Kinetic Reactor Design Lecture Note 1-1

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Lecture 1-1. Lecture Notes from Univerisit Teknologi PETRONAS.The main reference used is Essentials of Chemical Engineering published by Prentice Hall.

Text of Kinetic Reactor Design Lecture Note 1-1

  • CCB 3043

    Kinetics and Reactor

    Design

    Associate Professor Dr Ku Zilati Ku Shaari

    May 2014

  • CHAPTER 1

    Course Outline

  • CHAPTER 1

    Course Learning Outcomes (CO)

    1. Explain the fundamentals of different types of reactors and

    reactor operations.

    2. Apply the principles of chemical reaction engineering in

    solving reaction engineering problems, both for homogeneous

    and heterogeneous systems.

    3. Interpret and analyze reaction kinetics and reactor systems for

    optimum reactor performance.

    4. Apply reactor design equations for a broad range of conditions

    including multiple reactions, catalytic reactions and non-

    isothermal processes.

    Apply knowledge of mathematics, science and engineering fundamentals and an engineering specialization to the solution of complex chemical

    engineering problems.

    Identify, formulate, research literature and analyse complex chemical engineering problems reaching substantiated conclusions using first

    principles of mathematics, natural sciences and engineering sciences

    Program Outcomes (PO)

  • CHAPTER 1

    Chemical Engineering Program Outcomes (PO)

    1. Apply knowledge of mathematics, science and engineering fundamentals and an engineering

    specialization to the solution of complex chemical engineering problems.

    2. Identify, formulate, research literature and analyse complex chemical engineering problems

    reaching substantiated conclusions using first principles of mathematics, natural sciences

    and engineering sciences

    3. Design solutions for complex chemical engineering problems and design systems,

    components or processes that meet specified needs with appropriate consideration for

    public health and safety, cultural, societal, and environmental considerations.

    4. Investigate complex chemical engineering problems using research based knowledge and research

    methods including design of experiments, analysis and interpretation of data and synthesis of

    information to provide valid conclusions.

    5. Use modern engineering and IT tools to evaluate complex chemical engineering activities.

    6. Apply reasoning informed by contextual knowledge to assess societal, health, safety, legal and

    cultural issues and the consequent responsibilities relevant to professional engineering practice.

    7. Understand the impact of professional engineering solutions in societal and environmental contexts

    and demonstrate knowledge of and need for sustainable development.

    8. Apply ethical principles and commit to professional ethics and responsibilities and norms of

    chemical engineering practice

    9. Communicate effectively on complex chemical engineering activities with the engineering

    community and society.

    10. Function effectively as an individual, and as a member or leader in diverse teams and in multi-

    disciplinary settings.

    11. Recognise the need for, and have the preparation and ability to engage in independent and life-long

    learning in the broadest context of technological change.

    12. Demonstrate knowledge and understanding of engineering and management principles and apply

    these to ones own work, as a member and leader in a team, to manage projects and in multidisciplinary environments.

  • CHAPTER 1

    Important Rules and Regulations

    1. PUNCTUAL!!! I am very strict about you

    BEING ON TIME!

    2. No make-up Test or Quiz (unless with

    MC, UTP event approval form or death

    certificate of immediate family

    3. Attendance is compulsory, only 3

    absences is accepted

  • CHAPTER 1: Mole

    Balances

    Lecture 1

  • CHAPTER 1

    Objectives- Chapter 1:

    Define the rate of chemical reaction.

    Distinguish the difference in operation of different types of reactor

    Apply the mole balance equations to a batch reactor, CSTR, PFR, and PBR.

  • CHAPTER 1

    Topics (Chapter 1):

    Lecture 1:

    Chemical Identity

    Reaction Rate

    Lecture 2:

    General Mole Balance Equation

    Mole Balance for Different Reactor

    Types

    Lecture 3: Mole Balance for Different Reactor

    Types

    Examples

  • CHAPTER 1

    WHY CHEMICAL ENGINEERS NEED TO

    STUDY REACTION ENGINEERING?

  • CHAPTER 1

    CHEMICAL

    REACTION

    ENGINEERING

    CHEMICAL REACTION REACTOR DESIGN

  • CHAPTER 1

    Basic knowledge:

    Very important

    Applications:

  • CHAPTER 1

    Application of Chem Rxn Engr

    (please read page 1-3)

    Manufacture of polyethylene and ethylene.

    Plant Safety (Nitroanaline Plant Explosion Exothermic Reactions That Run Away).

    Oil recovery.

