IETC Energy Manager's Workshop 1
1
The Industrial Energy The Industrial Energy
ManagerManager’’s Essential s Essential
Tool KitTool Kit
Energy ManagersEnergy Managers’’ WorkshopWorkshop39th Industrial Energy Technology Conference
New Orleans, LA, 19 June 2017
J D Kumana, MS ChE
Kumana & Associates, Houston, Tx
[email protected] (281) 437-5906
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Outline
� Background
� Technical Approach
� Portfolio of Tools and Techniques
� Case Study (Lagniappe)
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Industrial Processes – Inputs and Outputs
UTILITYSYSTEM
MFGPROCESS
WASTETREATMENTELEC
FUEL
ELEC?
RAW MATGHG
PRODUCTS
EFFLUENTDISCHARGE
ENERGY
CONTROLLABLE PARAMETERS
• RAW MAT YIELDS• REACTION KINETICS• UNIT OPERATIONS
• RECYCLE POINTS & RATES
• ENERGY CONSUMPTION
PROCESS MODS
• Heat Recovery • Power reduction• Optimize CHP
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Impact on Profits
GHG EMISSIONS
ENERGY COST
WASTE TREATMENT
THROUGHPUT OR CAPACITY
YIELD + KINETICS
ENERGY EFF (SUPPLY)
ENERGY EFF (USAGE)
OPTIMUM RECYCLE
UNIT OPERATIONS
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Ideally, we should consider both Process and Energy on Integrated Basis
� PROCESS MODIFICATIONS
� Potentially Huge Impact, but Higher Cap Cost + some Potential Risk
� ENERGY EFFICIENCY OPTIMIZATION
� Smaller Impact, but Lower Cap Costs & Almost Zero Risk
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NOT
MY
JOB
STEAM
POWERELECUTILITY
PARADIGM: Utilities available instantaneously at ZERO costRESULT: Waste Energy in both Process & CHP System
R1
R2 SEP
F1
F2
P1
P2
Y
Process Engineer’s Viewpoint
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B1 B2
DA
HRSG
C
Y
GT
condensate
BD
NOTMY JOB
PARADIGM: Must supply demand at ANY CostRESULT: High Flexibility, Low Efficiency
Utility Engineer’s Viewpoint
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Economics
EnergyUtilitiesProcess
• Energy• Emissions• Capacity
Integrated Optimization Viewpoint
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Outline
� Background
� Technical Approach
� Portfolio of Tools and Techniques
� Case Study (bonus)
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Process Energy Optimization (PEO)
Using Energy Analysis (fuel +
power) to identify and exploit
profitable opportunities for
process efficiency improvement
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PEO Integrates Process and Utilities
Energy Supply,Conversion, &
Distribution Systems
Waste Collection,Reduction, Recovery,
& Discharge
Raw Mat’ls:Feed Stocks,
Coal, etc.
FinishedChemical Products
Chemical Plant“Processing”
Steps (see PFD)
A “high level” view of the Process and Utility Systems
PEO looks at the Process and Utility Systems as a single Unified System
“We had never suspected that using energy differently can improve the process”.
David Broad, Site Mgr. BASF
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PEO uses Financial and Technical Modelsto directly link Engineering w/ Economics
An Engineering Model A Financial Model
THE SYSTEM(EQUIPMENT)
THE PROCESS
¨TEMPERATURES, ETC.¨PRACTICES of PEOPLE¨ TECHNOLOGY
THE BUSINESS UNIT
Power Plant Cost
Center
RAWMATERIALS
ENERGY
SCRAP
DEPRECIATION,TAXES, INSURANCE $
LABOR $
OTHER $
ENERGY $
SCRAP $
NETSALES $
RAW MAT’LEXPENSE $
REWORK
OTHER
LABOR
GROSSSALES $
PROFIT $
G&A andSELLINGEXP$
RETURNS &DISCOUNTS $
REWORK $
• WASTEWATER TREATMENT $,• AIR EMISSIONS $• SOLID WASTEDISPOSAL $
ENVIRONMENTALEMISSIONS
FINISHEDPRODUCT
Optimization Links-- “X% What ifs”: What is the annual K$/yr saving from a 1% or 10% annual improvement in product output, yields, quality, maintenance
effectiveness, operator productivity and energy performance?
Optimization links ?
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PEO Methodology
� Documentation - process & econ. models
� Correct product/waste & utility pricing
� Identify major $ impacts on Bottom Line, using sensitivity analysis (What If?)
