Filip H.A. Claeys, DHI Software Products, Denmark
Optimizing industrial water networks with the WQMT
Henrik Birch, DHI Solutions, Denmark
Mónica de Gracia, ATM / Praxair, Spain
René Jurgens, TNO, the Netherlands
Izaro Lizarralde, CEIT, [email protected]
Filip H.A. Claeys, DHI Software Products, Denmark
Optimizing industrial water networks with the WQMT WESTforINDUSTRY
Henrik Birch, DHI Solutions, Denmark
Mónica de Gracia, ATM / Praxair, Spain
René Jurgens, TNO, the Netherlands
Izaro Lizarralde, CEIT, [email protected]
WESTforINDUSTRY ?
3
• Software framework for representing and solving water quality issues in industrial water networks
• Currently still under development in the scope of the AquaFit4Use project
• Previously known as WQMT - “Water Quality Management Tool”
• Based on DHI’s Tornado engine, and user interface modules from the WEST commercial WWTP modeling & simulation tool
• Prototypes used by project partners in support of case studies
Questions answered ?
4
• What is effect of...
– ... changes in network topology?
– ... changes in discharge limits?
– ... changes in water source quality?
– ... changes in treatment options?
– ... changes in industrial processes?
– ... changes in operational parameters?
– …
Objectives ?
5
• Management of information on water network blocks
– Behavior
– Constraints
• Creation of visually appealing graphical layouts of water networks
• Simulation of water networks
– Computation of flows & component concentrations
– Computation of objectives on the basis of data aggregation
– Check for constraint violations
• Optimization of water networks
Competing tools ?
6
Spread-sheets
Pinch Analysis
Process Simulators
WEST for INDUSTRY
Network topology � �
Simulation � � �
Optimization � � (�) �
Intuitive � � �
Specialized � �
Realistic models � � �
Openness � � (�) �
AquaFit4Usemethodology
�
Model Representation
9
• Static representation of behavior and “cost” (objectives)
• Specification in Modelica language
– Popular product-independent modeling language
– Object-oriented
– Based op equations
• Final models are programmatically composed on the basis of automatically generated sections and custom sections
• Models can be linked to external code for computing chemical equilibria (cf. pH):
– Automatically generated dedicated custom C code
– PHREEQ-C engine
Simulation
10
• Set parameters
• Select subset of components for output
• Execute simulation
• If needed, efficient executable model is created silently
• Results
– Flows & component concentrations
– Objectives (investment cost, operational cost, …)
– Constraint violations
Optimization
11
• Principle: automatic evaluation of predefined alternatives
• Determine optimization variables
– Selection of parameters
– Specification of values for each parameter
• Manually
• Automatically through spacing between bounds or samplingfrom statistical distributions
• Generate runs for all combinations of parameter values
• Optionally: Manually add / remove / modify runs
• Execute runs & perform ranking according to objectives
Optimization
12
• Typical ranking
– Grouping on basis of numerically erroneous / error-free runs
– Grouping on basis of number of constraint violations
– Sorting on basis of objective values
• Selection of run that has no numerical errors, least number of constraint violations and best objective value
• Export of results to text or Excel file for post processing
WESTforINDUSTRY vs. WEST ?
