The Monte Carlo simulation is popular in engineering because it is a flexible simulation. It can reduce the uncertainty of the possibilities, and it can run a large number of cycles that are suitable for studying the kinetics and mechanism of adsorption, leading to better data accuracy than practical results. This simulation is chosen to investigate the phenomena of H2S gas adsorption in hydrogel biochar. Hydrogel biochar adsorbent is made from highly available biomass sources by using the pyrolysis process. There are two parameters studied: the effect of the flow rate of H2S gas and adsorbent bed height. This parameter can show the efficiency of the adsorption process. From this research, the kinetic model that suitable for this H2S gas adsorption is by First- Pseudo Kinetic model based on the correlation coefficient R2 values generated from the MATLAB program is between 0.7 to 0.9. Thus, physical adsorption is the best way to describe the adsorption in hydrogel biochar in which the uniform energies of adsorption on the surface of biochar and no shifting of adsorbate in the plane of surfaces. It can be concluded that at the optimize condition Langmuir's isotherm is the most suitable isotherm where the maximum amount of adsorption capacity is obtained, and the adsorption process occurs at monolayer of adsorbent with an equivalent adsorption site