� Focus on Critical Cost Issues (CCIs)
� 3-phase approach
• Level 1 – rules of thumb, ball park economics
• Level 2 – prelim calculations, conceptual design
• Level 3 – detailed calcs, vendor quotes
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PEO – Key Features
� Integrated holistic analysis
� 3-phase approach (increasing levels of effort and accuracy)
� Collaborative Effort � Consultant plays
“coach/facilitator” role at Level 1; Team member at Level 2
� Immediate Results
� Implementation Road Map
� Thorough documentation
� Plant Ownership and Accountability (KPIs)
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Outline
� Background
� Technical Approach
� Portfolio of Tools and Techniques
� Case Study (bonus)
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Technical Tool Kit
� “COST FLOW” DIAGRAMS for CCIs
� STRUCTURED BRAIN-STORMING
� PFDs and HMB SIMULATION MODELS
� OPERATIONAL IMPROVEMENTS
� EQUIPMENT UPGRADES
� PROCESS INTEGRATION (Pinch Analysis)
• PROCESS MODS – higher capacity & yields, less waste
• OPTIMIZED HEAT RECOVERY
• OPTIMIZED CHP STRUCTURE
� PERFORMANCE MONITORING
Level 1
Levels 2 & 3
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Example of 1-line Cost Flow Diagram
Utilities: Major Chemical Plant site, Texas
#1 #2 #3 #4 #5 #6
#7
Steam ElectricityNatural
GasCoolingWater
WastewaterTreatment
Incineration
CompressedAir
TreatedWater
Utilities
$6,647 k/yr55.9%150k MWh$44.4/MWh
$3,487k/yr29.3%590k MBtu$5.91/MBtu
$420k/yr3.5%10,244k kgal$0.041/kgal
$1k/yr0.0%1k SPU$1.20/SPU
$74k/yr0.6%3k klb$23.06/klb
$42k/yr0.4%58k kgal$0.724/kgal
$37k/yr0.3%214k kcf$0.174/kcf
#8$60k/yr0.5%314k kcf$0.174/kcf
$11,900k/yearEC TEX PE-1 Utilities
#9
$1,131 k/yr9.5%205k KESV$5.51/KESV
Nitrogen
CRITICAL COST ISSUES
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Structured Brainstorming w/ Stakeholders
Site Participants Include:
� Site & Mfg. Unit Mgmt.
� Raw Matls./Interm. Supplier
� Process Tech. Experts
� Plant Shift Operations Rep.
� Maintenance Specialist
� Finance/Business Rep.
Totals: 6-10 Plant, plus 5-7 Consultant team
Involves Key People on an
‘AS NEEDED’ basis: Only
One Week per Mfg. Dept.
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Summary of Level 1 study
Quickly Present and Implement SolutionsUser Friendly Reports
Jump Starts Program, Instant CredibilityCreates Immediate $$ Results
Identifies Most Valuable SolutionsUses Financial & Technical Tools
Saves Time, Maximizes ResultsFocuses on Critical Cost Issues
Doable Solutions, Commit to ImplementInvolves Your Key People
Lowers Unit Cost of Finished ProductIntegrates Process and Energy
BenefitsFeatures
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Technical Tool Kit
� “COST FLOW” DIAGRAMS for CCIs
� STRUCTURED BRAIN-STORMING
� PFDs and HMB SIMULATION MODELS
� OPERATIONAL IMPROVEMENTS
� EQUIPMENT UPGRADES
� PROCESS INTEGRATION (Pinch Analysis)
• PROCESS MODS – higher capacity & yields, less waste
• OPTIMIZED HEAT RECOVERY
• OPTIMIZED CHP STRUCTURE
� PERFORMANCE MONITORING
Level 1
Levels 2 & 3
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Heat and Material Balance Simulation Models (Process + Utilities)
� Essential to get full understanding of how the Raw Materials and Energy are used
� Helps to pin-point areas of opportunity
� Suggests potential process improvements
� Essential design basis for Level 2 Energy Optimization study (process heat recovery as well as CHP system)
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Example PFD: Bio-process plant
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Example HMB model – biotech plant
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CHP System Simulation Model
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Marginal steam prices - discontinuous
1
1.5
2
2.5
3
3.5
4
4.5
0 25 50 75 100 125 150
Klb/h STEAM GENERATED
Incre
men
tal
Ste
am
Co
st,
$/K
lb
Target Steam savings
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Technical Tool Kit
� “COST FLOW” DIAGRAMS for CCIs
� STRUCTURED BRAIN-STORMING
� PFDs and HMB SIMULATION MODELS
� OPERATIONAL IMPROVEMENTS
� EQUIPMENT UPGRADES
� PROCESS INTEGRATION (Pinch Analysis)
• PROCESS MODS – higher capacity & yields, less waste
• OPTIMIZED HEAT RECOVERY
• OPTIMIZED CHP STRUCTURE
� PERFORMANCE MONITORING
Level 1
Levels 2 & 3
