Dr Misra says that a litre of biodiesel requires 5-7kg of coffee grounds, depending on the oil content of the coffee in question.

ECONOMIST: Monitor

The diesel-extraction method for coffee grounds is similar to that used for other vegetable oils.

ECONOMIST: Monitor

Commercial production could be carried out by a company that collected coffee grounds from big coffee-chains and cafeterias.

ECONOMIST: Monitor

In their laboratory his team has set up a one-gallon-a-day production facility, which uses between 19kg and 26kg of coffee grounds.

ECONOMIST: Monitor

Keyes is seen as a shadowy figure in ski mask and hood outside Common Grounds, a tiny Anchorage coffee shack then partially concealed from a busy six-lane highway by mountains of snow.

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The company's main product, a mushroom-growing kit, is a cardboard box that houses a plastic bag filled with coffee grounds and mushroom spawn.

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