1. 4th International Conference on Advances in Energy Research (ICAER-2013)
Pinch Analysis for MultiDimensional Sustainable Energy
Systems Planning
Raymond R. Tan
De La Salle University, Manila, Philippines
Santanu Bandyopadhyay
Indian Institute of Technology Bombay, India
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2. 4th International Conference on Advances in Energy Research (ICAER-2013)
Classification of Design Activities
Qualitative
Heuristics Rules
Knowledge Based Systems
(rules of thumb)
(rule-based automated
approaches)
Automatic
Hierarchical
Analysis
Optimization Methods
Interactive
Thermodynamic Methods
(Mathematical
(Pinch Analysis, Exergy
Programming, Stochastic
Analysis)
Search Methods)
Quantitative
Process Integration and Optimization
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3. 4th International Conference on Advances in Energy Research (ICAER-2013)
What Is Process Integration?
Systematic and General Methods for Designing
Integrated Production Systems, ranging from Individual
Processes to Total Sites, with special emphasis on the
Efficient Use of Energy and reducing Environmental
Effects.
This definition points to design methods, but the term
Process Integration is also used to describe physical
arrangements such as the interconnection of
equipment and process streams in a plant.
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4. 4th International Conference on Advances in Energy Research (ICAER-2013)
Categories of Process Integration
Mathematical optimization based methodologies:
 preferred to address issues like multiple contaminants,
controllability, flexibility, cost-optimality
 a good synthesis tool in handling complex systems
with different complex constraints
 major problems associated with these methodologies
are combinatorial explosion and local optimality
 do not provide good insight to the process designer
during network synthesis
 do not exploit special structures of these problems to
develop efficient algorithm
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5. 4th International Conference on Advances in Energy Research (ICAER-2013)
Categories of Process Integration-2
Methodologies based on conceptual approaches:
 help in getting a physical insight through its graphical
representations and simplified calculation procedures
 efficient calculation procedure due to special structure
of these problems
 recognize the importance of setting targets before
design and allow different process design objectives to
be screened prior to the detailed design
 provides graphical representation tools and full control
to the process designer over decision making
processes
 applicable to simple systems with simple constraints
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6. 4th International Conference on Advances in Energy Research (ICAER-2013)
Pinch Analysis
Pinch Analysis is a conceptual process integration
approach
Development of simple and efficient algorithms by
exploiting special structures
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7. 4th International Conference on Advances in Energy Research (ICAER-2013)
Heat Exchanger Network (HEN)
Birth of Pinch Analysis
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8. 4th International Conference on Advances in Energy Research (ICAER-2013)
Problem Definition for HEN
 Given:
 a set of hot process streams to be cooled from the
inlet temperatures to the outlet temperatures
 a set of cold process streams to be heated from the
inlet temperatures to the outlet temperatures
 the heat capacities and flow rates of the hot and cold
process streams
 the external utilities available and the temperatures
or temperature ranges as well as their costs
 heat-exchanger cost data
 Objective:
 To develop a network of heat exchangers with
minimum annualized investment and operating costs
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9. 4th International Conference on Advances in Energy Research (ICAER-2013)
Historical Milestones




Ten Broeck, 1944: First known HEN-related paper
Westbrook, 1961: First use of mathematical programming for HEN
Hwa, 1965: First use of a superstructure in HEN
Hohmann, 1971: Composite curves to calculate of minimum
utilities requirement, and estimation for the minimum number of
units (attempts to publish in journals were turned down twice)
 Umeda et al., 1978 and Linnhoff and Flower, 1978: Identification
of heat recovery pinch point (Starting point for Pinch Analysis)
 Linnhoff and Hindmarsh, 1983: Pinch Design Method is proposed
 Furman and Sahinidis, 2001: Mathematical proof that this is N Phard (refuting the possibility for the existence of polynomial
optimization algorithms → Sequential optimization)
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10. 4th International Conference on Advances in Energy Research (ICAER-2013)
Process Flowsheet
20°
C3
1300
3
85°
Steam
1
155°
175°
Reactor
H1
1400
CW
40°
C4
Heat Duty
kW
45°
Steam
CW
125°
H2
1080
2
98°
112°
4
65°
1320
The starting point in the application of pinch technology is a
simplified flowsheet showing major unit operations with heating
and cooling duties.
