reconciling mass and energy balances in an ethylene complex
DESCRIPTION
Emerson's Patrick Truesdale presents steps to improve energy efficiency in ethylene production processes.TRANSCRIPT
Reconciling Mass and Energy Reconciling Mass and Energy Balances in an Ethylene ComplexBalances in an Ethylene ComplexReconciling Mass and Energy Reconciling Mass and Energy Balances in an Ethylene ComplexBalances in an Ethylene Complex
Patrick TruesdaleSenior ConsultantIndustry Solution GroupEmerson Process Management
November 11, 2009Nashville, TN
© Emerson Process Management 11-Nov-2009, Slide 2
Presentation ObjectivesPresentation ObjectivesPresentation ObjectivesPresentation Objectives
Background and Business Challenge Business Opportunities How to Achieve? Case Examples Summary
© Emerson Process Management 11-Nov-2009, Slide 3
IntroductionIntroductionIntroductionIntroduction Accurate measurements are an essential part
of a refinery or petrochemical complex Measurement technology has dramatically
improved in past 25 years Environmental and governmental regulations
have increased necessitating accurate measurements
Changing demographics Benefits can be significant!
© Emerson Process Management 11-Nov-2009, Slide 4
SteamCracker
CondensateSplitter
ACUVDU
FCC
Reformer
Hydrotreating
BTX
DistillateProcessing
GasolineProcessing
Benzene
Toluene
Xylene
Jet, Kero, Diesel
Fuel Oil
Gasoline
Propylene
Ethylene
Propylene
Butadiene
Benzene
Toluene
Feed Stock
Condensate
Crude
Reformate
Aro
mat
icN
aph
tha
Gas
Oil
Pyr
olys
is F
O
FC
C G
as Hyd
roge
n
C6
+ fr
act
ion
C4
raff
ina
te
Jet
Fu
el
Die
sel F
uel
Ethylene Plants: Ethylene Plants: Configuration and ComplexityConfiguration and ComplexityEthylene Plants: Ethylene Plants: Configuration and ComplexityConfiguration and Complexity
Ref: T. Ren, University of Utrecht and BASF 2000
© Emerson Process Management 11-Nov-2009, Slide 5
Statistic World NA LA EU/FSU MEA APEthylene Capacity (MM tons/yr) 126.7 35.4 5.1 33.5 19.3 33.4Breakdown (%wt)
Naphtha 55 20 80 75 10 75Ethane/propane/Butane 30 70 20 5 85 5
Other 15 10 0 20 5 20Propylene Capacity (MM tons/yr)Total Process Energy (EJ) 3 0.6 0.2 0.8 0.5 0.9Total CO2 Emission (MM tons/yr) 193 45 7 55 26 60
43% from Cracker/57% from refinery
Ethylene Plants:Ethylene Plants:Estimated Capacities – 1 Jan. 2009Estimated Capacities – 1 Jan. 2009Ethylene Plants:Ethylene Plants:Estimated Capacities – 1 Jan. 2009Estimated Capacities – 1 Jan. 2009
Ref: OGJ 30 July 2009
© Emerson Process Management 11-Nov-2009, Slide 6
Ethylene Plants: Ethylene Plants: Global Distribution and AgeGlobal Distribution and AgeEthylene Plants: Ethylene Plants: Global Distribution and AgeGlobal Distribution and Age
PredominantlyGreenfield
PredominantlyBrownfield
In 1980’s Plants were typically ca 300kta
Now Mega Crackers > 1,000kta
© Emerson Process Management 11-Nov-2009, Slide 7
Hydrocarbon/Measurement TimelineHydrocarbon/Measurement TimelineHydrocarbon/Measurement TimelineHydrocarbon/Measurement Timeline
1600 1700 1800 1900 1940 1980 2000 Present
347 ADChinaWells
1594 ADBakuWells
Petroleum
1662Boyles Law
1730'sPitot,
BernoulliTechnology
< 4,000 BC“Fountain of Pitch”
1790Woltman
1800'sVenturi
PD MeterCoriolis
1846Gesner(Kero)
1898ASTM
1854Pa. Rock Oil
Co.
