Strategic Solutions through Optimization Science 1 REX Software Architecture REX LIBRARY Experimental Data + Guess of Reaction Mechanism Corporate Knowledge

Strategic Solutions through Optimization Science1

REX Software Architecture

REX LIBRARY

ExperimentalData

+Guess ofReaction

Mechanism

Corporate Knowledge Asset

Chemical Reaction KineticsDatabase

REXEstimation

Mechanism DiscoveryKinetic Estimation

Virtual CaseExperimentation Studies

Reactor Optimization- Static and Dynamic

KineticModel

REXSimulation

REXOptimization

Discover Clarify Design


REX Architecture

REX_Library and REX_Projects are independent products Each Company can set up their own REX_Library

REX_Projects has access to the Database for the REX_Library, so that users can import information from the Library(optional)


REX Software Architecture

Database oriented All Project Information is stored in a Relational Database

rather than in individual project files

User Interface Built on the Optience Core Platform

What is Optience Core Platform ? A user interface builder engine that:

» Allows User to Connect to Databases, Mathematical Solution Engines

» Allows to conveniently interact with the Database in order to add, modify and manipulate its content

The platform for building most applications at Optience


Data Architecture+

Data Storage

MathematicalModels and

Solution Engines

User Interface(.core)File

REX_Library

REX_Library

[………] [………]

Optience REX Software Architecture

Data Architecture+

Data Storage

MathematicalModels and

Solution Engines

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TIE

NC

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OR

E P

LA

TF

OR

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User Interface(.core)File

REX_Projects

REX_Projects

DB Engine

DB Engine

Database

Database


On REX Installation

Typical Installation in : C:\Program files\Optience Corporation

» Optience Core Components

» \REX DBs– All Project Data is stored here : REX_Projects.mdf– Default local REX Library is stored here : REX_Library.mdf

» \REX UIs– User Interface Components :

» REX_Projects.core

» REX_Library.core

» Compare_Projects.core

» \REX Models– Mathematical models and solution engine files

» \REX DLLs– Associated Dynamic Link Libraries


Typical screen in REX Projects(1) – Tree based

DB Engineon Desktop

VIEWS

APPLICATIONS

Save Formats(Disabled)

Help for Active Application

Tree Refresh

FILE BAR

RUN-TIMETREE

GRIDS

F1 key Help for Active Grid

Tabs


A typical View in REX Projects(2)

The File Bar and Run-Time Tree may be hidden to save screen space. They ‘reappear’ on a mouse ‘move over’


REX Projects

Top Menus Such as File, Edit, View Help are associated with the Core

Platform Example: “File -> Open” will be used only if we send you a

New Optience product that you need to open in Core Platform

Using REX_Projects Top Menus will be rarely needed All user interaction is in the Views, Tree Nodes, Grids, and

Actions » (Action is the PopUp Menu on Right Clicking a tree node)» Nodes with Actions are suffixed with “>>” characters

Example – Adding a Project» Go to Project Explorer View – Projects Node» In the Available Projects Grid – Add a new project» Go to the New Project Node – Fill the tree for the project


Project Data Entry

As you build your estimation project, data is saved automatically to the REX_Projects.mdf file in your REX DBs directory

All projects are saved in the same place, so when you open REX_Projects, you will automatically see all the projects in the database

Techniques to export, import, backup and manipulate projects will be shown later


Additional Information

See the REX_Projects help Documentation – F1 on any grid gives information specific to that grid


Estimation with REX

Ethylene Oxide to Ethylene Glycol

Purpose

Explaining the basic procedure to use REX


Kinetic Estimation with REX Suite-I

Objective Learn Problem Setup for Estimation Projects

Tutorial with a simple example. Ethylene Oxide Hydration to Ethylene Glycol*

If you have REX on your PC, you may follow along Illustrates the estimation of kinetics from Batch

Reactor Data Experiments in aqueous excess with H2SO4 cat. Data trend shows H2O effect on reaction negligible

*From Fogler et. al, Elements of Chem. Reaction Engineering


REX Projects - Project Explorer View

Add a project EOEG » Note the following behavior in every grid

– New information entry has an * in the row header– When editing, the * changes to a pencil: – To enter the information, hit <Enter> OR Click on the pencil– To undo, hit ESC


REX Projects – Project Explorer View

Here the projects that are ‘active’ are displayed in a tree

Select Project: EOEG Note the information grids in the right

Before we continue, a brief explanation on color coding and common features


REX Color Codes

REX has three different formats of grids with three different colors respectively. Orange: Orange grids are independent grids and they are

used to insert or to show the key information in each node Blue: Blue grids are dependent grids. A blue grid usually

shows information for a row selected in an Orange grid. Gray: Gray grids are OPTIONAL documentation grids, and

they show additional information which it is not necessary for the modeling. These grids usually have an {i} symbol in their Caption.

