Energy efficiencies in refineries_UOP.pdf

7/24/2019 Energy efficiencies in refineries_UOP.pdf

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Opportunities for energy efficiencies inRefineries & Petrochemical PlantsOpportunities for energy efficiencies inRefineries & Petrochemical Plants

November 2009November 2009

2008 UOP LLC. All rights reserved. UOP 5033B-01


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2020

Waxman- Markey: 20% reduction in GHG by 2020

0

CO2eq

milliontes

Business as usual

2012

5800

2005Baseline

4600

6400

Proposed Levels

3%

9% by 2030

2050

20% 83%

2030

23% 32%

53%

%

RenewablesofT

otalEnergyDem

and


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Background

The current state of the economy, along with the need forbetter environmental performance are driving moreefficient operations and improved process technologies

We must find the synergy betweenenergy efficiency and profitability

Making basic energy efficiency improvements is a relativelylow-cost way refiners and petrochemical producers canreduce operating costs, and GHG emissions

Few refiners today are taking a holistic, multi-facetedperspective that looks at process conditions, processdesign changes and technology to explore


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Energy & CO2 in a Refinery

700,000 million cubic feet of naturalgas/year

8% of crude is consumed as energy

Energy costs 50% to 60% of total variableoperating costs (excluding feedstocks)

$80 to $100 million/year on energy & 1.2to 1.5 million metric tons/year of CO2

CO2 emissions increase with heavierfeedstock, cleaner fuels, conversion andcomplexity

17CDU/VDU

% ofEnergy

ConsumedRefining Unit

5Offsite

15Utilities

4Coker

15Alkylation andHydrotreating

10Hydrocracking

14Reformer

20Fluid CatalyticCracking (FCC) Unit


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Our Goal is NOT Energy Minimization

Minimum energy is not always optimum profit

Energy is an enabler

More energy, can be used to realize greatercapacity, better yield, and better products

The overall process impact must be included inthe economic evaluation


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Finding the Right Solution

Need a holistic, multi-faceted approach to explore the synergybetween energy efficiency and profitability

Optimized energy use,control, and processconditions to unlock

hidden energyopportunities

LowCost Solutions

Minimum processdesign changes to

seek synergy ofenergy saving andthroughput/yield

enhancement

ModerateCost Solutions

Advancedtechnology to

maximize processefficiency in reaction,separation, heat and

power recovery

HigherCost Solutions


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Opportunities

32,000 to 44,000metric tons/year$8 to

10M/year1 to 2 %

Optimize H2 recovery

Maximize LPG recoveryH2 and Fuel Gas

Management

Total

Optimization and controls for onsitesteam and power production/supplyand demand optimization

Employ new process technology,design, equipment and catalysttechnology

Increase heat recovery within andacross process units.

Improve online monitoring, controland optimization throughmultivariable, predictive control andoptimization applications

Actions

24,000 to 36,000metric tons/year

$3M to6M/year

2 to 3%Utilities

Optimization


$5M to10M/year

3 to 7%AdvancedProcess

Technology

164,000 to320,000 tons/yr

$23M to39M/year

12 to 25%


$4M to8M/year

4 to 9%Improved heat

recovery


$3 to 5M/year2 to 4%Improved

operation andcontrol

CO2Reduction

ProfitIncrease

EnergyImprovement

Area of Savings

Basis: for a 100,000 BPSD refinery; natural gas cost @ $6/MMbtu


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Where Energy Savings Come From