1872Barrel = 42
gals.
Economics
Whale Oil$0.40/gal
Kero$0.47/gal
1918AGA1919API
1902NPRA
1940Daniel
Orifice Fitting Co,
1960 1990
1970EP A 2002SO X
1977M MIC ori oli sM ete r
1 9 5 0+ Ele c tr o n ic Er a
2003So nar Met er1963U lt raso nicM ete r 2005Sm ar t Met er
Crude Price Profile (Cushing WTI Spot FOB)
10
30
50
70
90
110
130
150
US
$/B
bl
1859Drake Well
1970EPA
2002SOX
1977MMI
CoriolisMeter
1950+ Electronic Era
2003Sonar Meter
1963Ultrasonic
Meter
2005Smart Meter
19361st Ethylene
Plant1669
Becher
© Emerson Process Management 11-Nov-2009, Slide 8
Challenges to achieve benefitsChallenges to achieve benefitsChallenges to achieve benefitsChallenges to achieve benefits
1. Measurement systems for Mass are relatively new for old Plants
2. Belief that errors are mostly due to fuel gas/oil production/consumption over/under statement (ie. Little need to coordinate energy usage with losses)
3. Prices have escalated rapidly in past few years; currently many plants are spending significant capital to met new specs, increase capacity, regulatory compliance, process cheaper feed stocks. Staff is stretched.
4. Business function and organization requires addressing NOT just software tools; but the new operator and engineer in plant.
© Emerson Process Management 11-Nov-2009, Slide 9
Typical Plant DemographicsTypical Plant DemographicsTypical Plant DemographicsTypical Plant DemographicsOperations Engineering Maintenance
Small decline dueto automation
Downsized by 70 - 90% Downsized by 5% per year for past 10 years.
0-20 21-34 35-44 45-54 55-65 65+Age
Typical Plant w/ 3,308 workers • Operators now responsible for optimization efforts• 75+% experienced operators slated to retire by 2015• Skilled labor pool falling
© Emerson Process Management 11-Nov-2009, Slide 10
Meet the New Engineers and Operators!Meet the New Engineers and Operators!Meet the New Engineers and Operators!Meet the New Engineers and Operators!
We may dress funny but we’re computer geeks!
We may dress funny but we’re computer geeks!
We may dress funny but we’re computer geeks!
We may dress funny but we’re computer geeks!
© Emerson Process Management 11-Nov-2009, Slide 11
Key Performance IndexesKey Performance IndexesKey Performance IndexesKey Performance Indexes
Asset Utilization Plant Reliability Operating Efficiency Margin Energy Efficiency Loss Opportunities Environmental Safety
© Emerson Process Management 11-Nov-2009, Slide 12
Where are losses? Why Important?Where are losses? Why Important?Where are losses? Why Important?Where are losses? Why Important?
