Truls Gundersen March 18.pdf

8/20/2019 Truls Gundersen March 18.pdf

1/30

NTNU

20.03.13 T. Gundersen Slide no. 1

What is Process Integration?

by

Truls Gundersen

Department of Energy and Process Engineering

Norwegian University of Science and Technology (NTNU)

Trondheim, Norway

Chalmers

University of

Technology


2/30

NTNU


Content of the Presentation

! Definitions and the birth of Process Integration

!

Process Integration (PI) as a Term ! Heat, Power, Chemical and Equipment Integration

!

Some early stage Developments, however …! Bodo Linnhoff: “A Historical Overview of early Developments”

! 3 Major and Generic Results from Pinch Analysis with

widespread Use in Process Integration

!

The Tool Box in PI ! Graphical Diagrams, Representations and Concept

!

Various Extensions of Pinch Analysis in PI

!

Applications, Objectives, Scope, etc.! Use of Optimization in Process Integration

!

PI and Global Warming / Emissions Reduction! From Energy Focus to Environmental Concern


3/30

NTNU


P R O C E S S I N T E G R A T I O N

IEA

OECD

The IEA Definition

of Process Integration

From an Expert Meeting

in Berlin, October 1993

"Systematic and General Methods for Designing

Integrated Production Systems, ranging from

Individual Processes to Total Sites, with specialemphasis on the Efficient Use of Energy and

reducing Environmental Effects"


4/30

NTNU


More Descriptions of Process Integration

!

An Alternative to the IEA Definition:

!

Process Integration is a Methodology for Analysis, Design andOptimization of Material and Energy related Production Systems

! What is unique in Process Integration (PI)? ! Pinch Analysis (PA) was developed in the 1970s/1980s based on

the Discovery of a Heat Recovery Pinch, and PA was the Birth of

PI as a Systems oriented Process Design Methodology

! PA/PI represented a Departure from Traditional Design Practice

! Improving Process Technologies (following the Learning Curve)

through Operating & Engineering Insight using Design based on

Case Studies was replaced by Systematic Design using Targets

!

The new Design Methods enabled Step Changes in Performance

! The real Value of Performance Targets ahead of Design: ! Removing the Uncertainty among Engineers whether a Process

Design could be further improved and by how much


5/30

NTNU


!

#!!

$!!

%!!

&!!

'!!!

'#!!

'$!!

'%!!

'&!!

' ( % ! )

% (

' ( * ! ) * (

' ( & ! ) & (

' ( ( ! ) ( (

# ! ! ! )

# ! ! $

# ! ! + )

# ! ! (

# ! ' !

) , - . / . 0 1

The use of Process Integration as a Term

Date: 7 March 2013 – Source: Science Direct, Journal papers only

Subjects: Chemical Engineering, Energy, Engineering

0 8121

714 651

1420

1666

2071


6/30

NTNU


The Title: What is Process Integration?

This Question can be decomposed into

What do we mean by a Process?

and

What do we mean by Integration?


7/30

NTNU


Energy

Material

Com Exp

Raw Material(s) Product(s)

Byproduct(s)

Thermal Energy

HP, MP, LPFlue Gas

AP, CW

Refrigerants

Thermal Energy

HP, MP, LP

Cooling

Mechanical

Energy

A Process can be regarded as a “Converter”


8/30

NTNU


What is the meaning of Integration?

!

Integration means combining Needs/Tasks of “opposite”

kinds so that Savings (or Synergies) can be obtained! Examples of such Integration in the Process Industries:

! Heat Integration

• Cooling & Condensation integrated with Heating & Evaporation

• Identify near-optimal Level of Heat Recovery

•

Design the corresponding Heat Exchanger Network! Power Integration

• Expansion integrated with Compression

• Same Shaft or combined in “Compander”

! Chemical Integration

•

Byproducts from one Plant used as Raw Materials in other Plants•

The Idea of materials integration is used in Industrial “Clusters”

! Equipment Integration

• Multiple Phenomena (Reaction, Separation, Heat Transfer) are

integrated in the same piece of Equipment" Process Intensification


9/30

NTNU


Heat

Integration

2000 4000 60000

300

250

200

150

100

50

T (°C)

H (kW)

