There is good news today about the development of UK commercial food waste anaerobic digestion with the announcement of a substantial UK government subsidy for a new food waste AD plant for the North East of England. Previously, little was happening in this region on food waste digestion, so this additional funding assistance should help to raise local awareness of the potential for waste treatment and diversion from landfill which food waste anaerobic digestion provides.
“Plans for the North East’s first-ever commercial food waste anaerobic digestion facility have taken a major step forward with the news that Emerald Biogas has secured an £850000 loan from WRAP. The North East currently creates around 800000 tonnes of …”
Just Why is the Anaerobic Digestion of Food Waste Worth Doing?
We thought that we would provide you with some of the current snippets of information out there in the news about commercial food waste AD. Firstly, it isn’t just the UK that has “discovered” this renewable energy source.
Food waste collected in the City of San Francisco, California, was characterized for its potential for use as a feedstock for anaerobic digestion processes. The daily and weekly variations of food waste composition over a two-month period were measured. The methane yields of the food waste were evaluated using batch anaerobic digestion tests and, as has been seen consistenlty elsewhere, the analysis showed that the food waste contained well balanced nutrients for anaerobic microorganisms. The methane yield was determined to be 348 and 435 mL/g VS, respectively, after 10 and 28 days of digestion. The average methane content of biogas was high as well, being measured at 73%. This methane yield is high, and food waste is thought of generally as the highest biogas yielding waste source available.
This means that the digester within a commercial food waste AD plant will produce more biogas per cubic metre of capacity than any other anaerobic digestion plant type. So, if anyone can make a profit from the investment in AD plant technology it will be the commercial food waste AD plant operator.
Do Commercial Food Waste AD Plants Tend to Run Out of Steam Eventually?
Early adopters who ran AD Plants some years ago reported that after more than a year of operation being fed by only food industry post production food waste their plant mysteriously “fell-over” (forgive the venacular expression – but it is an easily understood one!).
This was investigated through more than 5 years of ground-breaking research which was undertaken by Southampton University, UK, and which has resulted in the publication of research which conclusively demonstrates that such clean substrates as post production food waste do need some augmentation with specific rare earth elements. The effect of an insufficient presence of these elements only appears a long while after an initial reactor commissioning using WWTW sludge, when the trace elements initially bountifully found in sewage sludge become over-diluted over time.
Preparations are now available commercially to dose the reactor to prevent any long-term deterioration of commercial food waste AD plant performance.
Bristol is Also to Get its Own Commercial Food Waste AD Plant
In December 2011, a state of the art food waste processing facility that will have the capacity to receive up to 40,000 tonnes of food waste per year was announced to be under construction at the Bristol Sewage Treatment works, in Avonmouth.
Florida’s Municipal Solid Waste May Soon Also be Anaerobically Digested
Other Recent Commercial UK Food Waste Digestion Projects are Operational Already
But France Opened their First Commercial Food Waste AD plant in 2010…
However, according to the DEFRA archive, France may have gotten their full-scale food waste first! The first food waste digestion plant in France was completed in April 2010. Entec Biogas Gmbh was the designer, as well as general contractor for mechanical and electrical engineering and the process commissioning of the biogas plant. The biogas plant which is located in Benet treats waste from the food and animal feed industry.