Using COMSOL for Chemical Reaction Engineering Your name COMSOL

Overview COMSOL in two minutes The COMSOL product line Modeling in reaction engineering Reaction Engineering Lab COMSOL Multiphysics Example studies –Heterogeneous catalysis –Homogeneous catalysis Concluding remarks

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The COMSOL product line COMSOL Multiphysics COMSOL Script Acoustics Module Chemical Engineering Module Structural Mechanics Module Earth Science Module Heat Transfer Module MEMS Module RF Module Reaction Engineering Lab Signals and Systems Lab Optimization Lab CAD Import Module Material Library AC/DC Module

Reaction Engineering Understanding the influence of chemical reactions in a process … … and using that knowledge to achieve goals in development and design Covers a broad range of applications… on widely different scales

Modeling in Reaction Engineering Modeling is a natural part of developing and optimizing chemical processes Enters at all levels –Modeling the chemical reactions –Calibrating the reaction model with experimental data –Optimizing the chemical process in ideal reactors –Exploring design in detailed reactor geometries

Reactor Models Space and time-dependent tank reactor

Ideal tank reactors are perfectly mixed Reactor Models

Ideal tank reactors are perfectly mixed Reactor Models

Space and time-dependent flow reactor

Reactor Models Ideal tubular reactors are at steady-state

Reactor Models Ideal tubular reactors are at steady-state

Ideal reactors –Well established concept –Often adequate –Computationally cheap Space-dependent reactors –Detailed reactor information, e.g. Temperature distribution The effect of recirculation zones Detailed mass transport in concentrated mixtures …etc –Computationally demanding Ideal or space-dependent models?

Screen and evaluate reaction sets Calibrate the chemistry with experimental data Optimizing the chemical process in ideal reactors Transfer the kinetic model and physical properties of the reacting mixture from ideal reactors to space-dependent systems Reaction Engineering Lab

Chemical Reactions Screen reaction sets

Calibrate the chemical model with experimental data k 1 = [s -1 ] k 2 = [s -1 ] k 3 = [s -1 ] Chemical Reactions rate constants

Ideal Reactor Models Ideal tank reactors –Batch reactor –Semibatch reactor –CSTR Ideal tubular reactors –Plug-flow reactor

Perform reactor analysis and design Ideal Reactor Models

Transfer the kinetic model and physical properties of the reacting mixture from ideal reactors to space-dependent systems Move into detailed reactor analysis and design Space-dependent Models

COMSOL Multiphysics Set up and solve time and space-dependent models Build your model by combining application modes –Fluid flow –Mass transport –Energy transport –… Structural mechanics –… Electromagnetics Explore and optimize chemical processes in detailed reactor geometries

Chemical Engineering Module Fluid flow application modes –Laminar flow –Turbulent flow –Flow in porous media –Non-Newtonian flow –Compressible flow –Two-phase flow

Mass transport application modes –Diffusion –Convection and Diffusion –Multi-component transport –Ionic migration Energy transport application modes –Conduction –Convection and conduction –Radiation Chemical Engineering Module

NOx reduction in a catalytic converter Selective reduction of NO by NH 3 Honeycomb monolith with V 2 O 5 /TiO 2 catalyst Plug-flow model Space-dependent model Image courtesy of ArvinMeritor

NOx reduction in a catalytic converter Competing reactions –NO reduction by NH 3 –NH 3 oxidation Eley-Rideal kinetics Plug-flow model of a channel

Reaction Engineering Lab

A cylindrical monolith channel Free flow in the center coupled to porous media flow in the catalytic wash-coat Reactions occur in the porous wash-coat Space-dependent model catalytic wash-coat channel inlet 0.36 m

COMSOL Multiphysics

Homogeneous catalysis in a bubble column Ibuprofen synthesis Bubble column reactor with organometallic Pd catalyst in the liquid phase Ideal batch reactor model Space-dependent two- phase model

Ibuprofen synthesis Homogeneous catalysis –PdCl 2 (PPh 3 ) Carbonylation reaction –CO gas dissolves in the reacting phase

Reaction Engineering Lab

Bubble column Two-phase flow Gas bubbles drive the flow –1 mm bubbles –Volume fraction of gas; 0,005, 0,001, 0,05 Reactions occur in the liquid phase Space-dependent model

COMSOL Multiphysics

Liquid flow as function of volume fraction of gas Vf = Vf = Vf = 0.05

Dissolution of CO gas in liquid Vf = 0.005

Vf = 0.01 Dissolution of CO gas in liquid

Vf = 0.05 Dissolution of CO gas in liquid

Concluding remarks Reaction Engineering Lab –Explore chemical models –Calibrate with respect to experiments –Ideal reactor modeling COMSOL Multiphysics –Space and time-dependent reactors –Flow, mass and energy transport –Arbitrary physics couplings