Cancellation of heat effects in catalytic distillation

✍ Scribed by Veikko J Pohjola; Juha Tanskanen

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 278 KB
• Volume: 79
• Category: Article
• ISSN: 1385-8947
• DOI: 10.1016/s1385-8947(00)00163-7

✦ Synopsis

Heat effects in distillation, especially those caused by unequal heats of vaporization of components and highly nonadiabatic operation, were shown in earlier papers to cancel favorably in binary distillation when measuring and computing composition profiles along column height. We show here that the same favorable cancellation takes place in multicomponent catalytic distillation where heat effects are caused by a release or consumption of heat of reaction. A generic profile in terms of pseudo-composition of vapor, solved analytically by applying the linearized theory of multicomponent mass transfer, is given for exothermic reactions as a function of two dimensionless parameters, an eigenvalue of the number of mass transfer units matrix and an eigenvalue of the mass transfer rate factor matrix. Comparison with the solution that ignores the heat effects completely is made in terms of both pseudo-composition and actual composition. The final conclusion of the study is that nonequimolarity can be safely ignored in most practical cases of multicomponent catalytic distillation when computing bulk compositions on a plate in the reaction zone of a column.