Tutorial Modeling of monolith reactors

More documents

Recommendations

Info

The effectiveness factor Because the washcoat thickness is not explicitly modelled, the washcoat diffusion is incorporated using an effectiveness factor, defined as: η = Average reaction rate in washcoat Rate evaluated at surface conditions The effectiveness factor can be estimated from a submodel that usually involves solving a 1D diffusion-reaction problem. Washcoat geometry effects may be included. Hayes, et al Chemical Engineering Science, 62 2209-2215, 2007. Hayes, et al Chemical Engineering Science, 59 3169-3181, 2004. 50
Models for the converter • In reality the channels in the converter may not all have the same operating conditions. • The substrate constrains the velocity and concentrations to each channel, but heat transfer can occur among the channels. • A model <strong>of</strong> the entire converter may therefore be required. There are two general methods for modelling a converter: – Discrete models – Continuum models 51
Page 1 and 2: Introduction to Monolith Reactor Mo
Page 3 and 4: Why use computer modelling? • Exp
Page 5 and 6: Observations • The problem involv
Page 7 and 8: Model Scales Micro scale: At the at
Page 9 and 10: Mathematical formulation • The fu
Page 11 and 12: Basic models in common use • Sing
Page 13 and 14: The 3D SCM • The real monolith do
Page 15 and 16: The 2D approximate SCM • The 2D m
Page 17 and 18: The 2D SCM • All of the physical/
Page 19 and 20: Modelling the fluid domain Velocity
Page 21 and 22: Modelling the washcoat domain • T
Page 23 and 24: Diffusion in the washcoat • Diffu
Page 25 and 26: Modelling the substrate domain The
Page 27 and 28: Comparing 2D and 3D models • The
Page 29 and 30: Comparing 2D and 3D models • The
Page 31 and 32: Comparing 2D and 3D models Percenta
Page 33 and 34: Review of boundary layer flow Flow
Page 35 and 36: Boundary layers in a tube • At th
Page 37 and 38: Heat and mass transfer • Heat and
Page 39 and 40: 1D SCM mass balances The fluid phas
Page 41 and 42: 1D SCM energy balances The fluid ph
Page 43 and 44: Nusselt and Sherwood numbers • Fo
Page 45 and 46: Nusselt and Sherwood numbers • Ho
Page 47 and 48: Nusselt and Sherwood numbers • Ho
Page 49: Simplified 1D models • Dispersion
Page 53 and 54: Discrete converter models • A pas
Page 55 and 56: Momentum balance equation Velocity
Page 57 and 58: Energy balances The fluid phase ene
Page 59 and 60: Continuum model • In effect, the
Page 61 and 62: Model validation • All models mus
Page 63 and 64: Model validation - Example Heating
Page 65: Advertising supplement R.E. Hayes a

Tutorial Modeling of monolith reactors

Create successful ePaper yourself

Delete template?

Save as template?