Download presentation

Presentation is loading. Please wait.

Published byBrooks Nordan Modified over 2 years ago

1
Shrinking Core: Non-Isothermal Quak Foo Lee Chemical and Biological Engineering The University of British Columbia

2
Shrinking Core: Non- Isothermal Heat generated at reaction front, not throughout the volume In Steady State, Solve R r rcrc TsTs TfTf TcTc

3
T Conditions

4
Boundary Condition 1: r = r c Heat is generated = Heat conducted out through product layer Area

5
Boundary Condition 2: r = R Heat arriving by conduction = Heat removed for from within particle convection Bi -1 Can be obtained from B.C. 1

6
Solution Combine equations and eliminate T S to get T c -T f

7
Recall from Isothermal SC Model Substitute C A,c into (T c –T f ) equation

8
T c - T f ConductionConvection Diffusion in Product Layer Reaction Mass Transfer

9
Can Heat Transfer Control the Rate in Endo- and Exothermal Rxn? Consider C A,c ≈ C A,f ; initially rapid reaction a) Endothermic with poor heat transfer, heat will be consumed in reaction, and if can’t transfer heat in, T C will drop reaction rate ↓ markedly and rate of reaction become the slow step occurring at a rate dictated by the flow of heat. b) Exothermic initial rapid reaction and with poor Q, T C will increased, then rate of reaction ↑ and eventually reach point where gaseous reactant can’t be transferred fast enough (external mass transfer or diffusion). Hence rate is limited.

Similar presentations

OK

Chemical Reactions & Equations Dr. Ron Rusay Energy Thermodynamics Crash Course: https://www.youtube.com/watch?v=RfzYl7Ll5Ug.

Chemical Reactions & Equations Dr. Ron Rusay Energy Thermodynamics Crash Course: https://www.youtube.com/watch?v=RfzYl7Ll5Ug.

© 2018 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Download ppt on respiration in humans Download ppt on automatic street light control Ppt on endangered species Ppt on regional trade agreements japan Ppt on agriculture insurance in india Ppt on world population day 2013 Topics for ppt on environmental science Ppt on principles of object-oriented programming examples Ppt on review of related literature sample Module architecture view ppt on ipad