UseCarbonCredits

GetEnergy

Cheaper

Improve ResourceAllocation

Balance Supply& Demand

Boiler/Turbine

Performance

Online Control& Optimization

Improve Monitoring& OperationOperate More

Efficiently

GHG Capture& Storage

RenewableEnergy Source

Improve Heat IntegrationRecover

More Heat

Utilize NewProcess

Technology

Advanced ProcessTechnology, Equipment

& Catalysts

Reduce Waste/Leaks

ManagingH2/Fuel

SystemsEfficiently

Minimize H2 to FuelBetterManage H2 Manage H2 Partial

Pressure

Maximize Recover ofValuable Components

Minimize FuelGas Flare

Better ManageFuel

Gas System

UseEnergyMore

EfficientlyIn Process

ReduceEmissions

ReduceEnergy

Costs andEmissions


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Operate More Efficiently



EfficientlyUse

EnergyMore


ReduceEmissions

ReduceEnergy

Costs andEmissions

UseCarbonCredits

GetEnergy

Cheaper



Boiler/Turbine

Performance




More Heat

Utilize NewProcess

Technology


& Catalysts

Reduce Waste/Leaks

ManagingH2/Fuel

SystemsEfficiently


Pressure



Better ManageFuel

Gas System


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How to capture hidden operational opportunities:

Optimize complex fractionation/separation systems

Pump-arounds; Feed temperature; Operating pressure

Minimize product give-away

Maximize throughput/lift/desirable products

Optimize complex interactions

Interactions between heaters, heat recovery systemsand processes

Interactions between process energy demand and utilityenergy supply sides



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Optimize energy/processes under changing conditions

Variations in feeds, products, production rate Fouling in heat exchangers, condensers and heaters

Energy Dashboard

Determine targets for key processand energy variables

Monitor actual vs. predicted energyconsumption

Instrumentation for measurement

The key is to optimizecomplex systems and interactions


Capture hidden operational opportunities:


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Advanced Control and Optimization

Multi-variable control and optimization tools

Maximize production, improve yields, minimize energy

Include energy costs as part of overalleconomic operating objectives

Energy related solutions include:

Furnace Pass Balancing and Excess Air

Distillation Quality and Pressure Control

Reactor Conversion Control

Preheat Maximization

Process know-how workingtogether with powerful tools



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Advanced Controls Case Study

YNCC, South Korea

400 ktes/yr Ethylene Plant

Naphtha feedstock to 7 furnaces Constraints in furnaces, refrigeration compressors and fractionators

Implemented 17 MPC controllers and an optimizer with non-linearcracking model

Operating Results

Increased naphtha feed rate by 3.0%

Reduced energy consumption by 3.25% -reduced steam consumption in fractionators;furnace excess O2

Project payback ofless than5 months


1. Normal Operation w/o APC

2. W/ APC3. Maximum Load

(W/ APC + OPT)

Operating Results


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CO2 Reduction of 24-48 kMt/yrfrom a typical

100,000 bbl/day refinery

Whats It Worth ?

2~4% improved energy efficiency

$3 to 5M/year


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Heat recovery within and across process units

Integration of process energy with utility systems

Energy savings combined with increased throughput Determine process bottlenecks

Transfer expensive bottlenecks to cheap ones

Optimize operating conditions simultaneouslypressures / specs / pump-arounds / rundowns

Practical considerations for any changes

Safety, operability, reliability

Recover More Heat


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Recover More Heat

A = Effluent Frac Feed Exchanger 1B = Effluent Frac Feed Exchanger 2C = CFE 1 (Effluent Feed Exchanger)D = CFE 2 (Effluent Feed Exchanger)E = Diesel P/A Heavy Naphtha Exchanger

PRT

Add powerrecovery turbine

Medium energy benefit

at medium costAdd 4-Hx (A-D) to beforeRx & Frac charge heaters

Energy & Throughput benefit

Low Cost

A

C

C

B

D

D

B

A


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PRT

Install combinedconvection section for two

charge heaters

Large energy benefitat high cost

Optimize the ratioof flow through the

split (non-symmetric)raw feed trains

No cost energy benefit

Recover More Heat


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PRT

Charge heatersare less full

More feed can be addedto the unit

Change catalyst forbetter cold flow property

Change Rx internal forbetter vapor/liquid

distribution

More product

Recover More Heat

Charge Frac/separatorinternals

Improved throughputButpoorer diesel

cold-flow properties

~100 MMBtu/h saved

and 15% increase inthroughput


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$4 to 8M/year

CO2 Reduction of 48-108 kMt/yrfrom a typical

100,000 bbl/day refinery

Recover More Heat

Whats It Worth ?



