Title Getting Started with

PROVISION and PRO/II

2

Course Content

• Introduction

• Guided and Independent Exercises

• Simulation in Seven Steps

• Main Parts of a Simulation

– Components

– Thermodynamics

– Streams

– Phase Equilibrium Calculations

– Unit Operations

– Columns

3

A Brief History of Simsci-Esscor

• Simsci founded in Nov. 1966 by Dr. Wang

– SP03 - distillation program

• 1974: SSI/100 - first flowsheet simulator

• 1979: PROCESS - keyword, batch mode

• 1988: PRO/II - interactive

• 1995: PRO/II with PROVISION

– true 32-bit Windows-based application

• 1997: Simsci became a public company

4

• 1998: Simsci acquired by Siebe

• 1999: Siebe merged w/ BTR and renamed the company - Invensys

• 2002: Simsci & Esscor merge

• Today

– $5 Billion company located in UK

– Diversified Engineering and Electronics group

– Employs more than 30,000 people worldwide

A Brief History of Simsci-Esscor

5

PIPEPHASE

NETOPT

TACITE

Oil and Gas

Production

Simsci Solution Suites

PRO/II

HEXTRAN

VISUAL FLOW SUITE

INPLANT

DATACON

Process

Engineering

ROMeo

CONNOISSEUR

ARPM

On-Line

Performance

DYNSIM

FSIM

TRISIM

OTS

Dynamic

Simulation

Products fall into one of five

“Solution Suites”

COMOS FEED

iFEED

Introduction

7

PRO/II vs PROVISION

• PRO/II is the Calculation Engine

– Solves Equations

• PROVISION Makes PRO/II Easy to Use

– Graphical User Interface

• PRO/II 5.0+: Microsoft Windows 95 or NT

• PRO/II 5.1.1+: Microsoft Windows 2000

• PRO/II 5.6+: Microsoft Windows XP

• SIM4ME will be very similar to PROVISION

8

PRO/II Capabilities & Features

• Large component data bank and thermodynamics data bank

• Flexible and powerful refinery capabilities

• Reactive and electrolyte distillation modeling

• Regression and data management tools

• Advanced flowsheet sequencing capabilities

9

PRO/II Capabilities & Features

• PROVISION (GUI)

– 32-bit Windows-based application

– Interactive execution

– Graphs, tables and charts can be exported

– OLE functionality

10

Steady State Simulator

• No Time Dependent Phenomena

• Exception: Depressuring Unit

• Controllers & Instrumentation Are Irrelevant

11

Remove Control Valves and Instrumentation

TI TI PI PI

LC LC LC

12

Sequential-Modular Simulator

• Units solved one at a time

• Feeds must be known

• Recycles automatically handled

1

2 3

13

Desktop Environment

• Menu bar

• Toolbar

– Can easily access many of the menu functions

• Color Cues

– Indicates required data entry

• Palettes

– PFD

– Run

14

Desktop Environment

How to Do a Simulation in PRO/II

16

Simulation in Seven Steps

1

Build Flowsheet

Check Units of Measure

2

Define Components

3

Select Thermo

4

Supply Stream

Data

5

Provide Process

Conditions

6

Run & View

Results

7

17

Group Units if Desired

18

• Common Source of Errors

• English is Default

• Default Can be Changed Globally (all Future

Simulations)

• Can be Changed for Entire Flowsheet

• Can be Changed Locally

• Can Define Custom Set of UOM

Units of Measure

Components

20

Component Selection

• Pure component from a library

• User-defined component

• Petroleum component

21

Petroleum Components

• Normal Boiling Point

• Gravity

• Molecular Weight

At least two of three required

22

Simulate a Chiller Plant in 4 Parts

• Recover liquids & deliver gas to pipeline

C2

Pipeline Gas

T1 Stabilizer

M2

M1 Natural Gas

Liquids (NGL)

S14

S18 S20

S1

S19

V1

HX3

F3

Refrigerant

S12

S10 S11

S13

S17

F1

Cooling Air

S9

C1

HX1

F2 S2 S4 S5

S6

S7

S3

Inlet Gas

S8

HX2

S16

S15

S1

Selecting the Thermodynamics

24

K-Value Calculation Methods

• Ideal

• Equation of State

• Liquid Activity

• Generalized Correlations

• Special Packages

• Electrolytes

• Polymers

25

Selecting the Thermo Method

26

• Refining Processes:

– Grayson-Streed: Hydrogen rich systems, Crude tower, Vacuum unit, Coker fractionator, FCC main fractionator

– SRK and PR: Light ends columns, Splitters, Gas recovery plants, Hydrogen rich systems (SRKM)

– SOUR, GPSWATER: Sour water systems

– SRKK, SRKM, SRKS, IGS: Use if H/C solubility in liquid water (VLLE) is important.

