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Process Simulation, Unit Operations Design and CFD

Flowsheet Simulation, Detailed Design and Operational Options

Mike Mendez

Aspen Technology, Houston, TX

April 2017

© 2015 Aspen Technology, Inc. All rights reserved 2

Disclaimer

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developments including new products, product features, product interfaces, integration,

design, architecture, etc. that may be represented as “product roadmaps.”

Any such information is for discussion purposes only and does not constitute a

commitment by Aspen Technology to do or deliver anything in these product roadmaps

or otherwise.

Any such commitment must be explicitly set forth in a written contract between the

customer and Aspen Technology, executed by an authorized officer of each company.


Topics

• Scope of Process Simulation

– Heat and Material Balances

– Equipment Selection and Sizing

– Cost Estimation

– Operations Support

• Engineering Work-process Discussion and

Demonstrations


Conceptual Design

Data and MethodsReactions

Heat and Material Balance, Flowsheet


What Equipment is Required?

Equipment Selection, Design and Cost Analysis

How Much Will it Cost?

What is the Right Size


Models in Process Operation and Optimization

ProcessModel

RTO

OperatorAdvisory

DecisionSupport

ProcessInferential

EquipmentMonitoring

DataReconciliation

OperatorTraining

Planning

Drive process closer to its constraints to increase profit

Track state of key equipment

Visualization & What-if analysis

Provide real-time operating advice

Use models as virtual sensorsClose mass &

energy balance

Teach engineers & operators how to run the plant

Use models to actualize planning models


Conceptual Design Workflow

• Identify the appropriate Physical Property Package

• Assess the quality of available VLE/LLE data

• Identify the best reaction sequences

• Select the most effective separation methods

• Develop the flowsheet and apply PINCH analysis

• Select equipment, size and do preliminary cost analysis


Select Components

Conceptual Design Workflow – Select Components


Other Special Types of Components

Ions and salts that react Polymers with MW Distribution


Design Workflow – Solid Components with PSD

Solid components may have particle size distribution (PSD)


Special Methods for Non-Conventional Components

C

O2

N2

H2

H2O

S

CL

……

?

• From “Substance” to molecules ?

• Thermodynamic Properties ?


Select Property Method

Suitable for Process or

Component Set

Conceptual Design Workflow – Select Properties Methods


Check for Physical Property

Parameters and Data for all

Key Components

Conceptual Design Workflow – Data Availability and Quality


Property Parameters Required for Mass and Energy Balance Simulations

If you

These parameters are

required

Enter them on this type of Methods |

Parameters form

Use the standard liquid

volume basis for any

flowsheet or unit operation

model specification

Standard liquid volume

parameters (VLSTD) Pure Component | Scalar

For simulations that involve

both mass and energy

balance calculations, you

must enter or retrieve from

the databanks these required

parameters:

This table gives further

information:

For simulations that involve

both mass and energy balance

calculations, you must enter or

retrieve from the databanks

these required parameters:

This table gives further

information:

For simulations that involve both mass and

energy balance calculations, you must

enter or retrieve from the databanks these

required parameters:

This table gives further information:

For simulations that involve both mass and energy balance calculations, you must enter or retrieve from

the databanks these required parameters:


Property Parameters Required for Mass and Energy Balance SimulationsThis table gives further information:

Enter or retrieve

this parameter For

On this type of Methods |

Parameters form

MW Molecular weight Pure Component | Scalar

PLXANT

Extended Antoine vapor

pressure model Pure Component | T-Dependent

CPIG or CPIGDP Ideal gas heat capacity model Pure Component | T-Dependent

DHVLWT or

DHVLDP Heat of vaporization model Pure Component | T-Dependent


• Supplement missing data with published data or DECHEMA

• Generate missing parameters from data using Data-Regression

• Estimate parameters from molecular structure as method of last resource

Properties from molecular structure

Conceptual Design Workflow - Supplement Missing Data


Conceptual Design Workflow - VLE / LLE Analysis

Residue Curves

T-xy diagram for BUTANOL/WATER

Liquid/vapor mole fraction, BUTANOL

Tem

pera

ture

, C

0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350 0.400 0.450 0.500 0.550 0.600 0.650 0.700 0.750 0.800 0.850 0.900 0.950 1.00092