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Utilize NewProcess

Technology


UseEnergyMore


ReduceEmissions Advanced Process

Technology, Equipment& Catalysts

ReduceEnergy

Costs and

Emissions

UseCarbonCredits

GetEnergy

Cheaper



Boiler/TurbinePerformance



Efficiently



ManagingH2/Fuel

Systems

Efficiently


Pressure



Better ManageFuel

Gas System


More HeatReduce Waste/Leaks


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B

A

ABC

C

Take advantage of new technology, equipmentand catalysts

High selectivity/activity catalyst

High efficiency reactor internals

High capacity fractionator internals

Enhanced heat exchangers

Modern power recovery turbines

Novel process design

UOP 5027I-18

Utilize New Process Technology


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SpongeAbsorber

MainColumn

Stripper DEC4

PrimaryAbsorber

NaphthaSplitters

HCN

LightNaphtha

MiddleNaphtha

Aromatics RichNaphtha

Heavy Gasoline

LCO

CSO

LPG

Unstabilized Gasoline

LCO PA

DEC4 BTMSRecycle

To Fuel GasSystem

Can this beimproved?

Feed

Wet GasCompressors



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SpongeAbsorber

MainColumn

Stripper DEC4

PrimaryAbsorber

NaphthaSplitter

HCN

LCO

CSO

LPG

Unstabilized Gasoline

LCO PA

LNRecycle

To Fuel GasSystem

Feed

Wet GasCompressors

HG

ARN

MN

LN

Modifications:

LN for primary absorber Dividing wall columns

Benefit:

9 MkCal/h or 3% energy savingfor 70 kBPD FCC



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Thermal Efficiency In DividingWall Column

A

ABC

B

C

Colum

nTray

Top

BottomComponent B mole fraction

Col 1 Col 2

Remixing occurs

A

ABC

B

C

Vertical wall separates columnsections

Eliminates thermal inefficiency 3 products using a single column

Typically 25-40 % savings in capitaland energy costs

Dividing Wall Column



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Whats It Worth ?


CO2 Reduction of 36-84 kMt/yrfrom a typical 100,000

bbl/day refinery


$5 to 10M/year


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ManagingH2/Fuel

Systems

Efficiently


Pressure



Better ManageFuel

Gas System

RecoverMore Heat

Utilize NewProcess

Technology


& Catalysts

Reduce Waste/Leaks

UseEnergyMore


ReduceEmissions

UseCarbonCredits

GetEnergy

Cheaper








Efficiently

Improve Heat Integration

ReduceEnergy

Costs and

Emissions


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Better Manage H2 & Fuel Gas System

Advantages of Improved H2 Management:

H2 Plant is one of the largest emitters of CO2

Can improve refinery margin through processperformance improvement

Avoid capital expense on new H2 plant

Alleviate H2 constraints


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H2 Network AnalysisMatching purities of producers & consumers

Cascades

Purge Rates

H2 purificationRecover H2 now going to fuel

Revamp existing purifiers

Add new purification capacity

Optimize processMaximize H2 yield in reformers

Set / maintain H2 partial pressure targets


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Monitor C3/C4 % in refinery fuel gas

Recover valuable components in refinery fuel gas

Use excess fuel gas for cogeneration

Have a mitigation plan for

fuel gas long scenarios


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Whats It Worth ?