Ref: U. V. Shenoy, Heat Exchanger Network Synthesis, 1995, Gulf Pub. Com., Houston, Texas
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11. 4th International Conference on Advances in Energy Research (ICAER-2013)
Temperature (°C)
Composite Curves
200
180
Process to process heat
160
recovery
140
120
Min.
100
Hot
80
Utility
60
Pinch
Min.
40
20 Cold
Utility
0
0
1000
2000
3000
4000
Enthalpy (kW)
5000
Composite Curves show the heat availability and heat requirement for
the overall process
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12. 4th International Conference on Advances in Energy Research (ICAER-2013)
Can We Target the Minimum Energy
Requirements in Algebraic Way?
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13. 4th International Conference on Advances in Energy Research (ICAER-2013)
“…some of the greatest advances in
science have come about because some
clever person spotted an analogy
between a subject that was already
understood, and another still mysterious
subject.”
- Richard Dawkins
The Blind Watchmaker (1986)
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14. 4th International Conference on Advances in Energy Research (ICAER-2013)
Brief History of “Pinch”
1970s
Synthesis of heat exchanger network (HEN)
1987
Synthesis of HEN for batch processes
1989
Synthesis of mass exchange network (MEN)
1994
Water minimization (water pinch)
2002
Property integration (property pinch)
2007
Energy planning (carbon pinch)
2007
Isolated energy systems
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15. 4th International Conference on Advances in Energy Research (ICAER-2013)
Basic Problem Pattern
 Minimize use of scarce, high-quality stream
 Each stream source has fixed quality and quantity
characteristics
 Each stream demand has fixed quality and quantity
requirements
 Quality index is inverse and follows a linear mixing rule
What other problems follow a similar pattern?
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16. 4th International Conference on Advances in Energy Research (ICAER-2013)
Source/sink representation
Source i
Source: A stream
which contains
the targeted
species. Each
source has:
Flowrate Fi
Quality Qi
Quality load:
mi = F i Qi
i=1
i=2
i=3
S Bandyopadhyay
Sink j
j=1
?
j=2
j=3
Sink: An existing
process unit/
equipment that can
accept a source.
Each sink has:
Flowrate Fj
Quality Qj
where:
Qjmin ≤ Qj ≤ Qjmax
Load capacity:
mi = F i Qi
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17. 4th International Conference on Advances in Energy Research (ICAER-2013)
Philosophy of Pinch Analysis
Generalized Problem Definition and Solution:
 Flows and Qualities
 Laws of thermodynamics, conservation relations
 Phenomenological relations, design correlations
 Overall optimization with system constraints
 Algebraic methodology
 Graphical representation
Setting Targets (Prediction of the optimum performance prior
to any synthesis/ detailed design):
 Physical insights to the designer
 Tool: preliminary analysis/directions for improvements
 Preliminary screening of design alternatives
 Step change to learning curves
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18. 4th International Conference on Advances in Energy Research (ICAER-2013)
Flows and Qualities in PA
Flows
Heat
Mass
Qualities
Temperature
Examples/Problems
Heat integration (1971, 1979)
Total site integration (1984)
Integration of thermal equipments (1982)
Mass integration (1989)
Concentration Water/Hydrogen management(1994,1996)
Pollution prevention/Treatment networks
Mass
Properties
Recycle/reuse networks (2004)
Steam
Pressure
Cogeneration (1993, 2008)
Energy
CO2
Carbon-constraint energy planning (2007)
Mass
Time
Supply chain management (2002)
Energy
Time
Stand-alone energy system (2007)
Isolated power system (2007)
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19. 4th International Conference on Advances in Energy Research (ICAER-2013)
The “PINCH” Concept
 Processes and Utility Systems
 From Scheduling to Strategic Planning
 Improving Efficiency (Energy and Raw Material)
 Continuous to Batch Processes
 All aspects of Processes: Reactors, Separators, etc.
