Abstract: Hollow fiber membrane contactor (HFMC) units are one of the most promising technologies for improving conventional absorption processes. Traditionally, the optimization and control of this process is based on simplified mathematical models or linearized control proposals that may present limitations. This work introduces a robust control based on modeling error compensation (MEC) applied to CO₂ and H₂S absorption in a HFMC for natural gas sweetening. The HFMC model considers the concentration distribution in radial and axial coordinates. A classical PI controller and a sliding model controller (SMC) are applied for comparison purposes. Simulation results show that the proposed control MEC is suitable for regulating the sour gas concentration to values that reduce their presence at the HFMC from 0.85% to 0.45% (mol) of CO₂ and from 4 to 1.2 μl·L^-1 of H₂S, independent of external disturbances and setpoint changes. Likewise, MEC’s ability to compensate for modeling uncertainties through a simple and easily implemented design provides robust performance that satisfies international standards in natural gas quality, showing a 40% better performance according to the integral of squared error compared with the SMC controller.

Key words: Robust control, CO₂/H₂S absorption, HFMC

摘要： Hollow fiber membrane contactor (HFMC) units are one of the most promising technologies for improving conventional absorption processes. Traditionally, the optimization and control of this process is based on simplified mathematical models or linearized control proposals that may present limitations. This work introduces a robust control based on modeling error compensation (MEC) applied to CO₂ and H₂S absorption in a HFMC for natural gas sweetening. The HFMC model considers the concentration distribution in radial and axial coordinates. A classical PI controller and a sliding model controller (SMC) are applied for comparison purposes. Simulation results show that the proposed control MEC is suitable for regulating the sour gas concentration to values that reduce their presence at the HFMC from 0.85% to 0.45% (mol) of CO₂ and from 4 to 1.2 μl·L^-1 of H₂S, independent of external disturbances and setpoint changes. Likewise, MEC’s ability to compensate for modeling uncertainties through a simple and easily implemented design provides robust performance that satisfies international standards in natural gas quality, showing a 40% better performance according to the integral of squared error compared with the SMC controller.

关键词: Robust control, CO₂/H₂S absorption, HFMC