Maximising renewable energy generation from anaerobic digestion
Figure 1: Building the model and asking the relevant questions at every stage
2. Understood the specifics of each of the AD processes at all nine sites. The process flow schematics for the individual sites were developed and then the operational parameters were incorporated
3. Replicated each one with a digital twin. The trained technicians use their knowledge of the Envirosim BioWin software to create the replicas (Figure 2)
4. Validated the replicas in coordination with the Anglian Water team. This involved data collection and sampling over three weeks to calibrate and validate the model
5. Adjusted all the potential parameters. Once modelled, a range of dynamic simulations with various operational considerations and scenarios were conducted to identify key areas for improvement to enhance power output (Figure 3), bespoke for each site. Understanding of the subtleties of wastewater treatment plant operations is a distinct advantage here. The team:
a) Questioned and reviewed every stage of operations
b) Established the capacity of each
type of sludge to generate energy
c) Understood the conversion rates
for each type of AD process (CAMBI, Monsal, HpH)
6. Repeated this process multiple times to find the solutions that cost the least but gives the most benefit
7. Identified the optimal list of operational improvements for each of the nine sites.
Figure 2: The BioWin model
- better sludge conditioning
- better management of thickening process efficiency
- control of mixing sludges
The modelling pointed to the need for improved process control, monitoring and better mixing, all of which have contributed to enhanced performance and output.
✓ Improved operational efficiency
✓ Higher gas yields
✓ Improved energy output
|✓ Raised awareness of operating factors to improve conversion rates|
Figure 3: Outputs
The Aqua Enviro team have decades of wastewater treatment operational experience, gained across UK and overseas plants.
Expertise in using digital twin BioWin software, which is used worldwide to design, upgrade, and optimize wastewater treatment plants of all types.
The Aqua Enviro team collaborated with the client, helping to mitigate risks around KPIs and business targets, reducing operational costs from chemical consumption and enhancing energy output and revenue.
A retrospective view of the project demonstrates that BioWin modelling is an invaluable enabler of innovation and optimisation at a strategic level. Given the complexity of the task of comparing efficiency on multiple integrated STCs, BioWin, along with the framework developed with the team at Aqua Enviro, is a powerful tool in providing successful efficiency gains and process insights.
David Inman , Innovation Projects Manager, Anglian Water