CHEN 4460 – Process Synthesis, Simulation and Optimization

CHEN 4460 – Process Synthesis, Simulation and Optimization

Dr. Mario Richard EdenDepartment of Chemical Engineering

Auburn University

Lecture No. 1 – The Design Process

August 21, 2012

Contains Material Developed by Dr. Daniel R. Lewin, Technion, Israel

Class Overview & Introduction

• Background– M.Sc. (Chem. Eng.), Tech. Uni. of Denmark

(1999)– Ph.D. (Chem. Eng.), Tech. Uni. of Denmark

(2003)

• Professional Experience– Department Chair, Auburn University (2012 –

Present)– Professor, Auburn University (2012 – Present)– Associate Professor, Auburn University (2008 –

2012)– Assistant Professor, Auburn University (2004 –

2008)– Visiting Lecturer, Auburn University (2002 –

2003)

My Background

Where is Denmark?

A Few Facts about Denmark

My hometown

Where I moved to go to college

Constitutional Monarchy

A little smaller than the state of Alabama

(not including Greenland)

Population approximately 5500000.

National sport – SOCCER!

• Computer Aided Process Engineering– Property prediction & CAMD for solvent

selection/design– Process modeling and simulation

• Process/Product Synthesis and Design– Develop novel efficient methods for emerging

problems– Develop strategies for simultaneous solution– Systematic identification/generation of

alternatives

• Process Integration and Optimization– Application of holistic methods to ensure

sustainability– Fuels reforming and biorefinery optimization

My Research Interests

• Lectures (Start Today)– Tuesday 9:30 – 10:20 AM (Ross Hall 136)– Additional recitation lectures during lab sessions

• Labs (Start Today)– Sections

• I: Tuesday & Thursday 11:00 AM - 12:20 PM (Ross 306)• II: Tuesday & Thursday 6:30 PM - 7:45 PM (Ross 306)• Large part of labs consist of multimedia based

instruction• Headphones are available upon request

• Homework– Assigned for both lecture and lab parts – Some homework assignments can/should be

solved using Aspen

Class Overview 1:3

• Teaching Assistants– Dr. Zheng Liu Mr. Alexander Kelly

• Office hours: Wed. 1:00–3:00 PM Office hours: TBA• Ross 349 Location: TBA

– Ms. Zhelun Li• Office hours: TBA• Location TBA

• Course Materials– Textbook

• Seider, W.D., J.D. Seader, D.R. Lewin, S. Widagdo “Product and Process Design Principles”, 3rd edition Wiley (2008).

• Eden, M. R. "ASPEN Lab Notes", Auburn University (Posted as PDF on class webpage).

Class Overview 2:3

• Grading– Simulation Project (10%)– Homework (10%)– Midterm (30%)– Final exam (50%)

• Instructors Office Hours– Official: Tuesday 1:00 – 3:00 PM– Reality: Any time the door is open

Class Overview 3:3

Tentative Class ScheduleDate Topic Reading Homework Due 8/21 #1: Course Introduction and Overview

Introducing Simulation Multimedia Package Introducing Design and Synthesis Process

SSLW Chapter 1 Pages 1-31

8/28 #2: Process Creation Preliminary Database Creation Preliminary Process Synthesis Development of Base-Case Design

SSLW Chapter 4 Pages 77-94, 101-109

9/4 #3: Heuristics for Process Synthesis Chemical Reaction Mixing and Recycle Separation Temperature, Pressure and Phase Change Task Integration


9/11 #4: Algorithmic Methods for Process Synthesis – Part I Reactor Design and Reactor Network Synthesis Synthesis of Separation Trains

SSLW Chapter 7+8 Pages 181-216

9/18 #5: Algorithmic Methods for Process Synthesis – Part II Sequencing of Ordinary Distillation Columns


9/25 #6: Review of Thermodynamics of Non-Ideal Mixtures Azeotropy Residue Curves Distillation Boundaries


#1: 8.1, 8.2, 8.3

10/2 #7: Algorithmic Methods for Process Synthesis – Part III Separation of Non-Ideal Mixtures

