Equilibrium and kinetic studies in adsorption of H2S using coconut shell activated carbon xerogel: Effect of mass adsorbent and temperature

Abstract

The presence of acid gases like hydrogen sulfide (H2S) in natural gas, refinery gas, and coal gas necessitates their removal from the gas stream to prevent corrosion of pipelines and production equipment and to ensure safety due to the toxic nature of H2S. A study was conducted to synthesize an adsorbent that is made from coconut shell which is modified to form coconut shell-activated carbon xerogel (CSACX). The main objective is to determine the kinetic models’ equation and adsorption isotherms that are most suitable for the adsorption of hydrogen sulfide by using CSACX. Two parameters were studied which were the adsorbent mass and the gas temperature. The adsorption process could be mathematically represented using the Thomas Model, Yoon-Nelson Model, and Adam-Bohart. It is expected that the adsorption process is mathematically represented using the Thomas and Yoon-Nelson Model for both the effect of mass of adsorbent and effect of gas temperature. The kinetic models used were Pseudo-First Order and Pseudo-Second Order. Suitability of equation was determined by correlation coefficient (R2). The higher the R2, the more suitable the equation is to process. It is expected that the adsorption processes using the CSACX fit both pseudo-first and pseudo-second order equation. This means that both physisorption and chemisorption occur during the adsorption process.