REX uses 3 font colors Black font is used to show data that can be inserted or

modified. Blue font is used to show data that is ‘Read only’ information Red font is used to show inconsistent data.


REX Color Codes & Help

You may select help with the F1 key on any grid

You may Filter information in a grid: By right-clicking on the Grid and

selecting filter Arrange by columns such as type by selecting the “Group by”

popup, and dragging a column to the gray area

RESET LAYOUT (an Action on Node Right Click) will reset everything to the default Very useful after modifying default options (OR) When the layout format looks abnormal


Restoring Default Layout

When several layout changes have been done,

they can be reverted by the

“View Layout Reset Layout for All Nodes” option:


Project EOEG - Compounds

We will add three compounds directly» Ethylene-Oxide (ETO), Ethylene-Glycol (ETG) and Water

A note on import from REX Library (not commonly used) If we had the EOEG Reaction Set in the Library, we could

import the chemistry directly » Check Enable Library in the Projects Node

» Under Chemistry Import from Library :– Check the ‘Select’ column for the desired Reaction Set– Execute Action “Import Reaction Set”

» Similar procedure if you wish to only import Compounds– Under Compounds Import from Library:


Compounds


Reactions

Add reaction by name: EtOtoETG Describe this reaction in the Stoichiometry Grid

EtO + H2O EtG


EOEG project

Browse through the catalysts and conditions {i} grids Enter Kinetics:

Select » Rate Equation; Mass Action

» Specific Rate: Arrhenius

Include Flag:» Note that only forward reactions are included by default

» Allows you to keep a reaction but make it kinetically absent– For example, you may want to test a simulation by removing a

reaction, instead of deleting it and writing it again, you may just change the include flag.


Units Configuration

Purpose: Change the Units of the Basic Variables What does REX do with this information ?

» REX uses this basic information to come up with the units for derived variables and show them

» For example: If Volume Units are in lit, Time in sec, Moles in mmol, Rate basis is Volume, REX will ask the user to provide

– Concentrations in mmol/lit– Flows in lit/sec– Rate Expressions in mol/lit-sec– …. and so on.

» REX attempts to display units clearly to the user in all data sheets to avoid potential mistakes in data entry

» Units Conversion is also performed here– Check the “Convert Data when changing units” box. – This converts all project data from old units to the new units


Units Configuration for this example


Kinetics Parameters >>

Reminder: A node with “>>” means it has an action in it Click on “Initialize Orders”

This sets the initial orders to be the same as the molecularity:

Reset the H2O order to zero since H2O is in excess and data trend analysis shows no impact of H2O

Enter some estimate of PreExponential Value -> Better to initialize away from 0


EOEG

LHHW and Kinetics Sites These are locked because there are no LHHW reactions

Notes Optional

Description of Chemistry is now complete

Proceed to Estimation: Activate Reactions to be Estimated


EOEG Project

Estimation Kinetics Execute >>

– Initialize Bounds Current Values Variables : All

Set PreExponential Factor Bounds between 0 and 1000%. Initial value at 0.1 or any non-zero number

So, we are now estimating only the pre-exponential factor

Reactor Reactor Type : Batch , PFR, n-CSTR Phase : Single Liquid Phase, Single Gas Phase, Multiphase Volume : Constant, Interpolate from Data, Use Density

Data/Correlations Temperature : Constant, Interpolate from Data Pressure : Free Fedbatch flows and Outflows : No, Yes


EOEG Project

Skip Flows and their sub-nodes Fedbatch flows have been set to No

Proceed to Experiments First Grid: Documentation

» Document the Experiment Design

» Lets assume the design is for varying inlet concentration of EtO


EOEG project

Design Description We will add just one set (set1) with a design EtO value of 1

gmol

Experiments Measurements Select the following as measured variables


EOEG Project

Measurements Set1 moles You may add data points for the batch reactor one-by-one

automatically Or >>Execute Action “Add datapoints”