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

x 1.0133 bar

y 1.0133 bar

Txxy Binary Diagram

Activity Coefficients at Infinite Dilution

Use binary and ternary

analysis tools to reveal

azeotropes, solubilities,

and VLLE boundaries


THE IMPORTANCE OF ACCURATE PROPERTY CALCULATIONS

Resulting % Error

Property %Error Equip. Size Equip. Cost

Thermal Conductivity 20 13 13

Specific Heat 20 6 6

Latent Heat of Vap. 15 15 15

Activity Coeff. 10

Sep. factor = 50 3 2

1.5 20 13

1.2 50 31

1.1 100 100

Diffusivity 20 6 4

100 40 23

Viscosity 50 10 10

Density 20 16 16

Surface Tension 20 9 9

(Ref. Advanced Process Engineering, AICHE, James Fair)


Conceptual Design Workflow - VLE / LLE Analysis

Activity Coefficient at Infinite Dilution


Conceptual Design Workflow – Reactions and Kinetics

Equilibrium and Kinetic Reactions Kinetic Reaction Types

Reactors are the heart of the process, choose wisely


Conceptual Design Workflow – Biological Reactors

Equilibrium and Kinetic Reactions Kinetic Reaction Types

Reactors are the heart of the process, choose wisely


Fermentation models require special methods


0

2

4

6

8

10

12

14

16

0 20 40 60 80

0

50

100

150

200

250

B

I

O

M

A

S

S

o

r

E

T

O

H

R

a

t

e

t, hours

S

U

G

A

R

o

r

E

T

H

A

N

O

L

Ethanol (g/L) Sugar (g/L) Biomass (g/L) ETOH Rate, g/L-hr


Logistic Model With Growth Associated Production of Ethanol



Conceptual Design Workflow - Separation and Purification

STRIPR

RECTIFR

BEERCOLPUMP

RECBTMS

RTRN

STRIPBTM

BCOVH

RECOVHD

FUSEL-O

S-1

BEER

BCBOTM

Distillation

EXTRACT (Extract) - Profiles Composition

Stage

WA

TER

MTB

E

CO2

1 2 3 4 50.00565

0.00570

0.00575

0.00580

0.00585

0.00590

0.00595

0.00600

0.00605

0.00610

0.00615

0.00620

0

2.50e-6

5.00e-6

7.50e-6

1.00e-5

1.25e-5

1.50e-5

1.75e-5

2.00e-5

2.25e-5

2.50e-5

2.75e-5

3.00e-5

3.25e-5

3.50e-5

3.75e-5

0.99380

0.99385

0.99390

0.99395

0.99400

0.99405

0.99410

0.99415

0.99420

0.99425

0.99430

0.99435

CO2

MTBE

WATER

EXTRACT

CO2

MTBE

L1

L2

Liquid-Liquid Extraction

Adsorption

CRYSTAL

HYDROCYC

DECANTER

63

CRYSTALS

10

SOLUTION

S4

63S6

S1

0

S8

S45

Crystallization


Distillation Design

Enabling Functions:

Separations Synthesis Design and Rate-Based

Distillation

Useful for devising new separation schemes or improving

existing ones. Might help reduce the number of columns in

complex separations trains and still maintain the same quality

of product.

Distillation Synthesis• Conceptual design of distillation

systems, most useful for nonideal, azeotropic mixtures

• Visibility into ternary and residue diagrams.

