AD Digestate Protocol Should Encourage Sales of Digestate

This protocol should assist the producers of AD Digestate massively to sell their digestate, if all goes well (Steve Last - www.anaerobic-digestion.com).

02-01-2009

Anaerobic digestion technology is expected to become more attractive to investors following the publication of a long-awaited Quality Protocol aimed at cutting red tape governing solid residues from the process, known as digestate.

The revised Quality Protocol is available now on the Environment Agency website

The revised Quality Protocol is available now on the Environment Agency website
WRAP, Defra and the Environment Agency have published a document which, subject to approval from the European Commission, will enable digestate which meets set criteria to be classified as a product rather than a waste. Such a move would mean the material would no longer be subject to waste management controls.

Anaerobic digestion is the process through which biodegradable waste is broken down by micro-organisms in the absence of oxygen. This process produces biogas, which can be used to generate energy, waste water and digestate.

The protocol is particularly significant because, despite government support for anaerobic digestion technology and its carbon benefits, there has been limited uptake of the technology in the UK to date - with marketing digestate one of the main sticking points.

Nick Bethel, policy advisor at the Environment Agency, told letsrecycle.com that
the protocol had been designed to "bring value into the resource" and one of its purposes was to create a "climate for investment". Mr Bethel added the EA was "expecting to see further investment and more AD facilities being built" thanks to the re-classification of digestate from a waste to a product.
Requirements

The Quality Protocol, which has been revised since an original consultation in April (see letsrecycle.com story) lays out a number of requirements for AD operators who want to produce "quality digestate" from biodegradable waste.

Digestate must be produced using source-segregated materials listed in the Protocol, such as municipal food waste which has been collected separately and specified food and animal wastes.

Significantly, the Protocol designates end market for the digestate. Those markets are:

• Agriculture
• Forestry
• Soil and field grown horticulture
• Land restoration
• Soil manufacture and blending operations
• Land reclamation

In all cases the digestate must be used in a way that does not "pose a risk to the environment" and does "not compromise the future sustainable use of the soil to which they are applied".

Waste operators must also keep strict records showing showing that digestate meets the approved standards and the Quality Protocol. AD operators must also obtain certification from an approved body such as the Association for Organics Recycling.

Before publication as a final document in England and Wales, the draft Quality Protocol must be notified before the European Commission's Technical Standards committee, which may take up to six months.

During this period, the Environment Agency will continue to regulate the production and use of quality outputs from anaerobic digestion of source-segregated biodegradable waste in accordance with the interim regulatory position statement available on the Environment Agency website.

A spokesman for Defra commented: "The Government recognises the potential of food waste to generate energy in an environmentally friendly way. For example, we are investing £10 million over the next three years into new anaerobic digestion demonstration plants to encourage a number of industries including energy providers to take up this important new technology."

German Anaerobic Digestion Technology Supplier Enters UK and Irish Markets

UTS Biogastechnik is now also in UK & Ireland

Foundation of UTS Biogas Ltd.

The UTS Biogastechnik Group of companies were extended into the United Kingdom and Ireland by a new subsidiary on December 1, 2008.

UTS Biogas Ltd., with Rob Heap as General Manager, is located in North Yorkshire, near Scarborough and will provide full support to biogas markets in the United Kingdom and Ireland. Rob Heap has many years of experience in the agricultural and allied industries.

The CEO of the parent company, Dr. Andrew Benedek, said:

"It is now the right time to enter this very interesting and rapidly expanding market. Government plans to support renewable energies are well developed and already the first bills have been accepted by Parliament. It is our belief that this act will certainly help with climate change and, most importantly, will also significantly help local environments by turning waste into energy."

From the German perspective they view the biogas sector in the UK as hardly developed – compared with other European markets.

First developments show that mostly small – medium output plants are appealing to potential customers.

UTS has over sixteen years experience in building reliable plants in this range and they believe that they have a lot to offer the UK market as they can also support the developing UK AD market as the plants in the larger megawatt ranges become important.

With the full support of the parent company situated in Germany, Rob Heap and the UTS team want to offer their future customers a total-solutions concept including feasibility, planning, design & build, operating, training and complete after-sales support following hand-over of the plant.

Rob’s view is that:

“With the vast experience, flexible approach and advanced technical standards of UTS-products, we can deliver more reliable plants and comprehensive supporting services to the UK & Irish markets than those that have been available before."

Further information can be obtained at their website: www.uts-biogas.com

Is Anaerobic Digestion a Good Way to Treat Landfill Leachate?

Every now and again the question of whether landfill leachate can be effectively treated by Anaerobic Digestion is raised.

My reply is yes, and in fact, it has already happened in the landfill before you usually see most leachate. After an initial aerobic (acetogenic) stage, modern landfills in effect become anaerobic digesters themselves. Once this has occurred the leachate produced has already been subjected to a form of anaerobic digestion, so there is little additional treatment which an AD Plant can provide to these mature leachates once leachate is removed from the landfill.

In a modern Municipal Solid Waste (MSW) landfill. as it is filled, each cell or area within it, will within 6 months to one year, or, at the most eighteen months, not only become airless, but methanogenic (methane producing). Once this happens, the decomposition process taking place in the landfill is broadly similar to, but slower than, that which occurs in an anaerobic digester.

So, modern lined and well regulated landfills these days do, almost without exception, produce a mature methanogenic leachate.

As a result the use of Anaerobic Digestion to treat landfill leachate is not normally a good choice and the use of the Anaerobic Digestion process to treat landfill leachate is not very effective. This can be readily deduced just by thinking about the processes which leachate undergoes within a landfill. The big problem with using AD on a mature leachate would be the lack of significant reduction of ammoniacal nitrogen in the discharge, and ammoniacal nitrogen is one of the most important contaminants to remove, for reduced toxity to water life.

However, the opposite does work. Now think of using aerobic reactors to treat Anaerobic Digestion concentrates, if these concentrates cannot for any reason be disposed as a fertiliser product and thus have to be treated as a waste material.

So, leachate treatment plant aerobic biological reactors can be used very effectively to treat AD liquid digestate, if that "product" ends up proving to be unsaleable locally. Indeed, on site aerobic digestate treatment might be essential in these circumstances if no sewage treatment works was available to accept tanker loads of liquid from an AD Plant.