    Lubricant Design (Effective Lubricant Design Scavenging Free Radicals).

    Enzyme kinetics and Pharmacokinetics.

    Cobra Bites (Pharmacokinetics of Cobra Bites Multiple Reactions in a Batch Reactor (body).

  • CHAPTER 1

    Reaction rate, -rA

    What does it tell???

    How fast a number of moles of one

    chemical species are being

    consumed to form another chemical

    species (identity).

  • CHAPTER 1

    Chemical Identity

    Identity of a chemical species is

    determined by the kind, number and

    configuration of the species atom

    C C

    H H

    CH3 CH3

    Cis-2-butene

    C C

    H

    H CH3

    CH3

    Trans-2-butene

    Considered as 2 different species due to the different configuration even when

    the numbers of atoms of elements are the same

  • CHAPTER 1

    Chemical Identity

    A reaction is said to occur when a

    species lost its identity and assumed a

    new form either by:

    Change in the number of atoms in the

    compound

    Change in structure of the compound

    Change in configuration of atoms

  • CHAPTER 1

    3 ways of losing chemical identity:

    Decomposition

    Combination

    Isomerisation

    Chemical Identity

    22233 CHCHHCHCH

    NO2ON 22

    232252

    CHCCHCHCHHC

  • CHAPTER 1

    Reaction rate

    Defined as the rate at which a chemical

    species reacts (or formed) per unit volume

    Expressed as:

    Rate of reactant disappearance

    Rate of product formation

  • CHAPTER 1

    Example:

    A B

    Rate of reaction is given by:

    -rA = rate of disappearance of A

    rB = rate of formation of B

    For heterogeneous reaction, rate of reaction is

    express in terms of catalyst volume or catalyst weight

    Reaction rate

  • CHAPTER 1

    Reaction rate is an intensive properties depends on concentration, temperature,

    pressure, or type of catalyst, present in a

    system

    Reaction rate is NOT influence by type of

    reactor used!!

    Reaction rate is expressed as:

    -rA = kCAn

    NOTE: dCA/dt is not the definition for reaction rate

    Reaction rate

  • CHAPTER 1

    Reaction rate:

    Example: Is NaOH

    reacting?

    CSTR - operated at steady state; inlet flow rate = outlet flow rate

    Perfectly well mixed system; concentration of samples taken at 10 a.m is the same as concentration taken at 5 p.m

    Therefore: dCA/dt = 0

    Does this mean that -rA = 0; i.e. no reaction occurs?

    The answer is NO!

    dt

    dCr AA

  • CHAPTER 1

    For any species A:

    rA is the rate of formation of species A per unit

    volume [e.g. mol/dm3.s]

    rA is a function of concentration, temperature,

    pressure, and the type of catalyst (if any)

    rA is independent of the type of reactor (batch,

    plug flow, etc.)

    rA is an algebraic equation, not a differential

    equation

    Reaction rate

  • CHAPTER 1

    Types of Reactor:

    1. Batch reactor

    2. Continuous-Stirred Tank Reactor

    (CSTR)

    3. Plug Flow Reactor (PFR) or

    Turbular Reactor

    4. Packed Bed Reactor (PBR)

  • CHAPTER 1

    Industrial reactors

    Types of reaction

    Liquid phase reaction Gas phase reaction

    Semi batch reactor,

    CSTR

    Tubular reactor

  • CHAPTER 1

    Different types of reactor: 1) Batch reactor

    Physical shape: Tank

    Used for: small scale operation

    process that is not suitable for continuous operation.

    Advantage: High conversion longer residence time

    Disadvantage High cost

    Product variability

    Not for large-scale operation

  • CHAPTER 1

    Different types of reactor: 2) Continuous-Stirred Tank Reactor (CSTR)

    Physical shape: Tank

    Continuous Flow, Steady state, Perfectly mixed

    Used for: Liquid phase reaction

    process that is suitable for continuous operation.

    Advantage: Continuous operation

    Disadvantage Not for non-ideal mixing

  • CHAPTER 1

    Different types of reactor: 3) Plug Flow Reactor (PFR)

    Physical shape: Cylindrical pipe

    Continuous Flow, Steady state, Perfectly mixed

    Used for:

    Gas phase reaction

    Reaction rate varies axially NOT radially.

    Reactant Product

  • CHAPTER 1

    Different types of reactor: 4) Packed Bed Reactor (PBR)

    Physical shape: Cylindrical

    Continuous Flow, Steady state, Perfectly

    mixed

    Used for:

    Fluid-solid heterogeneous react

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