Open Inventory + Receipts – Shipments – Closing Inventory = Gain/Loss
Gain/Loss = Accountable + Unaccountable
Leaks
Theft
FlareCoke
Fuel Produced
Fuel Consume
d
© Emerson Process Management 11-Nov-2009, Slide 13
Energy EfficiencyEnergy EfficiencyEnergy EfficiencyEnergy Efficiency
© Emerson Process Management 11-Nov-2009, Slide 14
Step 1: Step 1: Define Process BoundariesDefine Process BoundariesStep 1: Step 1: Define Process BoundariesDefine Process Boundaries
C2 Hydrogenation
Cold Box C2 S
plitter
Dep
rop
ani
zer
C3 Hydrogenation
C3 S
plitter
Deb
utan
izer
Deeth
aniz
er
Cracked Gas Compressor
Quench Tower
Cracking Furnaces
Hydrogen 1%-9%
Methane 6%-28% (fuel)
Ethylene 23%-76%
Ethane 3%-20% (recycle)
Propylene 3%-16%
Propane 2%-10%
C4s 2%-9%
Gasoline <1%-35%
Steam & Waste Heat
Steam
SteamFeeds (60%)
Ethane (C2)Propane (C3)Butane (C4)Naphtha (C5 – C12)Gas Oil (C10 – C15)
Fuel Gas
Dem
ethan
izer
Drying and Chilling
Ethylene and Propylene Refrigeration Systems
Steam (40%)
Quench Water Circuit
Oil / Tar Fractionator
Fuel Oil
Tar
800-900 °C1.5 bar
350 °C1.5 bar
30 °C1.5 bar
10 °C1.5 bar -100 °C
32 bar
20 °C5 bar
50 °C2 bar
-10 °C30 bar
10 °C10 bar
-10 °C30 bar
75 °C30 bar
70 °C8 bar
90 °C5 bar
45°C5 bar
45°C16 bar
35°C16 bar
-20 °C20 bar
-30 °C20 bar
-6 °C20 bar
80 °C1.5 bar
FiredHeater
Distillation
CryogenicDistillation
HydrogenationReactor
TurboCompressor
© Emerson Process Management 11-Nov-2009, Slide 15
Shore Ship
Consumers
Raw Material Production & Supply Ethylene Complex
Load Port
Logistics
Unload Port
Ship Shore ShoreShip TransportationLoss
Load Port
Transportation LossShore
Unload Port
Ship
BOL
BOL$ “The Cash Register”
Step 2:Step 2:Identify Custody Transfer Boundaries? Identify Custody Transfer Boundaries? Step 2:Step 2:Identify Custody Transfer Boundaries? Identify Custody Transfer Boundaries?
© Emerson Process Management 11-Nov-2009, Slide 16
Step 3: Step 3: Design Mass and Energy BalancesDesign Mass and Energy BalancesStep 3: Step 3: Design Mass and Energy BalancesDesign Mass and Energy Balances
ReceiptsReceipts ShipmentsShipments
IntercompanyIntercompany
InventoriesInventories
Tank-to-tank transfers
Tank-to-tank transfers
Unit-to-tank
transfers
Unit-to-tank
transfers
Process Nodes
Process Nodes
Tank-to-unit transfers
Tank-to-unit transfers
LossesLosses Consumption
Consumption
© Emerson Process Management 11-Nov-2009, Slide 17
Step 4:Step 4:Survey Measurement SystemsSurvey Measurement SystemsStep 4:Step 4:Survey Measurement SystemsSurvey Measurement Systems
With poor instrumentation and procedures:= 1.5 - 2.5% Mass losses
With average instrumentation and procedures:= 0.7 – 1.5% Mass losses
With good instrumentation and procedures:
= < 0.5% Mass losses
Pacesetter = <0.2%Pacesetter = <0.2% Pacesetter look at Solomon KPI; Others such Shell Global Services, Juran, etc.
© Emerson Process Management 11-Nov-2009, Slide 18
Select Technology RequiredSelect Technology RequiredSelect Technology RequiredSelect Technology Required
Pressure Drop Accuracy
LowMaintenance
SlurryFlows
ViscosityIndependent
Flow meterType
Non-ConductiveFluids
Non-Intrusive
Turbine
PositiveDisplacement
Coriolis
Magmeter
DifferentialPressure
Vortex
Good Marginal Poor
Ultrasonic
© Emerson Process Management 11-Nov-2009, Slide 19
Coriolis Measurement CapabilitiesCoriolis Measurement CapabilitiesCoriolis Measurement CapabilitiesCoriolis Measurement Capabilities
Direct MASS flow measurement Rangeability: (100:1 non custody), (20:1 custody)
Accuracy (@20:1 turndown)
− Mass Flow Rate: ±0.10 %− Volume Flow Rate: ±0.13%
Unaffected by most fluid variations− P,T,density,viscosity, conductivity− Velocity profile independent
Bi-Directional Multi-variable outputs available
− Qm, Qv, T, Density, % Solids, Viscosity
© Emerson Process Management 11-Nov-2009, Slide 20
Tank Gauge Measurement CapabilitiesTank Gauge Measurement CapabilitiesTank Gauge Measurement CapabilitiesTank Gauge Measurement Capabilities
1 API ± 3/16" (4 mm)2 PTB, Germany3 NMi, Netherlands4 OIML, International5 TankRadar
© Emerson Process Management 11-Nov-2009, Slide 21
21
Flow meters or ATG’s ?Flow meters or ATG’s ?Flow meters or ATG’s ?Flow meters or ATG’s ?
