DOC modeling combining kinetics and mass transfer using inert washcoat layers

Modelling of Mass Transfer Resistances in Non-uniformly Washcoated Monolith Reactors

“…Then, a mass transfer coefficient is developed through an effective diffusivity coefficient. Just like the 1D models using an effectiveness factor, the 1+1D mode can capture internal diffusion limitations-however, to the best of our knowledge, all of these axially and radially resolved models assume the washcoat to be a flat slab with uniform properties [5,[18][19][20][21][22]. Hence, they fail to capture differences in diffusion resistance that arise from tangential washcoat maldistributions-which could vary as much as 10 μm along the side to about 150 μm in the corners of the channel [23].…”

“…In this paper, we present a novel modelling framework; combining the 1+1D DOC model developed by Lundberg et al [18,19] with a sectionalizing method similar to Papadias et al [16]-in order to allow for an arbitrary washcoat geometry with local washcoat features such as cracks. Intelligent gravimetric analysis (IGA) and scanning electron microscopy (SEM) are used to calculate local effective diffusivities.…”

Multiscale reactor modelling of total pressure effects on complete methane oxidation over Pd/Al2O3

“…33 However, the Knudsen diffusion is dependent on the porous material and has been discussed, from theoretical and experimental perspectives, to exhibit a relatively low significance on the effective diffusion. [34][35][36][37][38][39][40] The molecular diffusion has a dominant effect on the effective diffusivity in a mesoporous structure, while in a microporous structure, the Knudsen diffusion should be considered for a correct estimate of the effective diffusion coefficient. In the present study, the porous structure is assumed to populate meso-and macro-pores, and Knudsen diffusion is hence omitted from the Bosanquet correlation.…”

Efficient Experimental Approach to Evaluate Mass Transfer Limitations for Monolithic DOCs

“…For diesel engines, the diesel oxidation catalyst (DOC) is a vital part of the exhaust aftertreatment system (EATS) since its performance very much affects the downstream components' performance. Hence, gaining insight into the DOC operation is of utmost interest [2]. For efficient heterogeneous catalyst design, large active surface area is key.…”