Performance Modeling and Analysis of H2O2 Catalytic Pellet Reactors

Abstract

The present paper describes a steady 1D model of the hydrogen peroxide (HP) decomposition flow in a pellet-type catalytic bed and its application to the parametric design of a typical reactor for small rocket propellant thrusters. The two-phase liquid-gas-vapor flow through the bed is treated as an homogeneous, adiabatic, chemically reacting flow, whose properties depend on the local composition. Fast equilibrium HP adsorption and firstorder finite-rate desorption is assumed for the one-step HP decomposition reaction on the catalyst surface. Standard viscous/aerodynamic correlations for porous media are used to account for pressure losses. The predictions of the model depend on a limited number of uncertain parameters, whose values can be readily determined by comparison with the available experimental data. Good agreement has been attained between the model predictions and the results of HP monopropellant thruster firings in Alta’s Green Propellant Rocket Test Facility. The model provides a rational framework for identifying the main operational parameters of catalytic pellet beds, understanding their interactions, and efficiently guiding the reactor sizing and design, using the indications easily obtained from sensitivity analyses.