Project Appreciation and Objectives
Energy recovery from anaerobic digestion of sewage sludge (and other solid wastes) is a high profile process to recover value and meet carbon reduction commitments. Well stabilised biosolids allow efficient and hygienic recycling. Inefficient operation of digesters results in significant revenue losses due to sub-optimal biogas production and reduced CHP output.
A variety of monitoring and measurement procedures and locations are currently used to manage digestion. Consistency in comparative and benchmarked analysis of these data would identify process and energy production efficiencies, deficiencies and imbalances.
Based on best practice digester operation principles, this project will develop a biogas energy production optimisation tool to calculate energy and mass balances. Using available data it will identify potential for operating improvements and opportunities for maximising biogas production and CHP performance, with assessment of associated impacts or requirements within the treatment works. The tool will support analysis of site performances across the organisation and, with calibration, a detailed analysis of individual sites. It will allow addition of modules to extend boundaries to transport or other biosolids processes.
Benefits to Clients
- Determine energy production capability of digester CHP installations.
- Assess current energy and biogas production against achievable targets.
- Identify reasons for shortfalls in energy production.
- Enable reconciliation of mass balances.
- Highlight operational changes required to achieve maximum energy production capability.
- Specify boundaries of processes, set benchmark relationships, specify outputs.
- Assess capabilities of measurement, monitoring and analytical devices and methods.
- Create and test optimisation model.
- Prepare and demonstrate finished tool.
- An energy production optimisation tool that calculates current CHP and digester performance, highlighting operational changes needed for maximum biogas production.
- Detailed guidance on use of the optimisation tool and review of monitoring methods.
- Pumps - Optimisation & replacement, CP348a, 2009-ongoing
- Comparing Energy Efficiency: Where are we good?, CP310, 2006-ongoing
- Digestion plant - performance analysis, model and desk based assessments, UK Water Utility, 2008
- Adaptation of current IWA digestion model for food waste input, in association with Imperial College, 2009
- Carbon Accounting and Sustainability workbooks prepared for water industry, UKWIR, 2008