Anglian Water wanted to improve their
gas yields and energy production conversion
rates from their nine anaerobic
digester sites. They needed to combine
proficiency in digital twin software platforms
with expertise in wastewater plant
operations so they could undertake extensive
simulation modelling for treatment
centres.
The solution
Anglian Water worked with Aqua Enviro,
the SUEZ wastewater specialist
company. The Aqua Enviro experts employed
a process simulator, which combines biological,
chemical and physical process
models to accurately simulate the operation
and performance of Anglian Water’s
sludge treatment assets. The team drew
upon a variety of techniques, including the
use of BioWin based digital twins (Figure
1), to conduct an in-depth review. Using
a controlled environment enhances confidence
and limits implementation risk
on-site. The digital twin facility enabled
the team to identify improvements that
otherwise might not have been identified.
Figure 1: Building the model and asking the relevant questions at every stage
How it worked
1. Developed a good working relationship
with team at the utility company
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
The results
As well as the improved energy production,
the project successfully evaluated
conversion rates for different AD
processes (CAMBI, Monsal, HpH) and
identified the Anglian Water HpH process
as being industry-leading with
conversion rates of >1 MW/tds. Much of
what was achieved has been through operational
optimisation (i.e., without further
investment), around:
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
Differentiating factors
EXPERIENCE:
The Aqua Enviro team have decades of
wastewater treatment operational experience,
gained across UK and overseas
plants.
EXPERTISE:
Expertise in using digital twin BioWin
software, which is used worldwide to design,
upgrade, and optimize wastewater treatment
plants of all types.
COLLABORATIVE APPROACH:
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.
The future
The models developed by the Aqua Enviro
team can be reviewed and updated,
thereby used as a metric to evaluate,
and monitor the impact of improvements
made on site. New enhancements and algorithms
in the modelling programme now
extend to include emissions from digestate
(methane) and NOx from wastewater
treatment processes.
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