Removal of carbonyl sulfide at low temperature: Experiment and modeling

A mathematic model of carbonyl sulfide (COS) removal at low temperature with fouling of catalyst has been developed based on experimental results. Kinetic studies were conducted in a fixed bed reactor under atmospheric pressure and at low temperature (40-70 °C). Experimental results of breakthrough curves were used to obtain kinetic parameters accounting for axial dispersion, external and internal mass-transfer resistances as well as the sulphur deposition on inner-face of catalyst. Initial bulk porosity of particle (?_P0), deactivation coefficient (α), sulfide deposition coefficient (β) were used to quantify the behavior of COS removal at different operating conditions. Adsorption heat of H₂O and activation energy of COS removal was 21.5 and 62.4 kJ/mol respectively. The effects of flow rate, COS inlet concentration, temperature and relative humidity(RH) were analyzed, and it was found that relative humidity carried a heavier weight than temperature on ε_P0, α, β within our experimental conditions. The model agreed well with the experimental breakthrough curves and satisfactorily predicted the fixed-bed reactor performance, and this model can be used as a reliable tool for process design and scaling-up of similar system.