1~2% improvement in energy efficiencyfrom the refinery

CO2 Reduction of 32-44 kMt/yrfrom a typical 100,000

bbl/day refinery


$8 to 10M/year

Significant process benefit


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GetEnergy

Cheaper




UseCarbonCredits GHG Capture

& Storage


RecoverMore Heat

Utilize NewProcess

Technology


& Catalysts

Reduce Waste/Leaks

UseEnergyMore


ReduceEmissions



Efficiently

Improve Heat Integration

ManagingH2/Fuel

Systems

Efficiently


Pressure



Better ManageFuel

Gas System

ReduceEnergy

Costs and

Emissions


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Supply/Demand Optimization

Realtime supply/demand balance

Meet demand forecastaccounting for price, emissions,availability, make vs. buy

Boiler Optimization

Accept steam loads andallocate according toefficiency and constraints

Master Pressure Control

Advanced predictive control

Stabilize header pressures

AdvancedCombustion Control

Tight Fuel/air ratio

Control excess O2

Power Users

Electricity

HPS - 500 psi

MPS - 150 psi

LPS - 50 psi

TG-1TC-1

Boiler-1 Boiler-2

150#Users

500#Users

Power Supply Grid

50#Users

Purchased

Steam

TC-2 TG-2 TG-3

50#Vent

Air Air

Plant AirUsers

CONDENSATE

LDV-1

LDV-2

LDV-3

Power Users

Electricity

HPS - 500 psi

MPS - 150 psi

LPS - 50 psi

TG-1TC-1

Boiler-1 Boiler-2

150#Users150#Users

500#Users500#Users

Power Supply Grid

50#Users

Purchased

Steam

TC-2 TG-2 TG-3

50#Vent

Air Air

Plant AirUsers

CONDENSATE

LDV-1

LDV-2

LDV-3

Get Energy Cheaper

Energy Mix

Optimize choice of fuel

Optimize dual drivemotors

Turbine Optimization

Accept electrical loadsand balance according to

efficiency and price


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Whats It Worth ?

2~3% improvement in energy efficiencyfrom the refinery

CO2 Reduction of24-36 kMt/yr

from a typical 100,000bbl/day refinery

Get Energy Cheaper

$3 to 6M/year


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Energy Solutions Summary

Basis: for a 100,000 BPSD refinery; natural gas cost @ $6/MMbtu

32,000 to 44,000metric tons/year$8 to

10M/year1 to 2 %

Optimize H2 recovery

Maximize LPG recoveryH2 and Fuel Gas

Management

Total

Optimization and controls for onsitesteam and power production/supplyand demand optimization

Employ new process technology,design, equipment and catalyst

technology

Increase heat recovery within andacross process units.

Improve online monitoring, controland optimization through

multivariable, predictive control andoptimization applications

Actions


$3M to6M/year

2 to 3%Utilities

Optimization


$5M to10M/year

3 to 7%AdvancedProcess

Technology

164,000 to320,000 tons/yr

$23M to39M/year

12 to 25%


$4M to8M/year

4 to 9%Improved heat

recovery

24,000 to 48,000

metric tons/year

$3 to 5M/year2 to 4%Improved

operation and

control

CO2Reduction

ProfitIncrease

EnergyImprovement

Area of Savings


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Implement

Operation &MaintenanceSolutions

Implement

Operation &MaintenanceSolutions

SustainBenefits

ImplementEquipment& ControlProjects

ImplementEquipment& ControlProjects

ROI

Prepare FEEDfor Equipment &Control Projects

Prepare FEEDfor Equipment &Control Projects

Execution

Energy OpportunityAssessment

(Benchmarking &Prelim analysis)

Energy OpportunityAssessment

(Benchmarking &Prelim analysis)

Detailed Study

& AnalyzeOpportunities

Detailed Study

& AnalyzeOpportunities

StartReview

OpportunitiesReview

Opportunities

ReviewOpportunitiesReviewOpportunities

Deploy

On-LineMonitoring

Deploy

On-LineMonitoring

PrelimOnline

Monitoring

PrelimOnline

Monitoring

ImplementQuickHits

ImplementQuickHits


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Conclusions

There is NO single approach

Reduce operating costs and CO2 emissions while increasingprofitability

Improved throughput and yields are possible The demands from the process must be tightly linked to supply

from the utilities plant.

Identification of good energy projects requires combined skills in

operation, process design, modeling and energy optimization Sustaining the benefits requires monitoring and

optimization tools, on-line and closed loop control

Technology is the key

Energy savings of12-25% are possible


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Thank You

Documents

Energy efficiencies in refineries_UOP.pdf