Holistic Approach to Capturing and Sustaining Energy Savings · Holistic Approach to Capturing and...

©2006 Aspen Technology, Inc. All rights reserved

Holistic Approach to Capturing and Sustaining EnergySavings

December 7th, 2006

2©2006 Aspen Technology, Inc. All rights reserved

Outline

•What is energy management?

•Advanced Process Design

•Sustainability

•Holistic approach

•Summary


Energy Flow and Profitability

Supply Profile

Demand Profile


Energy Management Components

Supply SideSupply Side

(Utilities)(Utilities)

DesignDesign

OperationsOperations

Demand SideDemand Side

(Processes)(Processes)


Energy Management –Time Horizons





Strategic Planning

Tactical Planning

Scheduling

Operating Decisions

Control

Years

Months/Weeks

Days

Hours

Minutes

DesignDesign



Utilities system modeling

Total Site Pinch Analysis

Optimize utilities system design

Cogeneration Feasibility

GHG Planning

Energy/yield/purity/throughputtrade-off

Process/Column Pinch Analysis Catalyst Replacements Process re-sequencing &

optimization Establish energy targets

Energy Management Components



Operator Decision SupportSystem

Performance management Dynamic targeting & alerting Heat Exchanger Monitoring Advanced Control Real time Optimization

Fuel, Steam & Poweroptimization

Performance Management Utilities Contract Management Emissions management Reduce flaring & venting



DesignDesign



RawMaterials

DesiredProductsProcess?

The objective of process design is the creation of a process toconvert raw materials into desired products

What is Process Design?


Feed Heat Cool

Reactor

Process design starts with the Reactor



FEED RECYCLE

Cool

CoolCoolHeat

Heat

Heat

Heat

ReactorFEED

PRODUCT

BYPRODUCT

The reactor design dictatesthe separation and recycle problem



Cool

Cool

Heat

Heat

Heat

Reactor

FEED

FEED

PRODUCT

BYPRODUCT

The reactor and separator system dictate the heating and cooling dutiesof the streams, so the heat exchanger network can be developed

FEED



CW

CW

Steam

Steam

Steam

ReactorFEED

FEED

PRODUCT

BYPRODUCT

Those duties which cannot be satisfied by heat integrationdictate the need for .external utilities

Steam Mains

CoolingTower

FEED



Reactor

Separation Scheme

Heat ExchangerNetwork

Utility Selection

Base Case

Different possibilitiesfor heat recovery

Type, SequencePressure, Feed ConditioningSide Reboiler / Condenser

Steam, Hot OilFlue gas, Refrigerant

Type, Phase, CatalystPressure, Temperature

Once a base case design has been developed, this can then beimproved by considering Structural and Parametric Changes

Process Improvement


Engineer Modeling

Quantify real impact

Idea # 3 ......Idea # 2Idea # 1,

Traditional Approach to Process Improvement


SynthesisGenerate Ideas

ModelingEvaluate Ideas

Engineer

Quantify real impact

Set targetsIdentify critical designchanges

Key Ideas

AspenTech Advanced Process Design


Modeling

ModelingExistingProcess

ExistingProcess

ImprovedProcess

ImprovedProcess

Reduced Modeling EffortBetter Improvement Option

Impact on ProcessConfiguration

Why use Process Synthesis?

Value•5-30% energy savings with 1-2 years payback (energy and emissions reduction)•5-15% capacity increase with 10-30% less capital (plant debottlenecking)

Value•5-30% energy savings with 1-2 years payback (energy and emissions reduction)•5-15% capacity increase with 10-30% less capital (plant debottlenecking)


Design for Energy EfficiencySamsung General Chemicals, Daesan (Korea)

Site Profile

•Energy costs had risen

dramatically since plant start-up

(oil price $17 $29 $40 )

•By 2000, the annual energy bill for

the complex was over $60MM

•SGC began to study radical

revamp plans to significantly

reduce energy costs

Business Challenges

How AspenTech Helped•Joint project executed by Samsung General Chemicals / Samsung

Engineering / AspenTech.•Several SGC’s ideas were used, together with new ideas generated from

modelling and energy system optimization analysis.•Practical project ideas developed and costed.($9.1MM)•20%+ energy savings achieved. ($12MM/year)

•SGC operates a large aromaticscomplex in Daesan, Republic ofKorea

•Built in 1997•Capacity:

