Removal of H2S from crude oil via stripping followed by adsorption using ZnO/MCM-41 and optimization of parameters

In the present work, H2S of crude oil was removed via a two-step method including stripping followed by adsorption. First, ZnO/MCM-41 adsorbents containing 5, 17.5 and 30 wt% of zinc were synthesized and characterized using XRD and nitrogen physisorption. Then, these materials were used as adsorbents for the removal of the H2S stripped from crude oil. At second step, the H2S of crude oil was extracted to gas phase by hot stripping. The obtained extract was collected in a storage tank for the subsequent H2S adsorption process. A threefactor Box–Behnken design with five center points and one response was performed for the optimization of adsorption of H2S. The influence of process parameters and their interactional effects on the adsorption of H2S were analyzed using the obtained adsorption experimental data. A model including three important factors, i.e., temperature, space velocity and amount of supported zinc and their interactions, was developed to generate the optimum condition. The point of Zn = 30 wt%, T = 300 C and space velocity = 3,000 h had the optimum point with the highest break point time (tbp = 973 min).