Optimised AD Plant Performance with OMEX

Tom Archard, owner of Castle Eaton Farm AD, in Wiltshire UK, has been operating his Biogas Plant since early 2014. The plant was designed by Frank Kenny of Water and Waste Services Limited based in Bath UK and utilises a CHP (Combined Heat and Power unit) of 0.5 MW. The Plant runs on a mixed feed of 8000 tonnes of maize, grass silage, cow/pig slurry and chicken manure a year.

The system consists of a hydrolysis tank, feeding into the primary 2000 M3 digester and onto a secondary 2000 M3 digester. The two digesters are recirculated and the residence time is 34 days.

After the initial 4 months using this mixed feed the system was running at 75% capacity. Over the next 4 months the yield dropped to 50%. This was investigated and action was taken to add 500 ml of OMEX Nutromex® TEA 310 daily (after analytical services provided by OMEX showed that the levels of some trace elements were low).

This improved the performance to 100% of the design specification producing 5770 Nm3/d biogas at 59% methane.

“OMEX provided an excellent, reliable and fast responsive service and I can recommend them to all biogas AD operators" - Frank Kenny, Waste and Water Services Ltd

Nutromex® TEA 310 was developed so that targeted addition of bioavailable trace elements could ensure an optimal biological process. These complex trace elements can on the one hand be absorbed more easily through an optimal binding site and on the other be protected from sulphide, carbonate and hydroxide precipitation. The effective formulation is non-corrosive, it is therefore safe to handle.

The addition of micronutrient additives such as Nutromex® TEA 310 is not new. Without the addition of these additives Biogas production would be considerably lower. The amount to be added will be determined by initial testing done by Omex Environmental in their fully-equipped laboratory and subsequent monitoring will ensure optimal use.

The advantage of Nutromex® TEA 310 is its high efficacy. For example for a 500 kW plant only 500 ml of Nutromex® TEA 310 is needed per day, which is an extremely cost effective method to optimize the performance of a Biogas Plant.