Experimental and Simulation-Based Study of Acid Gas Removal in Packed Columns with Different Packing Materials

In this study, both experimental and simulation approaches were employed to investigate the removal efficiency of gaseous pollutants using two different types of packing materials-random and structured packings-under varying gas flow rates and column diameters. A synthetic gas mixture containing 2200 ppm H2S and 26.75% CO2 was used to evaluate the performance of the system. Simulation studies were conducted using Aspen Plus (TM) V9, and the results were validated with experimental data. H2S removal efficiencies were found to range between 79% and 98%, while CO2 removal ranged from 6% to 20%. Comparative analyses revealed that an increase in gas flow rate and column diameter led to a decrease in pollutant removal efficiency for both types of packings. A previously unobserved packing-dependent scaling effect was revealed: increasing column diameter decreases removal efficiency for random packings but enhances it (up to a threshold) for structured packings, offering new scale-up guidelines. Most notably, a previously unobserved trend was identified: increasing column diameter exerts opposing effects on removal efficiency depending on packing type-a packing-dependent scaling behavior with significant implications for industrial column design. The findings provide valuable insights into the design and optimization of industrial-scale gas treatment systems, demonstrating that simulation data can effectively support the selection of appropriate column dimensions, gas flow rates, and packing types for varying pollutant concentrations. A mechanistic analysis revealed that the superior H2S removal over CO2 arises from its higher solubility, instantaneous reaction with OH-, and greater enhancement factor, with structured packings mitigating maldistribution effects at larger column diameters-offering new scale-up insights supported by the literature.