Reevaluating Advanced Control of the Ammonia Process JAMES GREMILLION

Emerson Process Management

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 2

The beginnings of Digital Control

1964 IBM 1800 Process Control

Computer Developed

1966 IBM 1800 controls the Borden

Ammonia Plant

1969 Control results in a 2-4%

increase

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 3

0

10

20

30

40

50

60

70

1955 1965 1975 1985 1995 2005 2015

Ammonia Production Efficiency

Gigajoules/Metric Ton Thermodynamic Limit

Production Efficiency Over the Years

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 4

Jupiter Ammon

Sal Ammoniac

Ammonia Plant

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 5

The Ammonia Plant at Jupiter Ammon

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 6

The Ammonia Plant at Jupiter Ammon

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 7

Water-to-Feed Ratio Reaches an Optimum

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 8

Fire-to-Feed Ratio Reaches a Constraint

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 9

A Well-Behaved Loop

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 10

The Process Control Loop

Two-thirds of control loops dont perform and some even make the situation worse

IFAC

In that control loops ultimately carry out most business decisions made in a refinery, chemical plant, paper mill, or power plant, its very alarming that two-thirds of all control loops perform in a disruptive or ineffective manner.

Industrial Computing

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 11

The Causes of Variability in Control

Valve Problems

Controller Tuning Problems

Transmitter Problems

Interactions

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 12

An Example of Control Loops Interacting

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 13

A Matrix Controller Reduces Interaction

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 14

Reducing Variability -Closer to Optimum

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 15

Closer to Optimum = More Production

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 16

Reducing Variability -Closer to Constraint

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 17

Closer to Constraint = More Production

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 18

The Causes of Variability in Control

Valve Problems

Controller Tuning Problems

Transmitter Problems

Interactions

80-90%

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 19

The Process Control Loop

Two-thirds of control loops dont perform and some even make the situation worse

In that control loops ultimately carry out most business decisions made in a refinery, chemical plant, paper mill, or power plant, its very alarming that two-thirds of all control loops perform in a disruptive or ineffective manner.

Industrial Computing

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 20

A Well-Behaved Loop

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 21

An Example of a Problem

PUMP

MAINTENANCE

INSTRUMENTATION

MAINTENANCE

SYSTEM

INTERACTION

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 22

A Never-Ending Process!

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 23

Modern DCS have the tools for basic loop problem management

Loops in Manual Loops not in Cascade Loops Oscillating

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 24

Control Performance Consultant

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 25

Entech Toolkit Analyze Functions

Time Series Plots Auto-Correlation Power Spectrum Analyses Integrated Power Spectrum Cross-Correlation Histogram Statistical Data (mean, 2-Sigma, % 2-Sigma) Power Spectrum Peak Picking and many other functions

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 26

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 27

Get the 80%!

Valve Problems

Controller Tuning Problems

Transmitter Problems

Interactions

80-90%

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 28

Control Performance Consultant

Two to Five Days

Find the worst-offenders amongst interactions and fix them through advanced tuning techniques or by using a matrix controller (APC)

Demonstrate techniques and document results

[File Name or Event] Emerson Confidential 27-Jun-01, Slide 29

A Never-Ending Process!

Continuous, Never-Ending Effort

Continuous, Never-Ending Benefit