Process Perf Opt Intro 2011

8/3/2019 Process Perf Opt Intro 2011

http://slidepdf.com/reader/full/process-perf-opt-intro-2011 1/13

Department of Biochemical and Chemical Engineering

Process D namics and O erations Grou DYN

DN

Y

D

DN

NY

Y



What is Process Operations About?

What do chemical engineers do?• Invent new products

• nven new processes o pro uce o or new pro uc s

• Design new plants (from basic to detail engineering)•

• Manage (large) construction projects

Much of these activities are nowada s based on

predictive models, simulation and optimization But nothing works in reality as planned!

Someone has to bridge the gap between design andreality and make plants meet specs and be profitable

• Process operations is a scientifically well-founded area ofchemical engineering that is indispensable for industry

PPO IntroWS 2011/12 D

NY

D

DN

NY

Y2



The Essence of Process Operations:How to Handle Uncertainty

Uncertainty is a pervasive aspect of (bio)chemicalprocess design and operations

Design: Strive for robustness

• Important issue in the selection and combination of steps

• Rarely addressed systematically

• Safety margins based upon experience

• Trade-off between performance and robustness Operations:

• REACT to uncertainties feedforward and feedback

• Requires margins• e su sequen c ose - oop opera on s ou e exp c y

taken into account in plant and process design currentl not industrial ractice


NY

D

DN

NY

Y3



Feedback Control: The Main Means toCounteract Uncertainties

Feedback control is mostly taught as methods to achieve goodresponses to reference signals

However its main function is to counteract uncertanties

•

• Disturbances

(Only) since the 1980s, the issue of the robustness of feedbackoops w t respect to mo e errors as een treate systemat ca yin the scientific literature, starting with:

George Zames: Feedback and Optimal Sensitivity - Model-ReferenceTransformations, Multiplicative Seminorms, and Approximate InversesIEEE Tr. on Automatic Control 26 (1981)

Mature theory for linear systems


NY

DDNN

YY4



Example: Plant PT1 with P-controller

Plant Step Response

2)200)(10(

)(

ss

K sG

p

P10

)(

s

K sG

p

P

1.0

0.9

0.8

0.7

0.6 i t u d e K

p= 7,5

1.0

0.9

0.8

0.7

0.6Kp = 7,5

Kp = 50.5

0.4

0.3

0.2

0.1

A m p l

Kp = 2,5

0.5

0.4

0.3

0.2

0.1

Kp = 5

Kp = 2,5

4

0.1 0.2 0.3 0.4 0.5 0.6

Closed Loop Step Response with P-controller (Kc = 70)

0 0.1 0.2 0.3 0.4 0.5 0.6

Time0

Time

3

2

1

.

0.9

0.8

0.7

0.6

0.5 l i t u d e

0

-1

-2

0.4

0.3

0.2

0.1

A m


NY

DDNN

YY5

0 . . . . . .. . . . . .



Example: Control of a Reactive Distillation Column

2kMeOH + HAc MeAc + H OCoolantCoolant

X

L

separation, azeotropes are

overcome by reaction

Reflux

Split

G

T1

T2T3

Semi-batch mode

Manipulated variables

• Reflux ratio RT

Acetic AcidTop Product

T6

T5

T7

T4

T8

• Feed (HAc)• Heat flow

T10

T9

T11

T12

• xMeAc

• xH2O

• emperatures a ong t ecolumn

Heat supply


NY

DDNN

YY6



The Reactive Distillation Column

Pilot plant:

• Diameter: 100 mm

• Height: 9 m

Cooperation• Fluid Separation Processes

Group

Group

In previous work, controllersthat were successful for

simulation models did notwor a e rea p an

Plant-model mismatch!


NY

DDNN

YY7



Plant operation (I)

2k

MeOH + HAc MeAc + H O

Concentrations in the

condensate (top of the c.)

o f t h e

e a m

MeAc

D

C o m p o s i t i o n

p r o d u c t

s t

H2OMeOH

e f l u x r a t i o

HAc

Heating power [kW]

Feed (HAc) [mol/ min]Time [h]


NY

DDNN

YY8



Plant operation (II)

2k

MeOH + HAc MeAc + H O

from the reboiler

p o r

o s i t i o n MeOH

o

V a

c o m p H2O

R e f l u x r a t i

Heating power [kW]

Feed (HAc) [mol/ min]


NY

DDNN

YY9



Disturbance Scenario


NY

DDNN

YY10



Process Operation Is More Than Control

O timization off-line, on-line

Data Reconciliation

State Estimation for Monitorin and Control

Process Performance Monitoring

Process Simulation

Operator Training Systems

Mana ement Execution S stems

SPC / Six Sigma


NY

DDNN

YY11



Lecture Outline

Week Date Content Lecturer

1 10.10.2011 Introduction, Control Structures 3L Dünnebier/ Engell

. .

3 24.10.2011 Tutorial: Control Structures 3T Tutors

4 31.10.2011 Introduction to Optimization, Linear Programming 3L Engell

5 07.11.2011 Nonlinear Programming 3L Engell

6 14.11.2011 Tutorial: Linear & Nonlinear Programming 3T Tutors

7 21.11.2011 Dynamic Optimization 2L + 1T Engell / Tutors

8 28.11.2011 Model Predictice Control, State Estimation 3L Engell9 05.12.2011 State Estimation 3L Engell

. .

11 19.12.2011 Real Time Optimization, Data Reconciliation 2L + 1T Engell / Tutors

12 09.01.2012 Process Performance Monitoring 2L + 1T Dünnebier13 16.01.2012 Process Simulation, Operator Training Systems, MES Dünnebier

14 23.01.2012 SPC / Six Sigma Dünnebier

15 30.01.2012 Operation of Life Science Processes, Wrap up Dünnebier / Engell


NY

DDNN

YY12



Department of Biochemical and Chemical Engineering

Process D namics and O erations Grou DYN

Lecture & Tutorial: Mondays, –

Lecture: ZE15

Tutorial: ZE15 / PC Pool I & III

Examination: 15.02.2012, 9am

DN

YDD

NNYY

Process Perf Opt Intro 2011

Documents

Transcript of Process Perf Opt Intro 2011