Modeling and optimization for HCl oxidation combining fluidized bed with multi-stage quenching adiabatic fixed bed reactor

A novel HCl oxidation technology combining fluidized bed reactor (FBR) with multi-stage adiabatic fixed bed reactor (MSAFBR) in series was proposed. The operational parameters of HCl oxidation process, such as variety and flow rate of quench gas between MSAFBR, molar ratio of HCl to O₂ in feed gas and catalyst dosage, were optimized based on the mathematic one-dimensional model established on the mass, energy and momentum balances. The results showed that liquid oxygen was more suitable in this technology. With liquid oxygen as the quenching gas, the effects of composition of the feed gas on optimum operating curve and catalyst dosage were investigated. The results demonstrated that the least amount of catalyst used in FBR and MSAFBR was 4.3 and 8.6 t, respectively, when the flow rate ratio of HCl to O₂ in feed gas was 1:0.7. Meanwhile, under the best flow rate of liquid O₂, HCl conversion rate of 85% could be obtained.