On reaction models of regeneration process for NH3-based

In this paper, the effects of the reaction models for the condenser and reboiler were investigated by carrying out rate-based simulations on the NH3-based CO2 regeneration process. The predicted parameters in the regeneration process agree well with the experimental results when using the kinetic reaction model for both the condenser and reboiler. The chemistry model for the reboiler significantly underestimates the CO2 output and overestimates the regeneration energy, but has little effects on the component concentrations in the gas product. When using the chemistry model for the reboiler, the underestimation of the CO2 output mainly comes from the reboiler stage and it is due to that the HCO3- in the liquid phase does not decompose, but forms in the reboiler stage, while the overestimation of the regeneration energy not only comes from the underestimation of the CO2 output, but also the overestimation of the reboiler heat duty, which is due to the higher predicted bottom temperature of the stripper. The chemistry model for the condenser only significantly underestimates the NH3 concentration in the gas product. (C) 2014 The Authors. Published by Elsevier Ltd.