Simulation and Optimization of Homogeneous Decomposition of Sulfur Trioxide Gas on a Catalytic Surface
This paper deals with the development of a two-dimensional numerical model to predict the wall-catalyzed homogeneous decomposition of sulfur trioxide in a tubular component geometry for the production of hydrogen by the sulfur-iodine thermochemical water splitting cycle, a candidate cycle in the U.S. Department of Energy Nuclear Hydrogen Initiative. The reacting fluid is a mixture of sulfur trioxide gas and water vapor inside the tubes of a heat exchanger. The heat exchanger is made of Incoloy alloy 800H with ALFA-4 coated on the inner walls which acts as a catalyst. Decomposition of sulfur trioxide depends on many different parameters such as wall surface temperature, mole flow rate of the reacting mixture, diameter of the reactor tube, length of the reactor tube, operating pressure and inlet temperature of the reacting mixture. The effects of wall surface temperature, diameter of the reactor tube and mole flow rate on the decomposition of sulfur trioxide were investigated using a two-dimensional numerical model using Computational Fluid Dynamics (CFD) techniques. The preprocessor GAMBIT was used to create a computational mesh and the CFD software package FLUENT 6.2.16 [1] which is based on finite volume methods was used to simulate the problem. Both FLUENT 6.2.16 and Tecplot 10.0 are used to post process the problem.