Thiele Modulus

Graavfsna
timer Asked: Dec 8th, 2015

Question Description

Thiele Modulus

Unformatted Attachment Preview

Problem 1. Thiele Modulus In class, we derived the relationship between the effectiveness factor and a Thiele Modulus for a first-order reaction. Repeat the calculation for a zero-order reaction occurring in a catalyst particle with slab geometry. For a zero-order reaction, the rate is constant as long as the concentration is greater than zero; however, the rate must be equal to zero when the concentration becomes zero. You cannot allow the concentration to become negative. As in class, assume that the thickness of the slab is 2L and that the height and width of the slab are large in comparison (i.e. Diffusion will be in one direction only). Assume that external mass transfer limitations are negligible and define your "x-axis" from the center of the slab. a) Write the differential equation for the material balance in a differential volume within the slab. Make the equation dimensionless and define a Thiele Modulus. (Hint: Is it necessary to define a dimensionless concentration?) b) Write the boundary condition for this equation at x =L, the outside surface of the slab. Do not try to write a boundary condition for x = 0. c) You can now solve for C(x), leaving one integration constant undetermined. Depending on the value of this constant, the concentration at the center, CO), will either be positive or negative. Obviously, C(0) cannot be negative. Plot the actual concentration profiles for these two cases. d) Determine the actual reaction rate in the slab as a function of the Thiele Modulus. e) Define an effectiveness factor and determine how it varies with the Thiele Modulus.
User generated content is uploaded by users for the purposes of learning and should be used following Studypool's honor code & terms of service.

This question has not been answered.

Create a free account to get help with this and any other question!

Related Tags

Brown University





1271 Tutors

California Institute of Technology




2131 Tutors

Carnegie Mellon University




982 Tutors

Columbia University





1256 Tutors

Dartmouth University





2113 Tutors

Emory University





2279 Tutors

Harvard University





599 Tutors

Massachusetts Institute of Technology



2319 Tutors

New York University





1645 Tutors

Notre Dam University





1911 Tutors

Oklahoma University





2122 Tutors

Pennsylvania State University





932 Tutors

Princeton University





1211 Tutors

Stanford University





983 Tutors

University of California





1282 Tutors

Oxford University





123 Tutors

Yale University





2325 Tutors