Waste Management at the Sole Bay Brewery
|Adnams Plc spends tens of thousands of pounds annually to dispose of wastewater and waste beer, which both contain useful energy that could be harvested through anaerobic digestion. This dissertation examines the technical and commercial viability of onsite wastewate treatment. An additional investigation is made into other opportunities for Adnams Plc to cooperate with partner businesses to produce closed-loop resource cycles where the brewery waste products are used as an input to other processes.
The analysis of Adnams Plc’s waste streams has resulted in a bespoke waste management system, optimised for this application. Appropriate anaerobic digestion technology has been identified and a suitably sized combined heat and power generator has been sourced that will be powered from the biogas. Using anaerobic digestion, sufficient biogas is recoverable from the wastewater and waste beer to service 5% of the brewery’s energy requirements. Combined savings from wastewater treatment and energy generation will save 112 tonnes of CO2 emissions per annum and will save Adnams Plc around £63,000 per year; resulting in a payback period of eight years for an investment of approximately £500,000.
The opportunity has also been identified to farm mushrooms, using waste cardboard and spent grain as a growth substrate. There is an additional opportunity to operate a composting facility that will allow Adnams Plc to provide community gardens and to remediate an 85 acre gravel pit owned by Adnams Plc.
This investigation comes at an important time for distributed generation of electricity and shows that recent technological advances in both anaerobic digestion and combined heat and power generation have enabled the small-scale onsite treatment of wastewater. It also shows that government incentives for renewable energy have made AD viable for TSBB, which proves the effectiveness of current UK energy policy.