Short-Channel Structured Reactor as a Catalytic Afterburner

P Jodłowski,J Ochońska,A Knapik,M Iwaniszyn,A Gancarczyk,A Kołodziej,E Janowska-Renkas,J Łojewska

doi:10.1007/s11244-013-9966-8

Abstract

Short-channel structures of triangular and sinusoidal channel cross-sectional shape were examined experimentally to find their heat (or mass) transfer and flow friction (flow resistance) characteristics. A particular emphasis was placed on influence of the channels length (referred to its hydraulic diameter) on transport and hydrodynamic characteristics. The transport and friction properties were correlated in terms of dimensionless channel length with satisfactory accuracy. The dimensionless channel length was proved to be a key factor that determines the transport and friction coefficients. Comparison with ceramic monolith has shown possibility of using the structures in automotive catalytic converters.

Highlights

During last decades, structured reactors—mainly classic monoliths—have achieved remarkable success, mainly dueTop Catal (2013) 56:273–278 to their application as automotive converters
In spite of amazingly low flow resistance, their further utilization is limited by insufficient heat and mass transfer
Due to sustained progress in designing more and more active catalysts and resulting from that enhanced kinetics of catalytic reactions, mass transfer to the catalyst becomes a limiting factor leading to excessive reactor length and unnecessary consumption of precious catalyst

Summary

Introduction

During last decades, structured reactors—mainly classic monoliths—have achieved remarkable success, mainly due. In spite of amazingly low flow resistance, their further utilization is limited by insufficient heat and mass transfer. Near to the channel inlet, in the entrance (or mixing) section, a so-called developing laminar flow leads to highly enhanced heat and mass transport; which simultaneously gives rise to undesirable increase in flow resistance. A promising way to intensify a process can be to ‘‘cut’’ monolith to force developing laminar flow in a major part of the channel. Such an idea was proposed recently by Kołodziej et al [1–3]. Heat transfer and flow resistances were studied for short-channel structures of triangular and sinusoidal cross-sectional shape within large range of Reynolds numbers. This study follows the approach and nomenclature in our previous papers [1–3] following Shah and London [4]

Experimental

Flow Resistance

Re D þ

Heat and Mass Transfer

Comparison with Monolith and Packed Bed

Conclusions