Review for Midterm Exam


#2: 8.14b-d, 8.15

10/9 Midterm Exam 10/16 #8: Mathematical Optimization

Solution of LP, NLP, MILP, MINLP Introducing LINGO Solver Software


10/23 #9: Heat and Power Integration - Targeting Temperature Interval Method Composite Curve Method Thermal Pinch Analysis


#3: 24.1 + Handout

10/30 AIChE Annual Meeting, Pittsburgh, PA 11/6 #10 :Heat and Power Integration – Network Design

Maximum Energy Recovery Networks SSLW Chapter 9 Pages 261-280

11/13 Class Review #4: 9.1, 9.2 11/20 Thanksgiving Holiday 11/27 Class Review 12/3 Final Exam (8:00 – 10:30 AM)

Week Dates Lecture and Multimedia Material Computer Exercises 1 8/16 No labs 2 8/21, 8/23 MM: Principles of Flowsheet Simulation

Getting Started in Aspen o Brief Introduction o Setting Up o Sample Problem

SSLW Chapter 5, pp. 110-120

MM: Tutorials Material and Energy Balances

o Ammonia/Water Separation

3 8/28, 8/30 MM: Principles of Flowsheet Simulation Getting Started in Aspen

o Convergence

SSLW Chapter 5, pp. 120-131

MM: Tutorials Material and Energy Balances

o Ethylchloride Manufacture

Homework #1 (Due Week 4 in lab) Exercise A.1 (Aspen Notes)

4 9/4, 9/6 Lab Recitation Lecture #1 Heuristics for Process Synthesis

MM: Pumps, Compressors and Expanders

Overview o Pumps o Compressors and Expanders

MM: Heat Exchangers

Overview o Introduction o Heat Requirement Models o Shell-and-Tube HX o Multiple-Stream HX

5 9/11, 9/13 MM: Separators Overview

o Phase Equil. And Flash MM: Physical Property Estimation

Overview o Property Estimation

Phase Equilibria Equil. Diagrams Property Data Regression

Homework #2 (Due Week 6 in lab) Exercise B.1 (Aspen Notes) Exercise B.2 (Aspen Notes) Exercise B.3 (Aspen Notes)

6 9/18, 9/20 Lab Recitation Lecture #2 Separation Trains

MM: Tutorials Heat Transfer

o Toluene Manufacture 7 9/25, 9/27 MM: Separators

Overview o Introduction o Split-Fraction Model (SEP2) o Phase Equil. and Flash o Distillation

MM: Tutorials Separation Principles

o Flash and Distillation Flash Distillation

Tentative Lab Schedule

MM: Multimedia material to review using headphones at your own pace.

MM Tutorials: Perform simulation while following multimedia presentation.

Week Dates Lecture and Multimedia Material Computer Exercises 8 10/2, 10/4 Lab Recitation Lecture #3+4

Azeotropic Distillation Choosing Property Models

MM: Physical Property Estimation

Property Package Selection

Homework #3 (Due Week 9 in lab) Exercise D.1 (Aspen Notes)

9 10/9, 10/11 MM: Chemical Reactors Overview

o Introduction o Stoichiometric Reactors o Equilibrium Reactors o PFR o CSTR

MM: Tutorials Reactor Design Principles

o Overview Theory Setting Up Reactors

10 10/16, 10/18 Lab Recitation Lecture #5 Introducing LINGO

Lab Recitation Lecture #6 Solution for Midterm Exam

MM: Tutorials Reactor Design Principles

o Ammonia Converter Homework (Due 10/23 in class)

SSLW 24.1 Problems in Handout

11 10/23, 10/25 Homework #4 (Due Week 12 in lab) Exercise E.1 (Aspen Notes)

12 10/30, 11/1 Lab Recitation Lecture #7 Simulation Project Overview Preparing Reports

Simulation Project Report due 11/29 Build Steady State Simulation

13 11/6, 11/8 Lab Recitation Lecture #8 Heat Integration

Simulation Project Finalize Initial Simulation Perform Integration Analysis

14 11/13, 11/15 Simulation Project Simulate Integrated Process

15 11/20, 11/22 Thanksgiving Holiday 16 11/27, 11/29 Simulation Project

Finalize Report

Multimedia 1:2

Choice of Simulator Software

• Aspen Plus

• Hysys

• Matlab

Multimedia 2:2

Contents

Navigation

Lecture 1 – Objectives

Be knowledgeable about the kinds of design decisions that challenge process design teams.

