THE PROBLEM
A suspected acid poisoning incident led to an unknown acid chemical entering the storage tank via the drainage system. This caused biological contamination, resulting in no gas production and poor gas quality—ultimately reducing production by 30%.
The tank was biologically inactive and deemed unrecoverable. If the issue was left, then the biogas from the fermenter feeding through to the end storage tank would have continued to cross contaminate, delivering poor quality gas to the CHP unit. This could have caused potential damage to the CHP, and unretrievable losses in production
THE SOLUTION
The solution was to isolate the end storage tank and maximise production through the digester to maintain plant output, whilst Circular Renewables carried out an outage on the end storage tank.
The works involved emptying and cleaning the storage tank which had been biologically contaminated from an unknown source.
Entering the tank provided the ideal opportunity to carry out
essential lifecycle maintenance, installing new stainless steel 316L mixer guide rail and turn head system. Complete a condition assessment of roof support structure, desulphurisation net and double membrane roof system
