Natural boost for AD plant efficiency is unveiled


A natural bioactive solution that can boost the quantity and quality of AD gas output while stabilising plants and reducing down time has been unveiled to the industry.

Citadel BioCat+™ is produced through the fermentation of natural plant material and long term testing in Switzerland and Germany has revealed a range of significant benefits in commercial and farm-scale anaerobic digesters.

During trials the amount of biogas produced was increased by an average 25% per tonne of feed stock, while the percentage of methane content was boosted from 54 to 62%. Odours were also eliminated as a result of the process cutting hydrogen sulphide levels by 75%, which also brings the benefit of reducing downtime due to the corrosive nature of H2S.

Plant operators have also demonstrated that power output equivalent to historic values could be achieved with 20% less feed stock when BioCat+ was introduced.

Citadel BioCat+, from ADBA member Citadel Environmental Solutions, is generated for introduction to a plant in a specially made catalyst production unit (CPU) installed on-site. The CPUs, which are wardrobe-sized cabinets, are manufactured from recycled material by a sister company of Citadel Environmental Solutions, Citadel Industries, based in Telford, Shropshire.

Managing director of Citadel Environmental Solutions, Ray Long, said:

We’re well aware that when any product appears on the market claiming to boost production or cut costs, in whatever sector, it can be met with a healthy dose of scepticism. That’s why we have extensively tested BioCat+ in real world commercial settings and now have valid and extremely positive results to demonstrate. We are confident enough that we can provide a guarantee to customers that if, after three to four months, they are not seeing results, they will pay nothing.


The benefits of introducing BioCat+ have been proven in both thermophilic and mesophilic digesters, the latter being the most common in the UK, and we have now introduced it to a number of units in this country, which are already showing the kind of results we would expect.

The micro-organisms in Citadel BioCat+ include naturally occurring bacteria from both land and marine sources and it is the synergy of the various components, combined with the biosphere it is applied to, which is returning the beneficial results. The cocktail, comprising microorganisms, micronutrients, cofactors and phages, has been developed through years of experimentation.

Mr Long added:

As numbers of AD plants grow in the UK the pressure is going to build on operators to make them as efficient and cost effective as possible. We know that Citadel BioCat+ will make a huge contribution to that through either increased output, reduced inputs or a combination of both – not to mention reductions in odours and corrosive elements of the process.

BioCat+ is also approved for use in digesters certified under PAS 110 and the Quality Digestate Protocol.

Posted in: ADBA News, Industry News, Members' press release, News for Members, Policy updates, R&D Updates

Tags: AD plant additives, efficiency, operational performance