Have an appreciation of the key steps in carrying out a process design. This course, as the course text, is organized to teach how to implement these steps.

Be aware of the many kinds of environmental issues and safety considerations that are prevalent in the design of a new chemical process.

Understand that chemical engineers use a blend of hand calculations, spreadsheets, computer packages, and process simulators to design a process.

Lecture 1 – Outline

• Primitive Design Problems– Example

• Steps in Designing/Retrofitting Chemical Processes

– Assess Primitive Problem– Process Creation– Development of Base Case– Detailed Process Synthesis - Algorithmic Methods– Process Controllability Assessment– Detailed Design, Sizing, Cost Estimation,

Optimization– Construction, Start-up and Operation

• Environmental Protection• Safety Considerations

Primitive Design Problems

• The design or retrofit of chemical processes begins with a desire to produce profitable chemicals that satisfy societal needs in a wide range of areas:

• Partly due to the growing awareness of the public, many design projects involve the redesign, or retrofitting, of existing chemical processes to solve environmental problems and to adhere to stricter standards of safety.

– petrochemicals– petroleum

products– industrial gases– foods– pharmaceuticals

– polymers– coatings– electronic

materials– bio-chemicals

Origin of Design Problems

• Often, design problems result from the explorations of chemists, biochemists, and engineers in research labs to satisfy the desires of customers to obtain chemicals with improved properties for many applications.

• However, several well-known products, like Teflon (poly-tetrafluoroethylene), were discovered by accident.

• In other cases, an inexpensive source of a raw material(s) becomes available.

• Yet another source of design projects is the engineer himself, who often has a strong inclination that a new chemical or route to produce an existing chemical can be very profitable.

Steps in Product/Process Design

Initial Decision

Concept & Feasibility

Development & Manufacturing

Product Introduction


• Initial Decision


• Concept & Feasibility


• Development & Manufacturing


• Product Introduction

Steps in Process Design

Assess Primitive Problem

Detailed Process

Synthesis -Algorithmic

Methods

Development of Base-case

Plant-wide Controllability Assessment

Detailed Design, Equipment sizing,

Cap. Cost Estimation, Profitability Analysis,

Optimization


Part I• Assess Primitive Problem• Find Suitable Chemicals• Process Creation• Development of Base CasePart II• Detailed Process Synthesis

Part III• Detailed Design & Optimization

Part IV• Plantwide Controllability




Detailed Process


Methods




Optimization

PART I


• Process design begins with a primitive design problem that expresses the current situation and provides an opportunity to satisfy a societal need.

• The primitive problem is examined by a small design team, assessing possibilities, refining the problem statement, and generating more specific problems:

– Raw materials - available in-house, can be purchased or need to be manufactured?

– Scale of the process (based upon a preliminary assessment of the current production, projected market demand, and current and projected selling prices)

– Location for the plant

• Brainstorming to generate alternatives.

Example: VCM Manufacture

• To satisfy the need for an additional 800 MMlb/yr of VCM, the following plausible alternatives might be generated:

– Alternative 1. A competitor’s plant, which produces 2 MMM lb/yr of VCM and is located about 100 miles away, might be expanded to produce the required amount, which would be shipped. In this case, the design team projects the purchase price and designs storage facilities.

– Alternative 2. Purchase and ship, by pipeline from a nearby plant, chlorine from the electrolysis of NaCl solution. React the chlorine with ethylene to produce the monomer and HCl as a byproduct.

– Alternative 3. The company produces HCl as a byproduct in large quantities, thus HCl is normally available at low prices. Reactions of HCl with acetylene, or ethylene and oxygen, could produce 1,2-dichloroethane, an intermediate that can be cracked to produce vinyl chloride.

Survey Literature Sources

• SRI Design Reports• Encyclopedias

– Kirk-Othmer Encyclopedia of Chemical Technology– Ullman’s Encyclopedia of Industrial Chemistry– ...

• Handbooks and Reference Books– Perry’s Chemical Engineers Handbook– CRC Handbook of Chemistry and Physics– ...