13
WESTforINDUSTRY WEST
Focus Industrial networks Domestic wastewater
Model type Static Dynamic
Modeling language Modelica MSL
Model definition At run-time A priori
Component definition At run-time A priori
Range definition At run-time A priori
Model repository Central, Local Local
Complex experiments SA SA, PE, LSA, GSA, UA
Output Tables Tables, Plots
Visualization on layout Yes No
Case studies
14
• Generic
– Benchmark Water Network
• Food Industry
– Unilever - Ben & Jerry’s (Hellendoorn, NL): Ice cream factory
– Alpro (Wevelgem, B): Soya products plant
• Paper Industry
– Holmen (Madrid, E): Recycled paper production plant
• Chemical Industry
– Perstorp (Perstorp, S): Polyol production plant
Case study: Unilever - Ben & Jerry’s
16
• Situation
– Construction of Anaerobic Digester for treating waste water
– Construction of Living Machine (ponds with plants) for treating waste water
– Questions about potential use of rainwater as alternative water source
• Scenarios
– Discharge of Living Machine effluent to surface water (river Regge)
– Use of Living Machine effluent in cooling tower
– Use of rainwater in transport washing
– Use of rainwater in toilet flushing
– Use of Living Machine effluent in COP processes
Case study: Unilever - Ben & Jerry’s
17
• Conclusions
– Living Machine effluent can be conditionally discharged to river
– Infiltration is possible with Living Machine effluent
– Chemicals and salt content of the CT can be bottleneck for infiltration
– Softening of groundwater is needed for use in the CT
– Living Machine effluent can be conditionally used in the CT and in COP processes
– Treatment of rainwater is required for use in transport washing to prevent growth of bacteria
– Rainwater can be used in toilets
Case study: Alpro
19
• Situation
– Water used from 3 water sources with variety in composition, most notably in hardness
– Water softened by ion exchangers and reverse osmosis
– Softening requires frequent regeneration of resin
– Currently leading to precipitation problems
– Water re-use is desired in general
• Scenarios
– Less extensive softening
– Softening with FACT
– Use of WWTP effluent for DWS processes
– Use of WWTP effluent for cooling towers
– Use of sealing water in DWS processes
– MBR treatment
Case study: Alpro
20
• Conclusions
– 85-89% softening is sufficient for the soft water processes for respectively 27 °F and 45 °F city water. The steam boiler requires > 97/98% softening which can be done by a dedicated softener.
– Bypassing the IX regenerate and RO concentrate at the WWTP will drastically reduce the chances of scaling in the water system.
– The required softening of the city water for the DWS processes can be achieved using FACT.
– MBR treatment is needed to make the WWTP effluent suitable for use in the DWS processes
Case study: Alpro
21
• Conclusions
– Reuse of the WWTP effluent in the cooling towers is possible for the 27 °F city water at 90% softening. For 45 °F city water near 100% softening is needed (not realistic).
– The sealing's effluent can be used in the DWS processes.
– No pathogens (Legionella, E-Coli, Enterococci) were found in the various water streams.
– The WWTP effluent also does not contain any pathogens. However, to ensure safe use in all cases disinfection before reuse is strongly advised.
Gravity table
Sludge
PM 62
DAF 1
LOOP 1
DAF 2
Product
DAF 3
Cooling
tower
Effluent
MBBR3
DAF 4
Evaporation and
losses
LOOP 2
Water steam
MBBR1
Cooling
processes
MBBR4MBBR2
Clean water
Process water (<1g/l)
Product line
Waste line
2 3 4
5
6
7
8
9
10
11
12
14Storage
Boilers
Cooling
water
tank
13
De DIP2/3
1Drum
Pulper2'
Case Study: Holmen
Case Study: Holmen
( )
NKQ
NQQTSS
NOP
LS
NIC
COST
FW
w
ww
treati
i
treatnewi i
i
·365···411.1
·365··1510
··200
·365·
·
6+
+
+
+
=
∑
∑
=
=
Investment
cost
Operational
cost
Cost associated with
sludge treatment
Drinking
water
Case Study: Holmen
ConceptScenario 1 Scenario 2 Scenario 3
IC (€) OP (€/d) IC (€) OP (€/d) IC (€) OP (€/d)
Drinking water --- 19754 --- 7986 --- 6451
Sludge production --- 156219 --- 158227 --- 140568
MBBR --- 955 --- 955 --- ---
DAF --- 53 --- 53 --- ---
UASB --- --- --- --- 2593192 34
MBR --- --- --- --- 3643882 229
RO --- --- 832085 566 1110224 188
UV --- --- 195065 160 189863 156
Total cost in 20 years 1291.9 M€ 1227.0 M€ 1085.2 M€
Conclusions
30
• WESTforINDUSTRY is a powerful tool for the optimization of industrial water networks described by detailed static models
• It combines features separately found in other tools, under the hood of a modern and visually appealing user interface
• Cases in various industrial sectors have demonstrated the usefulness of the tool
• Tool is mainly interesting for consultants performing full-fledged case studies, or for end-users (industries) doing smaller scale scenario analyses and/or for communication between experts and management
• DHI will carry WESTforINDUSTRY further commercially after conclusion of AquaFit4Use project