Scale-up studies on electrically driven steam methane reforming

Abstract

This work is devoted to scale-up parametric studies of a new reactor for the steam reforming of methane driven by electrical current. The main distinguishing feature of this type of reactor is the use of direct electrical current flowing through metal particles to heat the whole reactor volume using Joule heating. The heat and mass transfer model uses six gaseous chemical species in the gas phase and inside the catalyst. Reaction rate expressions are taken from the literature (Langmuir–Hinshelwood–Hougen–Watson (LHHW) kinetics). In this work we consider a cylindrical electrically insulated tube with a diameter of 0.5 m and a height of 0.88 m, which is filled with metal particles and catalyst particles with diameters of 10 mm and 4 mm, respectively. Parametric runs have been carried out for different flow rates from 0.04 kg/s to 0.1 kg/s and electrical power from 185 kW to 462 kW. The results of simulations revealed that the cross-sectional temperature profile of a scaled-up reactor is mostly uniform, with small hot spots but a temperature difference that is usually within 100K. It was shown that the gas inflow located on the top gives smoother gradients of the particle temperature and gaseous species in comparison to the case when the gas is supplied from the bottom of the fixed bed.