Methane – hybrid orbitals

Biodegradation is nature’s way of recycling wastes, or breaking down organic matter into nutrients that can be used by other organisms. “Degradation” means decay, and the “bio-” prefix means that the decay is carried out by a huge assortment of bacteria, fungi, insects, worms, and other organisms that eat dead material and recycle it into new forms.

What’s the problem?
supermarket to be powered entirely by its own food waste – rotten food is picked up from Sainsbury’s stores and fed into an anaerobic digester. Within the zero-oxygen environment inside that digester, bacteria break down the waste to produce bio-methane gas. That gas is then used to produce electricity to meet all of one store’s day-to-day needs, allowing the building to operate independent of the electrical grid. Any extra electricity that’s not needed by the store, however, will be fed into that grid.

  • Ask – How could food waste be used economically? What can it be used for?
  • Imagine – What kinds of treatment options are available for processing organic matter like rotten fruit and vegetables? What would be produced as a result? How much will the processing cost? Is it worth the effort?
  • Design, Build – How can the waste be transported to the processing facility without adding more driving and more cost? Where is the processing facility located? Is there a nearby store where the electricity generated can be used?
  • Improve – How can any surplus electricity be used? Can the whole process be streamlined and improved to make it more cost effective?

That’s engineering

  • anaerobic – does not need oxygen
  • methane – a hydrocarbon that is a gas at room temperature (20°C). It is often found as the main part of natural gas. It oxidates carbon dioxide and water.

Engineering ideas

  • anaerobic digestion, bio-methane, degradation, bio, material

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