Kinetic study of the continuous removal of SO_x using polyacrylonitrile-based activated carbon fibres: 2. Kinetic model

Sulfur dioxide was continuously converted to aqueous sulfuric acid using a polyacrylonitrile-based activated carbon fibre catalyst (PAN-ACF) in a packed-bed reactor system. The qualitative effects of residence time and oxygen, nitrous oxide, sulfur dioxide, and water concentrations were reported in Part 1. The conversion conditions were chosen to be typical of those expected in flue gas streams: sulfur dioxide 20-1000 ppmv, oxygen 0-10 vol.% and water 0-20 vol.%. A power-law model was developed to describe the steady-state concentration of sulfur dioxide in the exit gas. Sulfur dioxide reaction rate was proportional to catalyst weight, oxygen concentration to the 0.25 power, sulfur dioxide concentration to the 0.123 power and water concentration to the 1.01 power. The model was used to compare the effects of reactor operating conditions on the outlet concentration of sulfur dioxide.