Wednesday, March 10, 2010

Make Digestate from Source Segregated Biowastes Using PAS110 and it isn't a Waste Material

The new PAS110 protocol is good news for those Anaerobic Digestion Plant operators that utilize a solely green waste (eg source segregated garden waste) feed source because UK regulators have been confirming this month that within a set of specific criteria they will not apply formal waste regulatory controls to these digestates.

The suitable waste input list includes:
  • Source segregated biowastes
  • Biodegradable non-waste materials
  • Allows for packaged biowaste.
(See Nina Sweet link below)

This is great news. It means that it is then much easier to use this material as for example a fertilizer, and spread it on land.

When any material is designated as a waste, it is not only the additional burden of the regulatory measures themselves which are essential for compliance with the Waste Regulations. It is also the cost of additional record keeping and monitoring, plus the Waste License fees, which are a big negative for potential users and sellers as well.

I imagine that it will especially help farmers who take in green waste from the local council and wish to produce biogas from it in on-farm digestors.

PAS110 is known as the Quality Protocol for Anaerobic Digestate and it was published in its final form January 2009. In the last few weeks it has received approval by the European Commission.

This reclassification of this type of digestate as a product and not a waste, will no doubt prompt a new generation of biogas digesters of the best kind, using green waste biomass rather than food crops.

The BSI PAS 110 safety standard is however, not entirely free of constraints and there are costs in the necessary monitoring required by the standard to assure the high quality of digestate produced from these biogas digesters.

More information is available at:

The WRAP Anaerobic Digestion PAS110 Guide download page

SEPA Waste regulation web site (Scotland)

AD Centre Wales PAS110 features Nina Sweet's document

Let's Recycle's Anaerobic Digestion page (scroll to the bottom)

1 comment:

Anonymous said...

Yes it is a useful development. BUT it should not be considered a panacea, achieving PAS110 requires energy and administration. There is also as yet no particular value in the diegstate, as trasnport costs are significant.
There is also the point, of course, that gas yields are key to the economiocs of a biodigester, and that in turn means that green waste is of limited utility. And the moment you go to higher yielding stocks, such as source segregated food waste, ABPR and Pasteruisation kick in.
There are no simple get rich quick schemes in anaerobic digestion, much as some manufacturers and consultants would have one believe. AD is a high capital expenditure, allied to a slow payback [laregly reliant upon double ROCs] and signififcant management costs.