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Operational Improvements
� Following industry Best Practices
� Reducing Process variability
� Flowsheet Improvements via simple process piping/control modifications
� Optimum equipment load allocation policies
� Performance Monitoring & Targeting
� Process Controls (eg. CHP optimizer, MVC)
Energy Cost savings can be achieved at little or no capital costthrough:
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� Minimize running spares
� Avoid keeping equipment on hot standby
� Maintain Steam traps, insulation
� Steam/Air leak detection & repair program
� Cooling water treatment
� Boiler & Furnace O2 controls
� Burner management
� Flue gas stack damper control
� Minimize CW and process fouling
� Optimize HX cleaning schedules/techniques
Low-cost Best Practices
Motherhood and Apple Pie
MoreAdvancedmethods
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Benefits of Reducing Process Variability
� Energy savings
� Capacity debottlenecking (throughput)
� Improved product quality
� Improved yield
� Reduced wastes
� Increased profitability
REF. G. Buckbee, “Closing the Gap between Engineers and Management”, Chem Eng Prog, May 2010
PV = Process Variable (eg. prod. moisture %)SP = set pointMV = Manipulated Variable (eg. steam flow)
(Steam flow rate)
(Product moisture content)
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Flowsheet Improvements
• Minimize non-isothermal mixing
• Minimize non-isoconcentration mixing
• Minimize range of recycle loops
• Avoid needless heating / cooling / pumping
• Add Degrees of Freedom via piping/control modifications (e.g. bypasses, manifolds)
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Examples of Simple Piping mods
PROC 1 PROC 2STORAGE
CW
STM
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Load Management Concepts
� Minimize number of machines being operated in parallel
� Reduce the rate at which individual machines are being run, through minimizing recycle flows
� Operate equipment at near its maximum efficiency point, to the extent possible
� Assign maximum duty to the most efficient equipment (in a parallel set), and use the least efficient equipment as the “swing” machine
� Optimize sparing philosophy (eg. N+1 vs N+2)
� Add Degrees of Freedom as necessary
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Technical Tool Kit
� “COST FLOW” DIAGRAMS for CCIs
� STRUCTURED BRAIN-STORMING
� PFDs and HMB SIMULATION MODELS
� OPERATIONAL IMPROVEMENTS
� EQUIPMENT UPGRADES
� PROCESS INTEGRATION (Pinch Analysis)
• PROCESS MODS – higher capacity & yields, less waste
• OPTIMIZED HEAT RECOVERY
• OPTIMIZED CHP STRUCTURE
� PERFORMANCE MONITORING
Level 1
Levels 2 & 3
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Equipment Efficiency Upgrades
� Pumps
� Compressors
� Motors
� Heat Exchangers
� Fired heaters (furnaces)
� Boilers (fired and unfired)
� Steam & Gas Turbines
� Refrigeration cycles
Electronic spreadsheet templates are most convenient
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Retrofit selected motors with VSDs
903 MWH/yr
= $24.4 K/yr
ROI = 17.8 %
CONFIDENTIAL
Generally best when
• HP > 500• Load < 70%
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Pump Networks with and without VFDs
Capacity that results in ENERGY LOSSES (CV + Recirc.)
Load Management (pumps
on or off as required)
+ One pump running on VSD
(always ON)
Parallel +
Single VSDTime
Pump (n-1)
startup
n pumps ON
Pump n startup*
Flow Rate(Single or Parallel)
Head(Series)
1
2
n
All pumps on-lineat all times
Flow Rate(Single or Parallel)
Head(Series)
Time
“On-line”Capacity
Process Requirement
Intermediate scenario of Load Mgmt, where un-needed pumps are turned off, is not shown
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HX modification strategy
Goal = Move operating point towards Target Zone
Target operating zone
Fouling zone
Velocity (and ∆∆∆∆P) too high
REF. Screenshot, ExpressPlus® s/w from IHS-ESDU (2006)
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Shell-side Helical Baffles
BETTER TEMPPROFILE AND
FLOW PATTERN
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Furnace/Boiler Air Preheating
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Arbitrage: shifting duty between Utilities
New steam heaters can provide an additional degree of freedom to shift duty from high-cost hot oil to LP stm.
