Hydrogen Sulfide Removal Using Various Metal Oxide Nanocomposite from Drilling Fluid: Optimization, Kinetic and Adsorption Isotherms

In a drilling operation, the existing hydrogen sulfide in oil and gas reservoirs can be solved in drilling fluid and cause some environmental problems and life-threatening situations to personnel. Therefore, hydrogen sulfide removal of drilling fluid is so important. In this work, in order to hydrogen sulfide removal from drilling fluid, zinc oxide nanoparticle, silica nanoparticle and silica/zinc oxide nanocomposite with different ratio were synthesized by precipitation and sol-gel method and characterized by x-ray diffraction, fourier-transform infrared spectroscopy, Field emission scanning electron microscopy, energy dispersive x-ray and brunauer–emmett–teller. The Design Expert software, I-optimal, was used to design the experiments and the optimum condition for hydrogen sulfide removal was determined. Also, the effect of nanomaterial concentration, hydrogen sulfide concentration, contact time, pH and type of nanomaterial on removal of hydrogen sulfide was investigated. the results show, the optimization of removal at nanoparticle concentration, 0.1 and 0.9 wt.%, hydrogen sulfide concentration, 800 ppm, contact time, 3 min., pH, 12 and ZnO/SiO 2 nanocomposite with 3:1 ratio is about 92.6 and 97.2%. investigation of the reaction kinetic showed that hydrogen sulfide removal had a very high rate, so that time parameter has a low impact on the removal process. Also, the kinetic adsorption was pseudo-first order. Adsorption of hydrogen sulfide followed Freundlich isotherm model and multilayer adsorption. The reusability of nanocomposite is four cycles for hydrogen sulfide removal more than 50%, which was significant in industrial processes.