Chemical Kinetics Simulation of High Temperature Hydrocarbons Reforming in a Solar Reactor

Abstract

This study is aimed at developing a simulation model of a solar Volumetric reactor for hydrocarbon reforming, operating at high temperature and pressure. It will then be used to optimize the reactor design and analyze its performance. The model development utilizes previous and on-going experimental work on Volumetric receiver and catalyst development. The reaction’s kinetics are computed, using the CHEMKIN II simulation package. The chemical kinetic modeling of the relevant C-H-O system is based on: (i) Definition of the relevant computation domain and parameters: temperature, pressure, reactant compositions, residence time, and catalyst load, (ii) Utilizing laboratory measurements at 700–1400K and 1–4 bar. to quantify the kinetic parameters for both, H2O, and CO2 reforming of CH4 and for the Reverse Water Shift reaction. Calculated and measured data are compared for three representative cases, showing a good agreement. The results indicate that the Arrhenius method can be a viable and practical way to predict the behavior of steam and CO2 reforming over a range of temperatures and pressures. Furthermore, it is shown that the present approach can provide a method for estimating the desirable dimensions of the reactor for reforming of CH4. Additional, on-going computational and experimental work, which would provide a more accurate simulation, can easily be implemented using the present numerical model.

A review of solar methane reforming systems

“…Moreover, instead of modeling each individual pin, an average medium approach was used where the effective distributed volumetric optical properties, flow resistance, and convec- Figure 25: Schematic of DIAPR computational model domain [67] tive heat transfer were assigned to each computational cell (control volume) within the porcupine absorber domain. The kinetic mechanism for the steam reforming was modeled using two global reactions calibrated to fit experimental results [68]. Parametric studies show that the pin length was very important in terms of ensuring contact between the gas flow and catalyst.…”