Influence of batch size:
– At large transfer volumes ATG’s have potential to have better performance. Systematic error on a meter will have a large influence.
– At small transfer volumes meters have potential to have better performance. Resolution may not be sufficient on an ATG.
© Emerson Process Management 11-Nov-2009, Slide 22
Do errors always get even out? Do errors always get even out? Think again!Think again!Do errors always get even out? Do errors always get even out? Think again!Think again!
NO: Statistical sum of several measurement errors equals:
Square Root of the sum of Square of the errors
When adding several errors, sum can not be zero!
© Emerson Process Management 11-Nov-2009, Slide 23
Step 6:Step 6:Develop Mass & Energy Balance ModelsDevelop Mass & Energy Balance ModelsStep 6:Step 6:Develop Mass & Energy Balance ModelsDevelop Mass & Energy Balance Models
Validation, Detection and Correction: Gross and Bias Errors Reconciles for Random Errors
– Mass and Volume balancing • Flows, inventories, material transfers
– Component balancing (Simple and Multi-phase)• Flows, inventories
– Energy balancing• Enthalpy, power, heat exchanger balance, steam
– Simultaneous Solution of all equations
© Emerson Process Management 11-Nov-2009, Slide 24
Example Heat Balance EnvelopeExample Heat Balance EnvelopeExample Heat Balance EnvelopeExample Heat Balance Envelope
100 Kg9.242 MJ91423.7 J/Kg
100 Kg1.068 MJ10683.6 J/Kg
100 Kg4.217 MJ42170 J/Kg
100 Kg12.291 MJ122.9 KJ/Kg
100 Kg3.871 MJ38706 J/Kg
100 Kg11.944 MJ11944.6 J/Kg
Flow Measurement Tolerance Reconciled Value MT1 10 kg 1.5 kg 10.3 kg
T1 HT1 42174 J/kg 843.5 J/kg 42237 J/kg
T2 MT2 11 kg 5.5 kg 10.3 kg
HT2 31631 J/kg 3163.1 J/kg 30724 J/kg
MS1 12 kg 1 kg 11.64 kg S1
HS1 21087 J/kg 1054.4 J/kg 21203 J/kg
MS2 11 kg 1.55 kg 11.64 kg S2
HS2 31631 J/kg 1581.5 J/kg 31356 J/kg
© Emerson Process Management 11-Nov-2009, Slide 25
Example Heat Balance EnvelopeExample Heat Balance EnvelopeExample Heat Balance EnvelopeExample Heat Balance Envelope
100 Kg9.242 MJ91423.7 J/Kg
100 Kg1.068 MJ10683.6 J/Kg
100 Kg4.217 MJ42170 J/Kg
100 Kg12.291 MJ122.9 KJ/Kg
100 Kg3.871 MJ38706 J/Kg
100 Kg11.944 MJ11944.6 J/Kg
Flow Measurement Tolerance Reconciled Value MT1 10 kg 1.5 kg 10.3 kg
T1 HT1 42174 J/kg 843.5 J/kg 42237 J/kg
T2 MT2 11 kg 5.5 kg 10.3 kg
HT2 31631 J/kg 3163.1 J/kg 30724 J/kg
MS1 12 kg 1 kg 11.64 kg S1
HS1 21087 J/kg 1054.4 J/kg 21203 J/kg
MS2 11 kg 1.55 kg 11.64 kg S2
HS2 31631 J/kg 1581.5 J/kg 31356 J/kg
© Emerson Process Management 11-Nov-2009, Slide 26
Step 5:Step 5:Define Business ProcessDefine Business ProcessStep 5:Step 5:Define Business ProcessDefine Business Process
