The word coffee arguably entered into English usage from the Dutch word ‘koffie’. Originating in Africa, coffee appeared in Europe in the 16th century and later spread to the Americas in the 18th century. Today much of the world drinks coffee, although consumption in the west remains higher than the rest of the world. Coffee is unique among beverages since its byproducts have unconventional uses.
Coffee grounds have found their way into London buses as biofuels. The idea is not new, as production of biofuels from coffee grounds can be credited to a team of researchers in the USA. But running the iconic double-decker buses in London from extracted biofuel is a cool implementation of this idea. According to sources, Londoners consume on an average 2 - 2.5 cups of coffee everyday which results in approximately 200,000 tonnes of waste every year. Coffee grounds can generate 20% oil by weight, therefore producing up to 6000 liters of oil. The oil mixed with mineral diesel forms the B20 biofuel blend used for fueling the buses. Much to the dismay of coffee lovers, it is noteworthy that London streets have not started smelling of coffee from the exhaust fumes.
Coffee grounds are also being used for water filtration. A researcher in Greece looked into using coffee wastes for removing heavy metals such as copper and chromium from water. Removal of other heavy metals such as lead and mercury by coffee wastes is in the process of being perfected by researchers in Italy. Coffee grounds can also be converted to activated carbon which can be used as air filters. Researchers in the USA are looking into coffee wastes as deodorizers since the nitrogen content in coffee can adsorb hydrogen sulphide from air.
There are many other uses of coffee grounds such as fertilizers and cleaning agents. But biofuel and filters stand out as the most potent of applications. In the past no one imagined coffee beyond a beverage. Today coffee is much more than the average beverage and we are perhaps not far from seeing vehicles running on coffee wastes in nations that lead in coffee consumption.