480,000 MTA Paraxylene240,000 MTA Benzene100,000 MTA Toluene

Complex-wide revamping for energy optimization

Aromatic Complex Revamping


Design for Energy EfficiencyZero Capital Opportunities

Site Profile

•Rigorous, predictive Aspen plus model

•Detailed analysis and specific

operational modifications of:

•Ethane-propane feed splitter

•Cold box- Demethaniser

•Ethylene splitter / fractionator

•Rigorous acceptance testing of all

modifications

Deliverables

Results•Changes were easily implemented and tested within a 4 month period.•Energy savings in excess of $500,000 / year with no capital

expenditure.•Many other potential improvements and debottlenecking opportunities

identified for future development.•Unit personnel gained more knowledge, which has helped improve

operation and optimization efforts

•Ethylene Plant•Capacity - 1 billion lb per annum•Ethane/propane feedstock

Aromatic Complex RevampingCrackingFurnaces

GasSweetening Quench

Diln Steam

Compression1-3

NaOH WashDrying

Cold Box

Chilldown

Companders

EthyleneReFridge

DeEthaniser

DePropaniser

Stabiliser

EthyleneSplitter

DeMethaniser

C3's

C5's

C4's

H2

Methane

Ethylene

Ethane r/c

EthaneFeed

PropaneReFridge

Steam System

Comp-4

AcetHydro

PropaneFeed

PyGas

Water

Framework•Pay-for-performance fee basis

•Zero capital expenditure


Design for Energy EfficiencyZero Capital Opportunities (cont.)

Demethanizer Operational Improvements–Cold Box refrigeration loads / profile shifted

•Make better use of higher level refrigeration and lower duty on colder

refrigeration levels

–Methane Circulation maximized

Hydrogen purity

Hydrogen intrusion into demethanizer

Recycles to methane refrigeration compressor (MRC)

Pressure required at PGC and Demethanizer

–Methane in Bottoms Reduced to 50 ppm, Side Reboiler Duty Reduced

& Pre-heater Flow Increased

•Properly balanced tray loading

•Maximized separation efficiency


Sustainability

A year later….

Most of the operational improvements had regressed to their

original state

Why?–Inadequate follow-up by process engineering to train operations

–“But we’ve always run it that way”mentality

–Staff turn-over

–Lack of management attention

–No on-line performance management system


Performance Management System


Energy Investment Plan &

Program Management

Energy Investment Plan &

Program Management

Energy Management AnalysisEnergy Management AnalysisAssess Current State of site energy managementAssess Current State of site energy managementMap improvement needs to AspenTech capabilitiesMap improvement needs to AspenTech capabilitiesPlan the Energy Management ProgramPlan the Energy Management Program

Holistic Approach

Supply SideSupply Side(Utilities)(Utilities)

Demand SideDemand Side(Processes)(Processes)

DesignDesign


Energy / yield / purity / throughputtrade-off

Process/Column Pinch Analysis Catalyst Replacements Process re-sequencing & optimization Establish energy targets

Operator Decision Support System Performance management Dynamic targeting & alerting Heat Exchanger Monitoring Advanced Control Real time Optimization

Utilities system modeling Total Site Pinch Analysis Optimize utilities system design Cogeneration Feasibility GHG Planning

Fuel, Steam & Power optimization

Performance Management

Utilities Contract Management

Emissions management

Reduce flaring & venting


Month 1 Month 2 Month 3 Month 4 Months 5 & 6 Months 7 to 9 10 to 12 13 to 18

Typical Sequence of Events

EnergyManagement

Analysis

Program Management

Engineering Design, Construction &CommissioningAdvanced Process

Design

Utilities ManagementUtilities Planning Utilities Operations

Energy

TargetsOperationalImprovements

CapEx Projects

Operational Improvements

Advanced Process Control / Real-time Optimization


Base-lining Targeting Continuous Improvement


SummaryV

alu

e

Time

=

Syn

erg

y+

Su

stai

nab

ility

Consulting report

No Knowledge transfer

Implement Point Solutions

Transfer Know-how & models

Investment Plan

Program management


Deliverables

SYNERGY –Design, Operation, Supply & Demand workingtogether towards the same goal

SUSTAINABILITY –Capture improvements, then “Sustain the Gains”

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