Heat Integration A short description with illustration case study Department of Process Integration, UMIST Manchester, UK

Heat Integration HEN Grassroot Retrofit Analysis 60  C 40  C50  C 100  C H1 C1 HE

Process Integration Developed and pioneered at DPI UMIST Gradually being established in industrial applications needs to penetrate into municipal etc DPI UMIST has a consortium of 26 world leading partners in the field It is supported by research SW Latest research in combined Water & Energy savings

Heat Integration Typical energy saving 15 – 45 % Very general – easily applicable in Power generation, Oil refining, Petrochemicals, Food and Drink Industry, Pulp & Paper, hospitals etc Typical pay-back periods from a few weeks to 16 months (decision made by the client) Considerably contributes to Emissions Reduction including CO 2

Some PI Consortium Members BP Degussa Mitsubishi Air Products Saudi Aramco Exon Mobil AspenTech Sinopec Norsk Hydro Shell IFP Eng of India CANMET TotalFinaElf JGC Corp UOP MW Kellogg BOC

Demonstration Example Most present applications are not grass-route but retrofits Considerably more difficult constrained problem Economy dictates the energy saving potential by pay-back period

Retrofit of HEN Crude Distillation Unit Part of a Romanian refinery complex Designed some years ago by a well known contractor Improvement of efficiency and energy consumption & economic savings

Process Integration Analysis Introduction Objectives Process Integration Analysis Conclusions Acknowledgements PINCH ANALYSIS SUGGESTED DESIGNS DATA COLLECTION SIMULATION EXISTING PROCESS RETROFIT ANALYSIS Process Integration Analysis EXISTING PROCESS

Preheat Train Crude Oil Kerosene Atmospheric Tower Medium Naphtha Vapour Naphtha Stabiliser Light Naphtha LPG (C2 - C5) Vapour Vacuum Residue HVGO LVGO Vacuum Tower Vapour LAGO HAGO Diesel Atmospheric Residue Denaphtha Tower Vapour Denaphtha Oil Naphta Steam Kerosene

Process Integration Analysis Introduction Objectives Process Integration Analysis Conclusions Acknowledgements PINCH ANALYSIS SUGGESTED DESIGNS DATA COLLECTION SIMULATION EXISTING PROCESS SIMULATION RETROFIT ANALYSIS SIMULATION Process Integration Analysis

Plant measurements & HYSYS Peng-Robinson property package Main source of data Existing HEN Energy consumption

112.8  C 92.4  C  C  C  C  C  C  C 90  C 70  C 40  C 50  C 210  C 90  C 20  C  C  C 220  C 348  C 110  C 350  C 370  C  C 63.2  C 144  C 315  C  C  C  C 63.6  C 69.1  C  C 60  C 150  C 76.8  C  C  C H1 H2 H3 H4 H5 H6 H7 H8 H9 H14 H13 H12 H10 H11 C1 C2 C3 C4 C5 C6 19

112.8  C 92.4  C  C  C  C  C  C  C 90  C 70  C 40  C 50  C 210  C 90  C 20  C  C  C 220  C 348  C 110  C 350  C 370  C  C 63.2  C 144  C 315  C  C  C  C 63.6  C 69.1  C  C 60  C 150  C 76.8  C  C  C H1 H2 H3 H4 H5 H6 H7 H8 H9 H14 H13 H12 H10 H11 C1 C2 C3 C4 C5 C AC H H H H CW = 38,293 kW AC = 8,677 kW H = 73,410 kW CW

Process Integration Analysis Introduction Objectives Process Integration Analysis Conclusions Acknowledgements PINCH ANALYSIS SUGGESTED DESIGNS DATA COLLECTION SIMULATION EXISTING PROCESS DATA COLLECTION RETROFIT ANALYSIS DATA COLLECTION Process Integration Analysis

Exchanger Data

Economic Data HE : HEC($) = K 1 + K 2 A K3 T < 200  C (CS) : HEC($) = 33, A 0.78 T > 200  C (SS) : HEC($) = 33, ,795 A 0.78 Utilities Cooling water: 9.23 $/kW y Cooling air: 8.31 $/kW y Fuel gas: 57.4 $/kW y 1996 data Nelson-Farrar Cost Index

Process Integration Analysis Introduction Objectives Process Integration Analysis Conclusions Acknowledgements PINCH ANALYSIS SUGGESTED DESIGNS DATA COLLECTION SIMULATION EXISTING PROCESS PINCH ANALYSIS RETROFIT ANALYSIS PINCH ANALYSIS Process Integration Analysis

 Tmin [C] 0.25E E E E E E E E E+08 Total Cost Capital Cost Operating Cost ($/y) Optimum  T MIN

Enthalpy [kW] T(  C) Q H,MIN = 55,553 kW Q C,MIN = 29,881 kW Composite Curves

Process Integration Analysis Introduction Objectives Process Integration Analysis Conclusions Acknowledgements PINCH ANALYSIS SUGGESTED DESIGNS DATA COLLECTION SIMULATION EXISTING PROCESS   RETROFIT ANALYSIS Process Integration Analysis  RETROFIT ANALYSIS

Network Pinch Method Pinching matches  bottleneck How to overcome pinching matches?