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Technical Tool Kit
� “COST FLOW” DIAGRAMS for CCIs
� STRUCTURED BRAIN-STORMING
� PFDs and HMB SIMULATION MODELS
� OPERATIONAL IMPROVEMENTS
� EQUIPMENT UPGRADES
� PROCESS INTEGRATION (Pinch Analysis)
• OPTIMIZED HEAT RECOVERY
• OPTIMIZED CHP STRUCTURE
• PROCESS MODS – higher capacity & yields, less waste
� PERFORMANCE MONITORING
Level 1
Levels 2 & 3
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How can we reduce Process Heat use?
� Avoid needless consumption (eg. more efficient equipment and operation)
� Recover higher-grade ‘waste heat’as much as possible (HEN)
MedLow Hi
Reusableheat
CWRfg
PROCESS
TEMPERATURE
Not Reusable
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Pinch Analysis: Composite Curves
Qcold
QhotT
em
p
Heat Load
Qhot & Qcold are the
energy targets
PinchUsed for Energy
Targeting
Used for Energy
Targeting
• Composite Curves represent the process heating and cooling duty profiles• Energy Targets are an excellent Benchmarking tool
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T
CoolingWater
Steam
Process HeatTransfer
DO NOT
• use Steam below Pinch
• use CW above Pinch
• transfer heat from process
streams above Pinch to
process streams below
Pinch
The Pinch Principle
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Grand Composite Curve - GCC
T
H
REFRIGERATION
COOLING WATER
LP STEAM
HP STEAM
Used for utilities
selection
Used for utilities
selection
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Finding the Global Optimum ∆∆∆∆Tmin
Goal is to identify Near-Optimum ∆Tm range
Near-Optimal range
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Grid Diagram identifies Pinch + XP ht tr
H1
H2 C
Pinch
176°
158° 158°
C2140° 140°
C1H140°
∆Tmin = 18°
XP ht tr is in this HX
212°
248° 86°
104°
356°
266°
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Driving Force Plot – HX placement in HEN
Bad Match
Good match
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Heat Recovery in Contractor’s design
Styrene Plant – new design, Japan (1)
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Heat Recovery in optimized Pinch design
Styrene Plant – new design, Japan (2)
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Save both Capital Cost and Energy
Styrene Plant – new design, Japan (3)
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100% conversion of Q ���� W
T
HeatEngine W
Q - W
QA - (Q - W)
A + W
HeatEngine W
Q
B - QQ - W
No improvement in system ηηηη
T
Heat
EngineW
Q - W
B + (Q - W)
QA
A + Q
Appropriate Placement - Cogeneration
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Optimum Utilities: Total Site Analysis
Curves are composites of the RESIDUAL heating and cooling duty segments from the GCCs of individual process units
Net processcooling demand= available heat
Net processheatingdemand
T
wHP
Req. Q
Enthalpy, MMBtu/hCW
BFW
LP stm
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Typical On-line CHP s/w Architecture
Hydrogen Fuel Steam Water ElectricityUtility Systems
External Utilities
Contracts
Emissions
Regulations
ProcessIndustrial
Site
Real-Time Optimizer finds the best way to operate all utilities subject to
contractual, environmental and operational constraints
Optimum
Utilities
Operations
Report
Measurements
Optimum
Set Points
Key
Performance
Indicators
Monitoring
and
Accounting
Reports
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Typical Savings = 4-5% vs Std practice
5,30 %
1,19%
-
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
10.00
19-1
2
26-1
2
2-1
9-1
16-1
23-1
30-1
6-2
13-2
20-2
27-2
6-3
Day
Savin
gs / T
ota
l E
nerg
y C
osts
(%
)
Ahorros Anuales
> 2 MM €/year
> 4%
Y axis = Deviation from Optimum = Remaining Savings Opportunity
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Workflow integrating Pinch Design method
� First structural optimization, using Pinch Analysis
� Then parametric optimization, using simulation models
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Magnitude of Savings = f (Payback)
Savings vs Payback
0
20
40
60
80
100
120
0 2 4 6 8 10 12
Simple Payback, yr
% o
f M
ax P
ote
nti
al
Low
High
If you set unrealistic ROI requirements, you will FAIL
Here
or Here?