• Indexes– See Auburn University Library

• Patents• Internet







Optimization

Detailed Process


Methods

PART II




Detailed Process


Methods



Optimization

PART III


Environmental Issues 1:2

• Handling of toxic wastes – 97% of hazardous waste generation by the chemicals and

nuclear industry is wastewater (1988 data).– In process design, it is essential that facilities be included

to remove pollutants from waste-water streams.

• Reaction pathways to reduce by-product toxicity – As the reaction operations are determined, the toxicity of

all of the chemicals, especially those recovered as byproducts, needs to be evaluated.

– Pathways involving large quantities of toxic chemicals should be replaced by alternatives, except under unusual circumstances.

• Reducing and reusing wastes– Environmental concerns place even greater emphasis on

recycling, not only for unreacted chemicals, but for product and by-product chemicals, as well. (i.e., production of segregated wastes - e.g., production of composite materials and polymers).

Environmental Issues 2:2

• Avoiding non-routine events– Reduce the likelihood of accidents and spills through the

reduction of transient phenomena, relying on operation at the nominal steady-state, with reliable controllers and fault-detection systems.

• Design objectives, constraints and optimization– Environmental goals often not well defined because

economic objective functions involve profitability measures, whereas the value of reduced pollution is often not easily quantified economically.

– Solutions: mixed objective function (“price of reduced pollution”), or express environmental goal as “soft” or “hard” constraints.

– Environmental regulations = constraints

Safety Issues

Compound LFL (%) UFL (%)

Acetylene 2.5 100

Cyclohexane 1.3 8

Ethylene 2.7 36

Gasoline 1.4 7.6

Hydrogen 4.0 75

Flammability Limits of Liquids and Gases LFL and UFL (vol %) in Air at 25 oC and 1 Atm

• These limits can be extended for mixtures, and for elevated temperatures and pressures.

• With this kind of information, the process designer makes sure that flammable mixtures do not exist in the process during startup, steady-state operation, or shut-down.

Design for Safety

• Techniques to Prevent Fires and Explosions– Inerting - addition of inert dilutant to reduce the fuel

concentration below the LFL– Installation of grounding devices and anti-static devices to

avoid the buildup of static electricity– Use of explosion proof equipment– Ensure ventilation - install sprinkler systems

• Relief Devices• Hazard Identification and Risk Assessment

– The plant is scrutinized to identify sources of accidents or hazards.

– Hazard and Operability (HAZOP) study is carried out, in which all of the possible paths to an accident are identified.

– When sufficient probability data are available, a fault tree is created and the probability of the occurrence for each potential accident computed.

Summary – The Design Process

• Steps in Designing and Retrofitting Chemical Processes

– Assess Primitive Problem – Covered Today (SSLW p. 1-31)

– Process Creation – Next Week (SSLW p. 77-94, 101-109)

– Development of Base Case– Detailed Process Synthesis - Algorithmic Methods– Process Controllability Assessment– Detailed Design, Sizing, Cost Estimation, Optimization– Construction, Start-up and Operation

• Environmental Protection– Environmental regulations = design constraints

• Safety Considerations– Should strive to design for “inherently safe plants”

Final Comments

• Capabilities upon Completion of this Class– How to simulate complete flowsheets and predict their

performance.– How to identify best achievable performance targets for a

process WITHOUT detailed calculations.– How to systematically enhance yield, maximize profit,

maximize resource conservation, reduce energy, and prevent pollution?

– How to debottleneck a process?– How to choose units and screen their performance?– How to understand the BIG picture of a process and use it

to optimize any plant?– And much more…..

Other Business

• Lab– Starts today in Ross 306– Aspen notes are available online and could be made

available for purchase at Engineering Duplicating Services if desired

– Headphones can be checked out with me or in the lab– Multimedia software is located under “Chemical

Engineering Apps”

• Next Lecture – August 28– Process Creation (SSLW p. 77-94, 101-109)

• Class Webpage– http://wp.auburn.edu/eden/?page_id=75

http://wp.auburn.edu/eden/?page_id=75

CHEN 4460 – Process Synthesis, Simulation and Optimization

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