Mathematical modeling of structured reactors, particularly monoliths, can help reduce experimental efforts during process development. These models for monolith reactors are represented in various space-time scales and pose a multiscale modeling problem. The modeling strategies available for monoliths can be categorized into single-channel models(SCM) and entire converter models(ECM). Most of the numerical analyses have fixated on the behavior of a single channel in the monolith reactor, which implicitly assumes that all channels behave identically. The above assumption does not hold for the reactors with significant heat losses and non-uniform flow distribution. Due to the computational limitations, monoliths are modeled as a continuum in full-scale catalytic reactors models without any rigorous evaluation of the effective properties and reaction rates. The accuracy of these models reduces significantly when the properties of the solid and fluid phases differ by a large magnitude or the Damkohler number associated with the heterogeneous reactions is large. The present work focuses on developing a modeling strategy to render the original multiphase reactor as a single phase. We aim to reduce the computational expenses of full-scale multichannel reactor simulations while maintaining the system's accuracy.