Network Pinch Method DIAGNOSIS STAGE New Modifications OPTIMISATION STAGE Energy - Capital Cost Trade-off Existing HEN Suggested Design

(8) 2 nd RESEQUENCE HE16, stream C1 (9) 1 st NEW HE HE34: H14 – C2 (10) 2 nd NEW HE HE35: H12 – C2 (11) 3 th NEW HE HE36: H11 - C1 (7) 1 st RESEQUENCE HE4, stream C1 (12) 1 st NEW HE HE34: H14 – C2 y (13) 2 nd NEW HE HE35: H12 – C2 (14) 3 th NEW HE HE36: H4 - C1 (3) 3 th REPIPING HE16: H10  H11 (4) 1 st NEW HE HE34: H13 - C1 (6) 3 th NEW HE HE36: H7 - C1 (1) 1 st REPIPING HE8: H7  H14 (2) 2 nd REPIPING HE8: C1  C2 (5) 2 nd NEW HE HE35: H5 - C2 EXISTING HEN

Process Integration Analysis Introduction Objectives Process Integration Analysis Conclusions Acknowledgements PINCH ANALYSIS SUGGESTED DESIGNS DATA COLLECTION SIMULATION EXISTING PROCESS SUGGESTED DESIGNS RETROFIT ANALYSIS SUGGESTED DESIGNS Process Integration Analysis

(7) 1 st RESEQUENCE HE4, stream C1 EXISTING HEN

OPTION I In need of further study Payback Time  1 months Savings = 114,190 $/y (9) 1 st NEW HE HE34: H14 – C2 (7) 1 st RESEQUENCE HE4, stream C1 EXISTING HEN

OPTION II Capital Investment = 133,983 $ Payback Time = 4 months Savings = 320,610 $/y OPTION I In need of further study Payback Time  1 months Savings = 114,190 $/y (9) 1 st NEW HE HE34: H14 – C2 (10) 2 nd NEW HE HE35: H12 – C2 (7) 1 st RESEQUENCE HE4, stream C1 EXISTING HEN

OPTION II Capital Investment = 133,983 $ Payback Time = 4 months Savings = 320,610 $/y OPTION III Capital Investment = 648,803 $ Payback Time = 10 months Savings = 495,440 $/y OPTION I In need of further study Payback Time  1 months Savings = 114,190 $/y (9) 1 st NEW HE HE34: H14 – C2 (10) 2 nd NEW HE HE35: H12 – C2 (11) 3 th NEW HE HE36: H11 - C1 (7) 1 st RESEQUENCE HE4, stream C1 EXISTING HEN

OPTION II Capital Investment = 133,983 $ Payback Time = 4 months Savings = 320,610 $/y OPTION III Capital Investment = 648,803 $ Payback Time = 10 months Savings = 495,440 $/y OPTION IV Capital Investment = 829,367 $ Payback Time = 11 months Savings = 586,190 $/y OPTION I In need of further study Payback Time  1 months Savings = 114,190 $/y (9) 1 st NEW HE HE34: H14 – C2 (10) 2 nd NEW HE HE35: H12 – C2 (11) 3 th NEW HE HE36: H11 - C1 (7) 1 st RESEQUENCE HE4, stream C1 EXISTING HEN

100, , , , , , , , , , , Payback Time (months) Utility Cost Saving ($/y) Option III Option II Option V Option I Option IV

112.8  C 92.4  C  C  C  C  C  C  C 90  C 70  C 40  C 50  C 210  C 90  C 20  C  C  C 220  C 348  C 110  C 350  C 370  C  C 63.2  C 144  C 315  C  C  C  C 63.6  C 69.1  C  C 60  C 150  C 76.8  C  C  C H1 H2 H3 H4 H5 H6 H7 H8 H9 H14 H13 H12 H10 H11 C1 C2 C3 C4 C5 C

OPTION IV - SUGGESTED DESIGN 1 Re-sequence + 3 New HE Utility savings Hot utility = 12+% Cold utility = 19+% Emissions reduction (9 MW) Capital Investment = 830,000 US$ Payback Time < 10 months

PINCH ANALYSIS SUGGESTED DESIGNS DATA COLLECTION SIMULATION EXISTING PROCESS RETROFIT ANALYSIS EXISTING PROCESS DATA COLLECTION PINCH ANALYSIS SIMULATION SUGGESTED DESIGNS RETROFIT ANALYSIS Network Pinch Method Diagnosis Stage Optimisation Stage Different Options (4) Suggested Topology 1 Re-sequencing. + 3 New HE Savings Hot utility = 12+% Cold utility = 19+% Emissions reduction (9 MW) Payback Time 10 months