Q H,min

QC,min

Pinch

Q Recovery

!T min

Pinch

180°

C2210° 160°

C1210°

50°

H2

220° 60°

H1

270°160°

160°

Ca

4

4

H

1

13

3

2

2

190° 177.6°

1000 kW

1000 kW 620 kW 880 kW

Cb

360 kW

440 kW

2200 kW

160°

180°

180°

80°

235.6°

mCp (kW/°C)

18.0

22.0

20.0

50.0

270ºC - - - - - - - 250ºC

230ºC - - - - - - - 210ºC

220ºC - - - - - - - 200ºC

180ºC - - - - - - - 160ºC

160ºC - - - - - - - 140ºC

70ºC - - - - - - - - 50ºC

H1

H2

CW

C1

C2

ST

720 kW

180 kW

720 kW

880 kW

440 kW

1980 kW

500 kW

200 kW

800 kW

1800 kW

+ 720

- 520

- 1200

2000 kW

400 kW

+ 180

+ 220

+ 400

60ºC - - - - - - - - 40ºC

360 kW

220 kW

!T min

= 20°C300

250

200

150

100

50

T' (°C)

Q (kW)

500 15000

QH,min

QC,min


10/30

NTNU


Simultaneous Heat and Power Integration?

!

Feng and Zhu (1997) introduced the Energy Level (!)

!

Energy Level is defined as Exergy/Energy: ! For Work and Electricity: ! = 1

! For Heat: ! = "C = 1 " T 0 / T

! For Steady-State Flow Systems: ! = # E / # H

! The Energy Level Concept is used to identify Losses inEnergy Quality (which is why Exergy is used)

!

Energy Level is evaluated at the Entrance and Exit of theProcess Units based on inlet and outlet Process Streams

!

Energy Level Composite Curves (ELCCs) are Energy

Level vs. Enthalpy Curves plotted in a Cumulative manner! Energy Level of Units will increase or decrease

! Synergies possible through Integration?

! Problem: High Energy Level caused by Temperature or Pressure?


11/30

NTNU


Anantharaman R., Abbas O.S., Gundersen T., “Energy Level Composite

Curves – A New Graphical Methodology for the Integration of Energy Intensive

Processes”, Applied Thermal Engineering , vol. 26, pp. 1378-1384, 2006.

0

0.1

0.2

0.3

0.4

0.5

0.6

0 50 100 150 200 250 300 350 400 450 500

Cummulative Enthalpy (MW)

E n e r g

y

L e v e l

Omega Increasing Units

Omega Decreasing Units

Raw Product Cooler

Raw Product Cooler,

Sec Reformer Product Cooler

Raw Product Cooler,

Sec Reformer Product Cooler,

Prereformer 1

Sec Reformer Product Cooler,

Prereformer 1

Sec Reformer Product Cooler

Steam Generator

Steam Generator, Burner, MeOH Recycle Compressor

Steam Generator, Burner, MeOH Recycle Compressor, Syn Gas Compressor

Steam Generator, MeOH Recycle Compressor, Syn Gas

Steam Generator, Syn Gas Compressor

Steam Generator, MeOH Reactor Feed Preheater

Steam Generator, MeOH Reactor

Steam Generator, MeOH Reactor Water Jacket

Steam Generator, MeOH Reactor Water Jacket, Prereformer 2

Steam Generator, Prereformer 2

Prereformer 2

Prereformer 2, Primar Reformer

Primary Reformer, Sec Reformer

Primary Reformer, Sec Reformer Shift Reactor

Primary Reformer

ELCCs for a Methanol Process


12/30

NTNU


Kaggerud K.H., Bolland O., Gundersen T., “Chemical and Process Integration:

Synergies in Co-Production of Power and Chemicals from Natural Gas with CO 2

Capture”, Applied Thermal Engineering , vol. 26, pp. 1345-1352, 2006.

Chemical Integration in an Industrial Cluster


13/30

NTNU


Equipment Integration – Methyl Acetate

Siirola J.J., “Industrial Applications of Chemical Process Synthesis”,

Advances in Chemical Engineering , vol. 23, pp. 1-62, 1996.

