FEM-based modeling of a calorimetric gas sensor for hydrogen peroxide monitoring

Abstract

A physically coupled finite element method (FEM) model is developed to study the response behavior of a calorimetric gas sensor. The modeled sensor serves as a monitoring device of the concentration of gaseous hydrogen peroxide (H 2 O 2 ) in a high temperature mixture stream in aseptic sterilization processes. The principle of operation of a calorimetric H 2 O 2 sensor is analyzed and the results of the numerical model have been validated by using previously published sensor experiments. The deviation in the results between the FEM model and experimental data are presented and discussed.

Advancements in Microfabricated Gas Sensors and Microanalytical Tools for the Sensitive and Selective Detection of Odors

“…Calorimetric devices normally employ two thermosensitive components, which convert enthalpy-changes at the surface of the sensor into an electric signal [ 111 ]. These components are generally deployed in the form of beads or using a metal-meander structure on top of a silicon-based substrate [ 112 ]. One of thermosensitive components is generally made active with a catalytic material coated on its surface, whereas the other remains inactive and it is set as reference.…”

“…It consists of two Pt-meander structures: one passive and the other catalytically activated by a MnO 2 layer. Reprinted with permission from ref [ 112 ]. Copyright 2017, Wiley-VCH GmbH.…”

Thermocatalytic Behavior of Manganese (IV) Oxide as Nanoporous Material on the Dissociation of a Gas Mixture Containing Hydrogen Peroxide

“…For this purpose, the ratio of pores (see Figure 6 ) in the bulk catalyst is assumed to be similar to the ratio of voids between MnO particles on the catalyst surface. In this context, a first hand approximation to analyze a H O sensor structure subjected to a perpendicular flow of gaseous H O , as for conventional sensor measurement [ 28 ]. Thereby, the values of and through the catalyst structure are the previously derived values in the case of parallel flow direction (presented in Section 3.1 ).…”

“…In Equation ( 11 ), D is the binary diffusion coefficient of H O , determined for the current H O containing gas by applying the Chapman-Enskog theory; for justification and detailed derivation we refer to ref. [ 28 ]. The variable represents the velocity in m/s, c is the concentration of H O in the flow in mol/m , and k is the reaction rate in 1/s.…”

“…While the auto-thermal decomposition of H O (described in literature as homogeneous decomposition) dominantly occurs at temperatures above 400 C [ 24 , 25 ], catalysts can be used to lower the activation energy of the decomposition process [ 26 ]. Hence, H O decomposition reaction can occur at any temperature (described in literature as heterogeneous decomposition) and about 105 kJ/mol is released [ 25 , 27 , 28 ].…”