Investigating the factors affecting the optimization of hydrogen sulfide gas adsorption parameters on the new MIPs@H2S nanoadsorbent using the response surface method

Abstract

Hydrogen sulfide is produced through industrial sources such as textiles, oil and gas refineries, and paper. Exposure to high concentrations of hydrogen sulfide has caused death in industrial environments. Various methods, including adsorption, have been considered a suitable approach due to low energy consumption, lower costs, and high efficiency. In this research, the synthesis and optimization of MIPs@H₂S-specific nanoadsorbent of hydrogen sulfide gas were done using the response surface method. Initially, the synthesis of MIPs\NIPs@H₂S nanoadsorbent was done by the SIP method and four variables, including dose, temperature, concentration, and flow, which were decided upon utilizing RSM with central compound design. Thirty experiments were also designed to optimize the variables affecting the adsorption capacity. Besides, physical characteristics were determined by FTIR, XRD, FE-SEM, BET, and total pore volume and nitrogen adsorption. The analysis of variance indicated a linear model, while the adsorbent dosage and temperature are the most important process variables to calculate the optimal operating conditions of the process affecting the H₂S adsorption capacity. The projected results of the linear correlation demonstrated excellent concurrence with the experimental observations. The optimal process variables obtained from numerical optimization were equal to the adsorbent dose of 1.32 gr, concentration of 752.2 PPM, flow of 85 ml/min, and temperature being equal to 42.5 °C. Based on the optimal conditions, the highest adsorption capacity of MIPs@H₂S (61.28 mg/g = 94.7%) and NIPs@H₂S (6.14 mg/g = 9.14%) was obtained. The C.C.D. method is suitable for the optimization of hydrogen sulfide adsorption experiments and improved nanoadsorbents. The contours showed that increasing the dose, concentration, and flow along with decreasing the temperature increases the adsorption capacity and efficiency.