Hydrocarbon Systems

27

Hydrocarbon Systems

• Gas Processing:

– SRK and PR: All types of processing plants, cryogenic systems

– SRKM, PRM, and SRKS: Systems with water, methanol, and other polar components

– GLYCOL: Dehydration with TEG. Improved for aromatic emissions. Based on SRKM.

– AMINE: Natural gas sweetening.

– SRKK, IGS, SRKM, SRKS: Use if light gas solubility in water (VLLE) is important.

28

• Non-ideal components

• Low to medium pressures

• Rely on binary interaction parameters (if missing will be close to Ideal!)

• Missing parameters estimated from structures, azeotrope composition, mutual solubilities etc.

• Used with Henry’s Law for non-condensibles

• VLLE with some methods

Chemical Systems:

Activity Coefficient Methods

29

Chemical Systems:

Activity Coefficient Methods

Two Binary parameters Liquids? in databank?

NRTL Yes Yes

UNIQUAC Yes Yes

WILSON No No

UNIFAC Yes Estimates non-ideality from structure

• Other methods - see Reference Manual

30

Chemical Systems: Equations of State

• SRK-SIMSCI, SRKM, and PRM for polar mixtures

• SRK-Hexamer for mixtures involving HF

• Can model high-pressures

• Also relies on binary interaction parameters

• Some binary parameters in databanks for above methods

Supplying Stream Data

32

Types of Streams

Internal Feed

External Feed

Product

Recycle

Product

33

Stream Attributes

• Thermal Condition

• Flowrate

• Composition

– Defined by components

– Defined by assay data

– Referenced to another defined stream

34

Stream Data

35

Thermal Condition Data

• Pressure

• Temperature

• Liquid Fraction or Phase

– Saturated liquid at bubble point

– Saturated vapor at dew point

Specify two of these three properties

36

• Satisfies a flowsheet specification by

manipulating an upstream parameter

• “Long-Distance” specifications and

variables

• Analogous to a process feedback

controller

Feedback Controller

Exercise: Chiller Plant - Part 3, p. 17

Add a controller

Distillation

39

Tray Numbering

• Normally use Theoretical Trays (Stages)

• Numbered from Top Down

• Condenser is Stage 1

– Even for subcooled condenser

• Reboiler is Last Stage

– Thermosiphon adds 2 stages

• Convert Packing to Stage:

– Rule of Thumb: 2-3 feet of packing per stage

– Modern structured packing could be inches, so check with

the manufacturer

40

Tray Efficiency

• Murphree yi,n = yi,n+1 + EiM

(yi,n*-yi,n+1)

• Vaporization yi = EiV Kixi

• Equilibrium Like EiV, but K’s - 1

• Vapor Leaving Stage not at Dew Point

• Can Lead to Mixed Phase Condenser Product

• Better to Use Overall Efficiencies

– Theoretical / Actual trays to carry out separation

– Use different values in different column zones

– Don’t forget condenser and reboiler!

41

Tray Efficiency

xA

75% efficient:

step 3/4 to

equilibrium curve

yA

xA

l

l

100%

efficient:

step to

equilibrium

curve

• Murphree: yi,n = yi,n+1 + EiM

(yi,n*-yi,n+1)

42

Typical Overall Efficiencies (%)

• Deethanizers: 60-65

• C3 Splitters: 95-100

• Crude Units:

– Stripping Section 30

– Flash Zone to Gas Oil 30-40

– G.O. Draw to Diesel Draw 40-50

– Diesel Draw to Kero Draw 45-55

– Top Section of Column 55-65

• Columns with reboilers and condensers: 60-80

• Pumparounds eliminate trays: 20-25

43

Condenser Options

• Available in all algorithms

• Partial

• Vapor overhead product

• If present, Liquid product is side draw from stage 1.

