Steady-state optimization and dynamic mode control in an MDEA-based CO2 absorption plant

JUAN PABLO GUTIERREZ; LILIANA ALE RUIZ; ELEONORA ERDMANN

Bahía Blanca

Congreso; IX Congreso Argentino de Ingeniería Química, CAIQ2017; 2017

PLAPIQUI-UNS-CONICET

In the amine-based CO2 absorption process, the energy requirement for the solvent regeneration is considerably high and different optimization strategies can be applied to minimize it. For this study, data and process information are obtained from a MDEA absorption plant located in the NOA Region, Argentina. After the steady-state is simulated, the optimal operative point in terms of consumed energy is identified. For the purpose, the ratio between the reboiler duty and the absorbed CO2 is considered as the objective function and two manipulated variables modified. Then, the conditions of the optimal case are simulated in Aspen Hysys v8.8 and the results are exposed. Once the optimization problem is solved, a decrease close to 50% in the reboiler duty is observed.In the second part of the study, base case and optimal cases are turned into dynamic mode. In this stage, the set points are established in accordance with the steady-steady cases results. In the discussion section, the evaluation of the controllers? time response and the level of the system stability are analyzed, compared and debated. The results show a good performance of the control scheme. According to the monitoring graphs, a good approximation to the complete stability of the optimal case is reached in shorter times than those observed in the base case. Then, the stablished optimal point is feasible, valid and controllable. In regard to the operability, the developed model is suitable to perform different operational strategies before carrying them out in-situ.