Eastman

Chemical

Company


14/30

NTNU

Process Synthesis

Process Integration

Heat Integration


Various Terms in Perspective

Energy

Conservation


15/30

NTNU


Some early stage

Developments

Energy

Equipment

Raw Materials

Environment G

r a s s r o o t

R e t r

of i t

B a t c h Bodo Linnhoff

used the Rubic Cube

to illustrate

Progress

From powerful results and insight based on the

Concept of a Heat Recovery Pinch through a

Development along several “axes” to reaching

the Level or Status of a Design Discipline !!


16/30

NTNU


3 Major Results from PA with widespread Use in PI

!

The Concept of Composite Curves (Cumulative Plots) ! Applicable whenever an “Amount” has a “Quality”! Heat & Temperature, Mass & Concentration (Chemical Potential),

Refinery Gases & H2 Purity (and Pressure), Money & Time, etc.

!

Targets for Best Performance ahead of Design

!

Decomposition of Systems into Surplus and Deficit Regions! PDM for Grassroot Design develops Separate Networks

! Process Modifications guided by the Plus/Minus Principle

! Appropriate Placement (or Integration) of Distillation Columns,

Evaporators, Heat Engines (Steam Turbines) and Heat Pumps

T

H

C

m

Heat

Pinch

Water

Pinch

QC,min

Q H,min

Water min


17/30

NTNU


Above

Pinch

Below

Pinch

Q H,min

QC,min

Q = 0

Process

Cascade

Q Reboiler

QCondenser

Distillation

Column

Heat

Pump

Q HP,out

Q HP,in

W HP

Steam

Turbine

QST,in

QST,out

W ST

“Correct” Integration and Appropriate Placement

Simple Rule: “Connect Sources with Sinks” But: T Source > T Sink


18/30

NTNU


Diagrams, Representations and Concepts in PI

!

Graphical Diagrams

!

Composite Curves! Grand Composite Curve

! Energy Target Plot

! Area/Energy Plot

! Driving Force Plot

!

Column Grand Composite Curve

! Exergy Composite Curves

! Exergy Grand Composite Curve

! Column Grand Composite Curve

! Total Site Source & Sink Curves

!

More?

!

Representations & Concepts

!

Process & Utility Pinch! Feasibility Table

! Problem Table

! Heat Cascade

! Grid Diagram

!

Penalty Heat Flow Diagram

! Bipartite Graph

! Heat Load Loops

! Heat Load Paths

! Rubic Cube and the “Onion”

!

More?

Important Tools for Analysis, Design and Optimization

as well as for Learning and Communication


19/30

NTNU


Expansions in Process Integration

based on Pinch Analysis

and using Analogies

! Applications Areas

!

Objectives

! Scope

! Type of Plants

!

Type of Projects

! Thermodynamics


20/30

NTNU


! Application Areas

# From Heat Pinch for Heat Recoveryand CHP in Thermal Energy Systems

# to Mass Pinch for Mass Transfer /Mass Exchange Systems

#

to Water Pinch for WastewaterMinimization and Distributed

Effluent Treatment Systems

#

to Hydrogen Pinch for HydrogenManagement in Oil Refineries

#

to Oxygen Pinch for Wastewater

Bio-Treatment Plants# to Carbon Pinch to satisfy Energy

Requirements while meeting CO2 Emission Limits in the Energy Sector

Expansionsof PA & PI


21/30

NTNU



! Objectives

#

from Energy Cost

# to Equipment Cost

#

to Total Annualized Cost

# and also Operability, including$

Flexibility

$ Controllability

$ Switchability% Start-up & Shut-down

% New Operating Conditions

#

and finally Environment, including

$ Emissions Reduction

$ Waste Minimization


22/30

NTNU



! Scope

#

from Heat Exchanger Networks# to Separation Systems, especially

$ Distillation and Evaporation (heat driven)

# to Reactor Systems

#

to Heat & Power, including$

Steam & Gas Turbines and Heat Pumps

# to Utility Systems, including

$ Steam Systems, Furnaces, Refrigeration Cycles

# to Entire Processes

# to Total Sites

# to Regions


23/30

NTNU



! Plants

#

from Continuous# to Batch and Semi-Batch

! Projects

# from New Design

#

to Retrofit

# to Debottlenecking

! Thermodynamics

# from Simple 1st Law Considerations

#

to Various 2nd Law Applications$ Exergy in Distillation and Refrigeration


24/30

NTNU


Process Integration Methodologies

Hierarchical

Analysis

Heuristic

Methods

Knowledge

Based Systems

Optimization

Methods

Thermodynamic

Methods

Pinch Analysis

Exergy Analysis

Stochastic Methods

Mathematical Programming

Rules of ThumbExpert Systems qualitative

quantitative

interactiveautomatic


25/30

NTNU


Limitations in Pinch Analysis & the PDM

! Rigor sometimes replaced by Heuristic Rules!