Period EndCutoff Data
Period EndCutoff Data
Gross Error Detectionand Diagnostics
Gross Error Detectionand Diagnostics
TrialBalancing
TrialBalancing
Resolution orReconciliation
Resolution orReconciliation CheckingChecking
ModificationsAdjustments
ModificationsAdjustments
ComplexConfiguration
Models
ComplexConfiguration
Models
MeasurementsMovements
Lab DataMeter Tickets
Surveyor Documents Tank Inventories
Utilities
MeasurementsMovements
Lab DataMeter Tickets
Surveyor Documents Tank Inventories
Utilities
ResultsGeneration
ResultsGeneration
ManualInput
Automatic DataCollection
Reconciled Balances, Yield, Loss and Inventory
Reporting
Reconciled Balances, Yield, Loss and Inventory
Reporting
Production Management
Data Base
Production Management
Data Base
Integrate withOther Systems
(SCM, SAP, LP, etc)
Integrate withOther Systems
(SCM, SAP, LP, etc)
© Emerson Process Management 11-Nov-2009, Slide 27
Gross Margin versus Weight Loss
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
Month
Wt
% W
eig
ht
Lo
ss
0
50
100
150
200
250
Gro
ss
Ma
rgin
in k
$
Weight Loss Gross Margin
Step 7:Step 7:Identify KPI ReportingIdentify KPI ReportingStep 7:Step 7:Identify KPI ReportingIdentify KPI Reporting
© Emerson Process Management 11-Nov-2009, Slide 28
KPI DashboardKPI DashboardKPI DashboardKPI Dashboard
© Emerson Process Management 11-Nov-2009, Slide 29
What went wrong??
What went right??
Step 8:Step 8:Implement Continuous ImprovementImplement Continuous ImprovementStep 8:Step 8:Implement Continuous ImprovementImplement Continuous ImprovementWhere did it happen?• Models• Process• Data Quality
Time (Weeks)
• Capacity
• Utilization
• Production rate
• Quality
• Energy
• Yield
• Margin
• Reliability
• Environmental
Before(Monthly)
Plan/Schedule
1 2 3 4 5 6 7 8 9 10 11 12 13 14
ActualOperation
After(Daily)
© Emerson Process Management 11-Nov-2009, Slide 30
Get Benefits:Get Benefits:Operational Excellence ImpactOperational Excellence ImpactGet Benefits:Get Benefits:Operational Excellence ImpactOperational Excellence Impact
Up to 7.9% OperationalImprovement by Impacting…
+3% +2.4%
-1.3% -1% -0.2%
© Emerson Process Management 11-Nov-2009, Slide 31
Measurement Losses:Measurement Losses:What is it worth?What is it worth?Measurement Losses:Measurement Losses:What is it worth?What is it worth?
93%
1150$/t
500$/t
Assume 0.2% Loss Reduction
© Emerson Process Management 11-Nov-2009, Slide 32
Measurement Losses:Measurement Losses:What is it worth?What is it worth?Measurement Losses:Measurement Losses:What is it worth?What is it worth?
