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Politecnico di Torino | |||||||||||||||||
Academic Year 2012/13 | |||||||||||||||||
01NFFMB Reactors and chemical kinetics |
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1st degree and Bachelor-level of the Bologna process in Chemical And Food Engineering - Torino |
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Subject fundamentals
The aim of the course is to provide the basic tools for the design and the operation of chemical reators. The main types of homogeneous reactors are presented and their performance (conversion, yield and selectivity) are expressed as functions of the operating conditions. The concepts of risk, danger and chemical risk are defined. The relation between hazardous properties of the substances (toxicity, flammability, etc.) and the dangers arising from their use are examined.
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Expected learning outcomes
Kinetics of homogeneous, enzymatic and microbiological chemical processes ;
Mass and energy conservation principles in reactive systems; Non ideal flow models for continuous reactors and residence time distribution Application of model equations to the design of reactors and to kinetic investigation. Skills to be achieved Reactor choice and identification of the optimal operating conditions on the basis of the chemical process features; |
Prerequisites / Assumed knowledge
Good knowledges in the fields of thermodynamics and transport phenomena.
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Contents
Ideal chemical reactors: perfectly mixed batch reactor: conversion vs. time in isothermal conditions, optimal productivity, adiabatic temperature rise, conversion and temperature vs. time; PFR: local mass balance, conversion in isothermal systems, local energy balance, axial profiles of conversion and temperature in adiabatic and non-adiabatic systems; CSTR: conversion in steady state, stability and multiplicity.
Hybrid systems: tubular reactor with recycled flow, cascade of CSTRs. Continuous reactors with non-ideal fluid dynamics: models for tubular reactors: axial dispersion, bidimensional model; models for mixed reactors: stagnant zones, by-pass, two-parameter models; residence times distribution: distribution functions, tracers, parameter estimation, micro and macro.fluids; Selectivity and yield in chemical reactors with multiple reactions: parallel and consecutive reactions, optimal operating conditions. Temperature optimisation for reversible exothermic processes: optimala and equilibrium temperatures, tubular reactors with intercoolers. Run-away in chemical reactors: run-away phenomenology, MTSR and TMR, run-awayreactions, risk classification. Reactors for enzymatic processes: Michaelis-Menten kinetic, kinetic constants estimate, influence of operating conditions (temperature and pH), enzymatic processes in continuous and batch reactors, competitive and non-competitive inhibition phenomena. Reactors for microbiological processes (6 hours): Monod kinetics, stoichiometry and mass balance, biomass growth in batch and continuous reactors, kinetic constants estimate, operative plots, biomass washout in a CSTR, product inhibition. |
Texts, readings, handouts and other learning resources
Handouts are available on the web page of the course.
Textbooks: K. .R. Westerterp et al., Chemical reactors design and operation, Wiley O. Levenspiel, Chemical Reaction Engineering, Wiley H. S Fogler, Elements of Chemical Reaction Engineering, Prentice Hall |
Assessment and grading criteria
The exam consists of two written tests.
The first test lasts 45 minutes and includes a large set of theoretical questions about the course program; for some questions predetermined responses are proposed, others require brief demonstrations or the representation of data & principles in graphic form. The second test lasts one hour and 45 minutes and involves the resolution of stoichiometric balanceS in open and closed systems, design and optimization of chemical reactors. During both written tests, students can only consult the material provided by the teacher; no other sources of information such as books, manuals, or notes are allowed. The final vote is the arithmetic average of the votes obtained in the two tests. |
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