• Integrated with steady-state simulation tools

Rate-Based Distillation• Calculate Mass and Heat transfer

rates

• Work with real column internalsrather than theoretical stages

• No need to guess separation efficiencies


Conceptual Design Workflow – Flowsheeting and Pinch Analysis

DemethanizerDeethanizer C2-Splitter

Hydrogen

Gas from Furnace

Ethylene

EthaneEthane

To Depropanizer

Chiller 3Chiller 5 Chiller 1 Chiller 4 Chiller 2

Ethylene Plant Cold End Flowsheet

Pinch – Grand Composite Curve Pinch – Heat Exchanger Network


Conceptual Design Workflow – Heat Exchangers

Air CooledFired

Heater Plate

ExchangerPlate Fin

Shell & Tube

Shell & Tube

Mechanical

Heat Exchangers - Design, Rate and Simulate


Rigorous Exchanger Models in Flowsheet Simulations

Analyze Risk and Potential Operational Problems of Heat Exchangers

Exchanger Feasibility

Identify Operating Risks


Enabling Function

Dynamic response of systems (equipment and

controls)

Configure process control schemes that yield

more stable systems, and get you closer to

optimal operation.

Dynamic Simulation

prod

Time Hours

ST

RE

AM

S("

RE

CO

VH

D")

.Zm

n("

H2O

") lb

/lbS

TR

EA

MS

("R

EC

OV

HD

").Z

mn

("F

US

EL

") lb

/lb

ST

RE

AM

S("

RE

CO

VH

D")

.Zm

n("

ET

HA

NO

L")

lb/lb

ST

RE

AM

S("

RE

CO

VH

D")

.Zm

n("

CO

2")

lb/lb

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6

0.84

0.86

0.88

0.9

0.92

0.94

0.0

0.00

:0.

020.

030.

040.

050.

060.

070.

080.

09

RECTIFIER

Time Hours

ST

RE

AM

S("

RE

CO

VH

D")

.Zm

n("E

TH

AN

OL"

) lb

/lb

0.4 0.9 1.4 1.9 2.4

0.85

0.86

0.87

0.88

0.89

0.9

0.91

0.92


Conceptual Design Workflow – Project Costs

Equipment Mapping Equipment Cost

Relative Project Cost


Activated Cost Project Summary


Capacity Scaling and Capital Costs with ASW

Cost estimation

results shown in ASW


Models for Uncertainty Quantification or Global Optimization

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

1 91

72

53

34

14

95

76

57

38

18

99

71

05

113

121

129

137

145

153

161

169

177

185

193

Rxn Conversion Variability

0

20

40

60

80

100

120

140

0

0.0

4

0.0

8

0.1

2

0.1

6

0.2

0.2

4

0.2

8

0.3

2

0.3

6

0.4

0.4

4

0.4

8

0.5

2

0.5

6

0.6

0.6

4

0.6

8

0.7

2

0.7

6

0.8

0.8

4

0.8

8

0.9

2

0.9

6 1

Rxn Conversion Frequency

RXT

FEED

PRD

Three Simultaneous Reactions

Uncertainty in Rxn Kinetic ParametersBatch Reactor


Model Automated with EXCEL to Find Local and Global Optima


Reliability, Availability and Maintenance


RAM Modeling


System and Reliability ModelingUtilizes Unit Histogram


System and Reliability ModelingPareto (Top 10)


RAM Modeling – Power/Cogen

• During the design phase of a power generation facility, our RAM Modeling was used to determine if a utility grid connection would provide adequate electrical reliability. This option was compared to one with self-generation. For these cases, the model determined that the utility grid did provide adequate reliability and that the additional cost of adding on-site generators was unnecessary. This proved to be a significant costsavings to the company.

• When designing a new steam generation facility, our RAM Modeling was used to determine the size and optimal number of steam boilers. After running several alternate cases with many different size differentials and configurations, the model landed on the most economical design that would provide the required level of reliability. This could be completed for any utility plant such as air compression, power generation, co-generation, or even water supply & treatment.

• During the operational phase of many utility plants, demands for electricity, stream, and instrument air often increase as the customer plants grow and increase production. Our RAM Modeling has been used to help evaluate many different de-bottleneck alternatives. When the desired reliability of each alternative is achieved, completing a cost analysis is an easy way to select the most economical solution. Some examples ofthis may include:

– Selecting a vendor for a new skid

– Installing stand-by generation or diesel backups

– Connecting to a standby utility header

– Improving site recovery methods.


Questions

process simulation, unit operations design and cfd · pdf fileaspen technology may provide...

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