A new acid gas destruction kinetic model for reaction furnace of an industrial sulfur recovery unit: A CFD study

Abstract

• Developing a reduced reaction mechanism for acid gas combustion. • Simulating detailed full-scale reaction furnace with new reduced kinetic model. • Predicting accurate results in terms of temperature profile and chemical species. • Vectorwall and co-directional diffuser showed the lowest radiative heat flux. • Common checkerwall and co-directional diffuser showed the highest H2S efficiency. A new reduced kinetic model is developed for the simulation of acid gas destruction in the industrial reaction furnace of sulfur recovery units. The proposed CFD model includes the reactions of the new kinetic mechanism, steady laminar flamelet model, and fine details of industrial furnace geometry related to the burner, choke ring, checkerwall, and exhaust pipe holder. The mean relative error in predicting H 2 S conversion using CFD, coupled with our new kinetic model, is about 9.48% when compared with the industrial data. The influences of two types of burners and the checkerwalls on the thermohydrodynamics behaviors of the reaction furnace are investigated. The reactor equipped with Vectorwall and co-directional diffuser shows the lowest radiative heat flux (RHF) and favorable outlet temperature to protect the tube sheets, while the one with conventional checkerwall and co-directional diffuser shows the highest H 2 S conversion efficiency in the furnace.