Dynamic Modeling to Minimize Energy Use for CO2 Capture in Power Plants by Aqueous Monoethanolamine

A dynamic rate-based model was developed for stripping in CO2 capture from coal-fired power plants with 30 wt % monoethanolamine (MEA). The model, created in a flow sheet of Aspen Custom Modeler, was based on the film theory for liquid and vapor phases. It takes into account the impact of equilibrium reactions oil the mass transfer, thermodynamic nonidealities, and the hydraulics of the structured packing. With this model, steady state analyses were. carried out for the stripper to understand the effect of the]can loading and the height of the packing on total equivalent work and find optimum operating conditions that minimize power plant lost work. Two dynamic strategies with control configurations are proposed to run the stripper in a flexible operation during the period of electricity peak load and prices. Open loop responses demonstrated some differences in dynamic behavior and steady state values for proposed dynamic strategies. One of the approaches increased the CO2 removal by 1% at the reduced steam rate and provided faster response of the stripper to a step change in the reboiler heat rate.