Turning waste water into fuel

From Sowetan Live:

MATAGALPA, Nicaragua – That morning cup of coffee gives many of us a needed boost, but Central American coffee farmers have found a new source of energy in their beans: turning agricultural waste water into biogas.

An often overlooked by-product of the world’s favourite stimulant, the water used to process raw coffee beans is usually dumped back into the environment untreated. In Central America, locals call it “honey water” because of its sweet taste and yellowish colour.

Extremely polluting, it is high in methane gas – a leading contributor to global warming produced, in this case, by the fermentation of the coffee tree’s berries.

Across Nicaragua, the 1.3million sacks of coffee produced annually generate pollution equivalent to about 20000 cars. Now a pilot project at 19 farms in Nicaragua, Guatemala and Honduras is treating that water, separating out the methane and using it to fuel electric generators.

“Look how high that flame is,” said Sarahi Pastran as she…

Read more: http://www.sowetanlive.co.za/news/2014/12/13/turning-waste-water-into-fuel