• In Keywords, two product condenser is called “Mixed”

Overhead

Overhead

Side-draw

44

Condenser Options (continued)

• Bubble

• Liquid product at bubble point

• Fixed temperature

• Sub-cooled at a specified temperature

• Delta T below bubble point

• Specify degree of subcooling

Overhead

45

N-1

Bottom Tray

N

Reboiler BTMS Q

VN-1 LN-2

VN LN-1

BTMS

LN-1

VN

Kettle Reboilers

Vapor in Equilibrium with Bottoms

46

BTMS

LN-1

VN

Bottom Sump Reboiler

Sump

Baffle

LN-1

VN

BTMS

Bottom

Sump

Single Pass (Once Through) Thermosiphon

• Equivalent to a Kettle Reboiler Because Bottoms is in Equilibrium with VN

47

N-2

Bottom Tray

N-1

Combined Sump

N

Reboiler

BTMS

Q

VN-1 LN-2

RL RF

R V

LN-2

VN-1

R V

RL

RF BTMS

Combined Sump

Circulating Thermosiphon Adds 2 Stages

• Simulate as TS without Baffles

48

BTMS

VN-1

Bottom Sump

RF

RV

RL

LN-2

Reboiler Sump

N-2

Bottom Tray

N-1

Reboiler Sump

N

Reboiler

BTMS

Q

VN-1 LN-2

RL RF

R V

Circulating Thermosiphon

Simulate as TS without baffle

49

BTMS R L

R F

L o

R V

N-2 Bottom Tray

N-1 Reboiler Sump

N Reboiler

Bottom Sump

Q

V N-1 L N-2

BTMS

L N-2

V N-1

Bottom Sump Reboiler

Sump

R F

R V

R L

L O

Preferential Thermosiphon

Simulate as TS with baffle

50

All Column Algorithms are Iterative

• Want to Solve f(x) = 0

• Generate a Sequence of Estimates of Solution:

x0, x1, x2, ... xN

• When all Equations are satisfied, i.e.

| f(xN) | < 0.001

• xN is Regarded as the Solution

51

Convergence of Newton’s Method...

x xf

xf xn n

x

n

n

1

1

( )

Solution

f(X)

0

X x1 x2 x*

Good initial guess

leads to solution

x0

52

Convergence is not guaranteed!

f(x)

x* X

0

53

f(x)

x* X

0

Periodic

Convergence is not guaranteed!

54

Bad guess

converges

But better

guess fails!

f(x)

x* X

0

Convergence is not guaranteed!

55

You Can Help I/O by Using DAMPING

• DAMPING Reduces Iteration Step and Suppresses

Oscillation

• Conventional Columns: DAMP = 1.0 (default)

• Columns with Steam: DAMP = 0.6 -- 0.8

– Crude, Vacuum, FCC Main Fractionator

• Highly Non-ideal: DAMP = 0.4 -- 0.6

– If Oscillation Persists, Use Chemdist

56

Distillation Algorithm Selection

• Generality.

• Total Pumparounds.

• VLWE on any Tray.

• Water draw from any tray

• Slow

• Sensitive to initial guesses

• Columns with free water or water draw on trays other than condenser.

• Total pumparounds or vapor bypass

Inside/Out (I/O) CHEMDIST

• Very fast

• Insensitivity to initial estimates.

• Thermo non-ideality.

• NO VLLE capability. (VLWE at condenser)

• Hydrocarbon Systems

• EOS & Slightly non-ideal LACT Thermo.

• Interlinked columns

• Side & main columns solved simultaneously.

• Reactive Distillation.

• VLLE on any tray.

• Highly Non-Ideal Systems.

• No Pumparounds.

• Side columns solved as recycles.

• Non-Ideal Systems.

• Mechanically simple columns

• VLLE within column

Unique

Features

Strengths

Limitations

Applicability

SURE

57

• Inside Out (I/O)

– Relatively Ideal Thermodynamics Including Hydrocarbon with Water Decant (Enhanced I/O can handle water on the trays)

– Incorporates Sidestrippers into column -- No recycle!

– Thermosiphon Reboilers

– Very Forgiving of Bad Initial Estimates

– Fast!

– No VLLE

Distillation Algorithm Selection

58

• Chemdist

– Mechanically simple columns, complex

thermo

– True VLLE

– Azeotropic and Reactive distillation

– Sidestrippers solved by recycle

– No Pumparounds or Thermosiphons

– More sensitive to Bad Initial Estimates

Distillation Algorithm Selection

59

• Sure

– Very General: Complex Column and Thermo

– Use when I/O and Chemdist do not apply

– Newton Method

– Very sensitive to Bad Initial Estimates

– Side columns are solved as recycles

– Allows free water or water draw on trays other than

condenser

Distillation Algorithm Selection

Exercise: Chiller Plant - Part 4, p. 21

Add a column and compressor

62

Output Options

• Export via Windows Clipboard

– Data in Spreadsheets

– Graphics

• Plots

• Output Files

• Stream Property Tables

• Unit Operation Tables

• Case Studies

64

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