CHEN 4460 – Process Synthesis, Simulation and Optimization Dr. Mario Richard Eden Department 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
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CHEN 4460 – Process Synthesis, Simulation and Optimization
Class Overview & Introduction. CHEN 4460 – Process Synthesis, Simulation and Optimization Dr. Mario Richard Eden Department of Chemical Engineering Auburn University Lecture No. 1 – The Design Process August 21, 2012 Contains Material Developed by Dr. Daniel R. Lewin, Technion, Israel. - PowerPoint PPT Presentation
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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
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.
• 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
Steps in Product/Process Design
• Initial Decision
Steps in Product/Process Design
• Concept & Feasibility
Steps in Product/Process Design
• Development & Manufacturing
Steps in Product/Process Design
• 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
Steps in Process Design
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
Steps in Process Design
Assess Primitive Problem
Development of Base-case
Detailed Process
Synthesis -Algorithmic
Methods
Plant-wide Controllability Assessment
Detailed Design, Equipment sizing,
Cap. Cost Estimation, Profitability Analysis,
Optimization
PART I
Steps in Process Design
Steps in Process Design
Assess Primitive Problem
• 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
Steps in Process Design
Assess Primitive Problem
Development of Base-case
Plant-wide Controllability Assessment
Detailed Design, Equipment sizing,
Cap. Cost Estimation, Profitability Analysis,
Optimization
Detailed Process
Synthesis -Algorithmic
Methods
PART II
Steps in Process Design
Steps in Process Design
Assess Primitive Problem
Development of Base-case
Detailed Process
Synthesis -Algorithmic
Methods
Detailed Design, Equipment sizing,
Cap. Cost Estimation, Profitability Analysis,
Optimization
PART III
Plant-wide Controllability Assessment
Steps in Process Design
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