance. First we heard about the possibility of grounds being used as biodiesel, and now we’ve received word that the world’s first printer to use coffee grounds for ink is a contestant in Core 77 and Inhabitat’s Greener Gadgets Design Competition.

Researchers are reporting they have successfully made a high quality biodiesel from spent coffee grounds. They estimate that the coffee ground biodiesel industry could generate as much as $8,000,000 in profits annually using waste from US Starbucks stores alone.

One of the main limits to the acceptance of biodiesel as an alternative fuel is its price premium above regular diesel. To bring the price of biodiesel down, the industry uses as much waste material from other industries as possible to make it — such as used fryer oil and animal fats from poultry processing.

In holding with the idea of cheap biodiesel feedstocks, a team of researchers in the Chemical and Materials Engineering Department at the University of Nevada figured that maybe spent coffee grounds would fit the bill too.