The (N – 1) Rule for minimum Number of Units!

The “Bath” formula for minimum total Heat Transfer Area

!

The Composite Curves have their Limitations! Cannot handle Forbidden Matches between Streams

! Simple Rules for Appropriate Placement do not work when

Distillation Columns are included in the Composite Curves !

The Pinch Design Method is Sequential in Nature ! Targeting " Design " Optimization (Evolution)

! One Match at a time, one Loop at a time, one Path at a time, etc. ! " Unable to properly handle Multiple Trade-offs

!

Pinch Decomposition guides Correct Integration, but ! In Network Design, less Costly and less Complex Designs can

be found by actually ignoring strict Pinch Decomposition

! Time consuming but normally results in “good” Designs


26/30

NTNU

2000 4000 60000

250

200

150

100

50

T (°C)

H(kW)

CW

HP


Why not use Optimization?

MILP

LP

NLP

Energy

Units

Area/TAC

Software: MAGNETS

Transshipment Models (LP & MILP)

Clever Stream Superstructure (NLP)

MINLP

Minimum Area

=> Counter-Current or

“Vertical” Heat Transfer

Area Considerations using

a “vertical” MILP Model?

Targeting

Design

Evolution

Gundersen T., Grossmann I.E., “Improved Optimization

Strategies for Automated Heat Exchanger Networks

through Physical Insights”, Comput. chem. Engng., vol.

14, no. 9, pp. 925-944, 1990.

CMU UMIST


27/30

NTNU


UMIST Comments after Sabbatical

Promoting Mathematical Programming

was quite challenging in those Days !


28/30

NTNU


The Sequential Framework – SeqHENS

Anantharaman R ., Gundersen T., “The Sequential Framework for Heat Exchanger

Network Synthesis – Network Generation and Optimization”, PRES’2007, Ischia

Island, Chemical Engineering Transactions, vol. 12, pp. 19-24, 2007

Compromise between Pinch Design and MINLP Methods

Surprisingly few Iterations thanks to excessive use of Insight

!

Heat Transfer Area: Loops 1 & 2

!

# of Heat Exchangers: Loop 3

!

Energy Consumption: Loop 4


29/30

NTNU


Process Integration and Global Warming

!

The IEA: 3 main Measures to reduce CO2 Emissions!

Energy Efficiency (short term, even profitable?)! Carbon Capture & Storage (medium term, expensive!)

! Renewable Energy Forms (long term, expensive?)

!

Public Discussion in the US (2012)! Energy Efficiency is the 5th Energy Form

!

Following Oil, Gas, Coal and Nuclear

!

An obvious Observation ! “The cleanest Energy is the one that is not used”

!

A Shift of Focus in Process Integration

!

From Energy Focus in the 1970s and 1980s (Availabilityand Cost) to Environmental Concern in the 1990s and later

!

Global Warming – A new Opportunity for PI? ! Energy Efficiency is a Core Activity in Process Integration


30/30

NTNU


Pinch Analysis developed by an “Accident”?

Bodo Linnhoff, PhD Thesis, University of Leeds, April 1979:

“Thermodynamic Analysis in the Design of Process Networks”

Abstract: “This thesis discusses the use of thermodynamic Second

Law analysis in the context of chemical process design”

2nd

Law of Thermodynamics for Open/Flowing Systems:

dS cv

dt =

!Q j

T j + !mi ! si " !m ! se + !# cv

e

$i

$ j

$

Entropy (S ) is the twin brother/sister of Exergy ( Ex)

dExcv

dt = 1!

T 0

T j

"

# $

%

& ' ( !Q j ! !W cv ! p0 (

dV cv

dt

" # $

% & ' + !mi (e f ,i ! !m (e f ,e ! ! Exd

e

)i

) j

)

Documents

Truls Gundersen March 18.pdf