 Integration between Processes
 Waste and Wastewater Minimization
 Emissions Reduction to Pollution Prevention
 Hydrogen Management
 Aggregate Production Planning
 Sizing Renewable Energy Systems
 ……… etc.
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20. 4th International Conference on Advances in Energy Research (ICAER-2013)
Sustainable Energy Systems
 Sustainable development meets the needs of the
present without compromising the ability of the future
generations to meet their needs (Brundtland, 1987)
 Sustainable energy systems provide energy services
to the present while ensuring that similar energy
services for future generations (Manish et al., 2006)
 Atmospheric CO2 levels recently exceeded 400 ppm,
(safe limit is 350 ppm, Rockstrom et al., 2009)
 Sustainability indices:
 Economic cost
 EROI: energy return on investment (Hall, 1972)
 Land/water/carbon footprints
 ….. etc.
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21. 4th International Conference on Advances in Energy Research (ICAER-2013)
Problem Definition
 Given a set of energy sources (i = 1, 2, 3… m)
 fixed EROI (EROIsi)
 cost per unit energy (Csi)
 carbon intensity or footprint coefficient (Fsi)
 availability limits (Esimax)
 Given a set of demands (j = 1, 2, 3… n).
 energy quantity (Edj)
 quality (carbon emissions) specifications (Edj × Fdj)
 Determine the source-sink mapping (system
network) using EROI and cost as objectives
 Multi-Objective optimization problem: Pareto optimal
front using weighted-objective method
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22. 4th International Conference on Advances in Energy Research (ICAER-2013)
Case Study: Philippines
Demand
CO2 limit (t/GWh)
Energy
Sources
Natural Gas
Coal
Geothermal
Hydroelectric
Wind
Others
Region A
17,500 GWh
500
Region B
5,000 GWh
200
EROI
Relative Cost
CF (kg CO2/kWh)
Limit (GWh)
7
18
15
40
20
6
1.14
1
1.67
1.19
1.67
5.71
0.55
1
0.17
0.04
0.03
0.09
No limit
No limit
3,000
10,000
1,500
350
Ref.: DOE, 2013; Evans et al., 2009; Gupta et al., 2011
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23. 4th International Conference on Advances in Energy Research (ICAER-2013)
Pareto Optimal Front
Relative cost Cost (Φ)
27000
Minimum energy invested solution
(EROI-23.47, cost - 26773)
Wind and hydroelectric at maximum, coal
(8958 GWh) and geothermal (2042 GWh).
26800
26600
26400
26200
26000
25800
25600
25400
25200
800
1000
1200
1400
Total Energy investment (Ω)
Mixed solution (EROI-17.78, cost - 25932)
Wind and hydroelectric at maximum, coal
(7233 GWh) and natural gas (3767 GWh).
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Minimum cost solution
(EROI-14.46, cost 25380)
Hydroelectric at
maximum, coal (5500
GWh) and natural gas
(7000 GWh).
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24. 4th International Conference on Advances in Energy Research (ICAER-2013)
Conclusions
 Pareto optimal front is piece-wise linear in nature
 Weighted objective methods can identify only discrete optimal
points (where slope of the Pareto optimal front changes)
 Line joining consecutive optimal point is also optimum
 Extended pinch analysis method for multiple-objective source-sink
problems
 Concept of prioritized cost (Shenoy and Bandyopadhyay, 2007)
can be extended to address multi-objactive pinch analysis
problems
 Demonstrated with a case study of Philippines
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25. 4th International Conference on Advances in Energy Research (ICAER-2013)
My father rode a camel. I drive a car. My son
flies a jet plane. His son will ride a camel.
- Saudi proverb
Thank You
santanub@iitb.ac.in
tanr_a@dlsu.edu.ph
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