In the UK Food Waste Anaerobic Digestion Plant History began with the dedicated Food Waste AD Waste Technologies Demonstrator Plant, known as the Ludlow Digester.
In the UK the history of dedicated food waste anaerobic digestion plants began there in 2004, when the innovative government funded plant opened.
At the time, nobody was sure that dedicated AD plants for food waste alone, could be made to run reliably for long periods.
But there was pressure to develop new waste technologies. There was a need for action due to increasing public awareness that the amount of the nation’s food being binned and disposed to landfill, was unacceptable.
Food waste which had been rising for many years, had become a major problem to dispose of.
UK Food Waste a National Scandal
Many people see food waste as scandalous when so many people go hungry.
That’s without even considering the waste of resources.
Plus, it doesn’t even need to be said, that food wastage creates enormous unnecessary environmental damage! We are producing so much food which never gets eaten.
At that time over 62% of all waste was being sent to landfill (Defra Report – Advanced Biological Treatment of Municipal Solid Waste, 2007).
Food waste adds greatly to the strength of the dirty water (leachate) in any landfill. This in-turn raises the danger to groundwater around landfills, if the landfill ever leaks.
That has not changed but thankfully much more waste is recycled or incinerated, and only about 20% is landfilled currently. Nevertheless, food waste recycling in England is a long way behind rates achieved in Scotland and Wales, and has been described as a scandal.
In the autumn of 2018, the UK government published a new 10 year waste strategy. That states that the Government will require all local authorities in England to collect and treat food waste from all households in England. At the time of writing, almost 1 year on, no further progress has taken place to implement this policy.
Food Waste Anaerobic Digestion Plant History Demonstrator Project
Back in the years before 2006 studies by consultant Aspinwall & Company, as advisers to Defra, had revealed that anaerobic digestion with it’s output of biogas, was the best option for treatment of inedible food.
Aspinwall had reported in general that:
Biogas production by means of anaerobic digestion (AD) enables the full nutrient cycle
AD should thus be recognised as the preferred method of food waste recycling
In addition to renewable energy production, AD provides another valuable product, digestate that is able to replace mineral fertilisers as an organic fertiliser.
The nutrients included in the AD feedstock (food waste and other biodegradable waste, agricultural residues etc.) are not lost during the digestion process
Nutrients are thus conserved in the remaining digestate
Spreading digestate on agricultural land brings the nutrients back to the soil and enhances the production of food crops and consequently raises food security.
This was accepted by the Labour government of the time, and it was decided that in order to move UK waste management practise forward the government would provide grants for several demonstration projects.
One of those was for a Food Waste Anaerobic Digestion Plant to be built and commissioned and the resulting data to be published.
Viability of Dedicated Food Waste AD First Proven by the Defra Waste Treatment Demonstrator Project
The Defra Demonstration Projects were tendered and Biocycle (successor company is “Biogen”) won the design build and operate contract, which was built on a site in Ludlow in Shropshire.
When work started there was doubt whether AD plants fed solely on food waste were viable, as a number of attempts had failed. Thankfully, ground breaking research at Southampton University showed that food waste digestion was possible, all that was needed was for the operator to add small amounts of trace compounds which are lacking in food.
Ludlow Digester a Success
The Ludlow Biocycle digester was a successful biogas plant, albeit that lessons were learnt. One such lesson was the need for efficient grit removal from the digester even for food waste.
The closure of the plant in 2012, should be seen as much more to do with local authority cutbacks due to austerity measures put in place by the Conservative government elected in 2010, than any other factor.
Food waste digestion was, and still remains, expensive. Shropshire County Council was charged a gate fee by Biocycle, and had the additional expense of:
food waste collection from households and
transport to Ludlow.
It was unsurprising that it closed.
Our original closure article follows:
Original Article:Published in September 2012
UK’s First Food Waste Anaerobic Digestion Plant as a Defra Demonstrator Project to be Shut
Sadly, Shropshire Council and Biogen have announced the closure of the Biocycle food waste anaerobic food digestion (biogas) plant in Ludlow.
Back as far as 2010 the Council were looking at stopping household food waste collections in the area as a reaction to the need to cut finances although this isn’t stated to be a reason for the plant’s closure.
The decision has been made to wind down plant operations in the course of September with the full closure of the plant by the end of 2012.”
It would certainly seem that while it was by all accounts a technical success, the site was definitely too smal to be economically viable, and local CHP use of the waste heat had not been implemented which would have added to revenue, plus the site is fully used and presumably not suitable for expansion.
The 5,000 tonne per annum plant, built in 2005 as a non-commercial operation at a time when many in the UK questioned the viability of such plants for household waste, and was set up with financing from DEFRA and Advantage West Midlands.
Biocycle currently services a few contracts outside Shropshire, but reportedly there are now other AD plants which can process this waste.
Take a look at the following article for more information:
UKs first demonstrator food waste anaerobic digestion plant closed…
“Shrewsbury UK Shropshire Council and Biogen have jointly agreed to cease operation of the Biocycle anaerobic digestion AD plant at Coder Road, Ludlow.”
via [Recyclingportal.eu – Link no longer available]
Ludlow Food Waste History and the Present
By raising local awareness and using local expertise in food waste anaerobic digestion a locally funded community digester was built which lives on and continues the history of biogas production in the small Shropshire Market town of Ludlow.
This plant is an innovative plug-flow type biogas plant. So, it is fair to record that UK food waste anaerobic digestion history continues to be made in Ludlow.
The facility in Ludlow, Shropshire was a Defra “New Technologies Demonstrator” plant.
The following design information is provided from the Defra Report, Advanced Biological Treatment of Municipal Solid Waste, 2007, Page 15:
“[The AD Plant] was designed to treat 5,000 tonnes per year of source separated garden and kitchen waste.
The input waste undergoes two shredding/wetting stages before being placed into a feedstock buffer tank. This feeds the AD tank, which uses a uses wet mesophilic (37ºC) AD process in a fully-mixed tank.
The AD process is continuous with a batch pasteurisation process (70ºC for one hour) at the end to meet ABPR requirements.
The digested material is then separated into digestate (>0.5mm) for use as a soil conditioner, and liquor to be used as a biofertiliser.
The biogas produced fuels a combined heat and power (CHP) unit, to produce renewable electricity for the grid and process heat available for district / local heat needs.
When operating at full capacity, the net electricity production is estimated to be 1.5 million kWh and a net heat output of 2.2 million kWh.”