Development of Sulfur Release and Reaction Model for Computational Fluid Dynamics Modeling in Sub-Bituminous Coal Combustion

Abstract

Pulverized coal-fired boilers applying low-NOx combustion technologies commonly suffer from high-temperature corrosion due to high-concentration H2S. Accurate prediction of sulfur species, especially H2S, is of great importance for the optimized design and operation of boilers and burners to reduce such problems. The sulfur release characteristics from coal and subsequent sulfur species gas-phase reaction mechanism are two critical steps controlling sulfur species evolution. In this study, first, a global sulfur species gas-phase reaction mechanism consisting of 10 reactions is proposed based on a detailed mechanism considering hundreds of elementary reactions. Kinetic parameters of the global mechanism are determined via a rigorous mathematical optimization process. Second, the sulfur release characteristics during coal pyrolysis and char burning of five kinds of sub-bituminous coals are investigated in a drop tube furnace (DTF). Equations describing the relationship between sulfur release and coal consu...