» This allows you to add a few records and copy from excel

» We will add “6” additional DataPoints and copy the information below

Time (Minutes) Volume(lit) ETG (gmol) ETO (gmol) Water (gmol)0 1 0 1 50

0.5 1 0.1451 1 0.27

1.5 1 0.3762 1 0.4673 1 0.614 1 0.7156 1 0.848

10 1 0.957


0.5 1 0.1451 1 0.27

1.5 1 0.3762 1 0.4673 1 0.614 1 0.7156 1 0.848

10 1 0.957


0.5 1 0.1451 1 0.27

1.5 1 0.3762 1 0.4673 1 0.614 1 0.7156 1 0.848

10 1 0.957


EOEG Experiments

Experimental Data


Weights

Select only Ethylene Glycol for Reconciliation

The Grid Auto Generation Options shows different strategies for weighting

Uniform absolute error All measurements are assumed to have equal measurement error. So smaller measurements tend to get less importance.

» LSQ objective = i(Measi-Calci)2

Uniform percentage error All measurements are assumed to have equal percentage error. The square of this fractional error is minimized. Here, a 0.01 fit error in a measurement value of 0.1, is weighted 100 times more than a 0.01 error in a measurement value of 1.

» LSQ objective = i [ (Measi-Calci)2/ Measi2 ]

Hybrid: (Most common) Middle strategy between Uniform absolute and Uniform Percentage.

» LSQ objective = i [ (Measi-Calci)2/ Measi ]


EOEG - Weights

Select “Uniform Absolute Error” Execute Action : AutoGenerate

Note the History tab» Keeps history of alteration of the weights

See the generated weights in the Sets child node You may change the weights here through the “Modify

Weights” action or direct editing Unselecting the include flag for a point removes that point

from consideration in the estimation

Ready to now Run the Estimation model Before Running check for errors by:

» ‘Run Estimation Check Model’


EOEG – Run Estimation

To Run the Model, click the triangular play button

Run Options VCR Buttons

Purpose of saving is for technical support. You can save the run as an MOS file and email it, in the event of convergence problems

Run Cancel

Save Run

Interrupt


Results

View Parameters


Results

Model-Data Comparison Two tabs are available: Values and Charts

» Select Charts

Select Sets to View View Charts showing measured versus calculated values Double Click on Chart to customize chart styles

» Charts can be copied and pasted into Office programs

Try “Parity Plots” to see an overall comparison between measured and calculated profiles

Perform “Single Set” action to be able to display several compounds together for a given experiment set


Tuning the Solution Methods

Under Run Estimation Check Model Solution Options Initialization Values

» You may input the initial values here

or

» Load them from the previous solution– Estimation Initialize from Results

Try the EOEG example with profiles initialized by the previous results


Manipulating Projects (1)

By Default, all projects are stored in the REX_Projects.mdf

Now, we will learn to export and import projects From both Projects Node and Each Project



Most Export / Import activities are performed by Right Click Actions

» Choosing “False” for ‘Export results’ on export can save time and reduce the file size

» Likewise, choosing false for importing results can save time

You may also create a copy of a project by selecting the Copy action on the Project Name



Project Manipulation through Action menus Action Menus are also available in the Project Catalog.

These menu buttons allow you to perform import, export and common project operations with a single click.

Moving mouse over them shows the relevant actions


Task: Project Actions with EOEG project

Export the project from Project Explorer Re-import the project into your workspace Rename the Project Adding another experiment

In Experiments node, check the Mark Column for set1 Execute the “Copy Marked” Action

» All information related to the set from Experimental Data to Initialization Values and weights are copied

(You may edit this experiment and then run the model)


Generating Reports in Excel


Nifty Utilities

Copying whole sheets Click on top left corner – [CTRL–C]

Copying a column Click on column header – [CTRL-C]

Editing a cell Single F2 selects everything in cell Two consecutive F2 places cursor at last point in text ESC reverts changes to a cell

Selection of a Cell Range now available by many methods Drag and select , SHIFT-Arrows

Copy/Paste Keyboard (CTRL-C/V), Edit Menu, Toolbar Buttons

Documents

Strategic Solutions through Optimization Science 1 REX Software Architecture REX LIBRARY Experimental Data + Guess of Reaction Mechanism Corporate Knowledge