Assume 0.2% Loss Reduction
•Product •Capacity •Price •Margin •Utilization factor •Amount•Ethylene •900 kMT/yr •1 150 $/t •500 $/t •93% •47 774 $/hr•Propylene •450 kMT/yr •1 150 $/t •500 $/t •93% •23 887 $/hr
•$71 661•0.2% •$143/hr•1 hr
•1 yr •$1 255 500
© Emerson Process Management 11-Nov-2009, Slide 33
Range
• Custody transfer (receipt and shipments)
• Fuel and H2 consumption (understated, not real losses)
• Flare, in effluent, evaporation, stack loss, vents and leaks, coke
0.35 to 0.55
0.85 to 1.05
0.45 to 0.65
TOTAL 1.65 to 2.25
Case 1: Case 1: Losses Analysis (%Mass)Losses Analysis (%Mass)Case 1: Case 1: Losses Analysis (%Mass)Losses Analysis (%Mass)
Estimate
0.45
0.95
0.55
1.95
© Emerson Process Management 11-Nov-2009, Slide 34
Case 1: Case 1: Benefit CalculationBenefit CalculationCase 1: Case 1: Benefit CalculationBenefit Calculation Estimate loss = 1.95%
– Custody Transfer Loss = 0.45%
– Flare, Coke, Other Loss = 0.55%
– Apparent (understated fuel/H2 consumption) = 0.95% Improvement
– Achievable Goal = 0.4%• Delta = (0.45%+0.55%-0.4% = 0.6%)
• 0.6% x 12MM T/yr x 210US$/T = $15,120,000/yr
Supply chain optimization– 0.25 $/T x 12MM T/yr = $3,000,000/yr
© Emerson Process Management 11-Nov-2009, Slide 35
Case 2: Case 2: Measurement Errors vs Economic LossesMeasurement Errors vs Economic LossesCase 2: Case 2: Measurement Errors vs Economic LossesMeasurement Errors vs Economic Losses
Operating Region
Control Variable
Ob
ject
ive
Fu
nct
ion
(e.
g.
Pro
fit)
Deviations are often corrected with high-cost sub-optimum
correction!
Potential lost profit from inaccurate measurements.
© Emerson Process Management 11-Nov-2009, Slide 36
Trading BenefitsTrading BenefitsTrading BenefitsTrading Benefits
A Gulf Coast refiner switched a cargo of crude with justone-and-a-half hours of supply left in inventory.
Without very close coordination between trading and operations,the $8 million profit opportunity would have been lost.
Hydrocarbon Processing
© Emerson Process Management 11-Nov-2009, Slide 37
Trading ExampleTrading ExampleTrading ExampleTrading Example
Trader
Gulf Coast Complex
Okay, if you can agree with the shipper to deliver 8 hours earlier, then we will have a four hour safety margin and the trade is agreed.
Hold on while we check:: - Current inventory - Maintenance Plan - Agreed Receipts and Shipmentsand rerun the schedule to check the impact on stocks and cash flow.
Delivery 8 hours earlier is agreed. We make $3,000,000 and we extend our credit line by 3 days. GREAT, is there anything I can do to help with a backup strategy?
We have an excellent opportunity to purchase a cargo of feed stock. Can we take it?
© Emerson Process Management 11-Nov-2009, Slide 38
Key TakeawaysKey TakeawaysKey TakeawaysKey Takeaways Ethylene plants have large incentives to reduce losses and
optimize energy usage. These two KPI are interrelated. With the sharp increase in feedstock prices and accessibility, the
industry has a compelling need for improving the timeliness and accuracy of production data.
Specifications and governmental regulations continue to tighten - accurate measurements are essential to mitigate compliance
Since late 1950 there has been and continues to be significant technological improvement in measurement systems
Smart Instruments and Wireless technology opens additional benefits for the future!
Improved accuracy of Production Data (Mass and Energy Balance Reconciliation) impacts many KPI’s . The solution approach, therefore, “is Greenis Green” (provides significant benefits).
© Emerson Process Management 11-Nov-2009, Slide 39
Wrap-upWrap-upWrap-upWrap-up
Questions? Comments?
Where to get more information?– White Papers
– Presentations
– Specific requirements?
– Contact: Patrick Truesdale ([email protected])
© Emerson Process Management 11-Nov-2009, Slide 40
Thank You