Thursday, January 22, 2009

Anaerobic Digestion: Marsian Expedition

An excursion to Lelystad, capital of Flevoland polder, led the Urban Waste Treatment class to an organic waste treatment plant: Biocel Fermentation Ltd. The excursion reminded the author of the silly comic by the Marsian author: Marsian Adventures to Stinkworld!! Ever read it?

Marsians walking down Reactor Hall of Fame

Orgaworld, like all other in the industry, claims to be a leader in fermentation of organic wastes and capture of methane. Biocel accepts green, over-date supermarket waste and industrial sludge and collects biogas from anaerobic decomposition of the organic wastes. 400,000 tonnes of organic wastes are converted into biogas, heat and compost per year.

In batches, organic waste is dumped in large reactors that operate a month at a time. A gi-normous door seals the deal, and allows for wastes to brew and ferment under deliciously stinky, oxygen-free conditions. Leachate is filtered from debris and recycled, retaining heat and nutrients for more deliciousness. Biogas is captured and converted into green power and heat (co-generation). The entire plant is run on electricity generated from this combustion, as well as 3000 more households.

The fermented material from the reactor is converted into compost via aerobic digestion. After a week, the compost passes through a drum, separating remaining plastics and solid debris from compost. Compost is mixed with a purchased high grade compost to upgrade the no-longer-stinky compost to a higher quality soil conditioner.

Digestate Waiting Room, heading for aerobic digestion

On a side-note, Albert Heijn is a top customer, and the supermarket chain dumps its over-date products at the plant. AH pays the plant to unwrap, because it be would unlawful to have fourteen year-olds unwrap molding food until 12pm? Besides, the plant is at an ideal location; far enough from civilization that the stench only affects the workers and the idiots who choose to visit.

Albert Heijn's supermarket wastes, and Prof Joost van Buuren taking care not to slip on slimy fermenting food.

Internship applications will not be submitted to anaerobic digestion plants.

Take my friends and me to Mars.