NOT
possible
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Why use Pinch Analysis?
� Systematic procedure can find best flowsheet structure, even (in fact especially) for very complex plants
� Quicker + cheaper than traditional approach
� Rigorous energy targets; we know when to quit
� Saves energy and capital without sacrificing safety, operating flexibility, or reliability
� For new plant design, there is an optimum time to do it; but Mgmt needs to be made aware.
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Technical Tool Kit
� “COST FLOW” DIAGRAMS for CCIs
� STRUCTURED BRAIN-STORMING
� PFDs and HMB SIMULATION MODELS
� OPERATIONAL IMPROVEMENTS
� EQUIPMENT UPGRADES
� PROCESS INTEGRATION (Pinch Analysis)
• OPTIMIZED HEAT RECOVERY
• OPTIMIZED CHP STRUCTURE
• PROCESS MODS – higher capacity & yields, less waste
� PERFORMANCE MONITORING
Level 1
Levels 2 & 3
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Performance Metrics - KPIs and EPIs
INDEX TYPEINDEX TYPE
Corp KPICorp KPI
Plant EPIsPlant EPIs
� Product
� Process
� Equipment
APPLICATIONSAPPLICATIONS
� Org efficiency trend
� External Benchmarking
� Cost Accounting
� Economic dispatch
� Planning
� Performance trend monitoring
� Operations troubleshooting
� Design Improvement
� Process control
� Equipment troubleshooting
� Targeted maintenance
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Multi-tier structure – drilldown capability
Company
Bus Line 2
Sales & Mktg
Bus Line 3 Bus Line 4Bus Line 1
Corp SupportGen admin
Plant DPlant A Plant B Plant C
Process 2 Process 3 Process 4 Process 5Process 1 Utilities
Fractionator Compressor Fired HeatersReactors
Plant E
HX Pumps
KPI s
EPI s
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Necessary Features of Good KPIs
�� Directional ConsistencyDirectional Consistency: When we do something good (e.g. make more profit), the KPI should get better
�� Magnitude ConsistencyMagnitude Consistency: The magnitude of change in the Index should closely match the change in profit, or efficiency, or whatever it is we are measuring.
All KPIs must meet these 2 tests
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90 MBDoe saved in 6 yr; 50% target over 10 yr
0%
20%
40%
60%
80%
100%
120%
0 1 2 3 4 5 6 7 8 9 10
Program year
Corp
Ene
rgy E
ffic
iency I
ndex
Actual
Potential
Forecast
Projected
Energystudies
Operation
Implement-ation
REF. J D Kumana, “Corporate Energy Management Programs: A Case Study”, Chemical News (Nov 2010)
Major International O&G Co, 15 plants
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Benefits of Systematic PEO Approach
Time
Sa
vin
gs
($
)
With PEO
NPV = 2X W/O PEO
NPV = X
PEO Creates More and Better
Solutions.
>>> Twice as much
implemented in half the
time!
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The End
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Case Study – generic BioTech plant
� High-value biomass product
� Fermentation + evaporation + drying
� Design based on scale-up of lab process
� 8000 hours per yr operation
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Simplified PFD
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Base Case Utility Consumption & Costs
What would YOU do to improve process efficiency & economics ?
(includes Dryer steam duty)
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Level 1 PEO idea: Btm Cycle Cogen
• Operate Boiler at max design pr (600 psig)
• Add new superheating section (to 700 F)
• Add new Back Pressure Stm Turbexhausting at 175 psig
PRELIM RESULTGood economicsWarrants more study
STBOILER
KW
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Level 2 PEO study: Energy Targets
QH target = 15.2 MMBtu/h, vs 24 MMBtu/h actual use
EVAP OH VAPEVAP DUTY
DRYERVAC JET EXHAUST
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Grand Composite Curve ���� partial MVR
CW
175# steam
MVR Vac jet exhaust
Evap duty
Evap OH vapor
Dryer duty
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Revised CCs with right-sized MVR
Vac jet exh Dryer duty
Evaporation duty
MVR disch vapor
Residual EvapOH vapor
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PFD for Optimum Process Configuration
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Optimized Utility Costs & Savings
• Minor changes � Major opex savings (energy + CO2 + WWT)• New cream separator + recycle improves yield• New fermenter cooling design saved 50% of Rfg (not described)• 60% smaller cogeneration project � capital savings• Negligible technical risk; Zero commercial risk• Straight-forward methodology (minimal trial & error)