Sunday 21 October 2012

[Reposted] Anaerobic Digestion in Spain

The North London Waste Authority has said it wants to use either 'composting' or 'anaerobic digestion' at Pinkham Wood.

Link to a previous Channel 5 video on composting.

Here is a description of Ecoparc 2 de Montcada i Reixac, a Spanish 'Mechanical and Biological Treatment' plant, only slightly smaller than that intended for Pinkham Wood, and which uses anaerobic digestion:

Click above to enlarge image, and sometimes again to magnify
or link to a description of the plant in Spain.

"Feedstock: Mixed Municipal Solid Waste (presumably after collection of recyclables) and source-separated biowaste from Barcelona. [The NLWA has said that Pinkham Wood would not be a destination for separately-collected food waste.]

"Throughput: The facility full capacity is of 265,000 tonnes/year, or approximately 1000 tonnes/day. [The NLWA says Pinkham Wood would be for 300,000 tonnes/year.]

"Anaerobic digestion (AD): biodegradable material is converted by a series of bacteria groups into methane and carbon dioxide (CO2). Anaerobic digestion has been used for over a century to process sewage biosolids. If the MSW feed is processed in the solid phase, AD is often referred to as 'anaerobic composting'.

"The biogas produced can be used on site to generate electricity and heat using a generator (reciprocating engine, microturbine, conventional turbine, etc.). The biogas can also be purified extensively (dehydrating, H2S removal) to pipeline quality and pressurized, for example to be used as compressed natural gas (CNG), a safe and clean vehicular fuel.

"For every 100 tonnes entering the Ecoparc,
  • 45 tonnes are rejected in pre-processing [seemingly for 'packaged landfill' - Pinkham Wood 'Solid Recovered Fuel' would go for incineration at Brent Cross.]
  • 5 tonnes are recycled;
  • 8 tonnes are rejected in post-processing; and
  • 42 tonnes are converted to biogas and compost."


Click to enlarge image above
(or click here to see a map
- co-incidentally, this plant is also on the border of three local authority areas!)
By the way, 
one-third
of the London Borough of Barnet
is open countryside!

How's your Spanish?
('ecoparc' is Catalan; 'ecoparque' is Castillian!)

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