چكيده به لاتين
Desulfurization of petroleum products is one of the most important processes that has received special attention in recent years due to environmental standards. The aim of this research is to remove dimethylsulfide from the mercaptanized condensate to achieve deep desulfurization of the condensate. For this purpose, activated carbon with the origin of walnut shell and pistachio shell as adsorbent and normal hexane and dimethyl sulfide solution with different weight percentages were prepared and the adsorbents were modified in three ways by using acid, ion, and ionic liquid and the modification method was selected with ion. Four ions of silver, copper (I), copper (II), and iron (III) were compared with each other for ionic modification and silver was selected. Silver ion was added to the adsorbent with different percentages by weight and their performance was compared with each other, and silver ion with 6% by weight showed the best performance. The selected adsorbent was characterized by BET, TPD, SEM, and XRD methods. Adsorption was modeled with Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich isotherms, and adsorption kinetics was also modeled with pseudo-first-order and pseudo-second-order models. Freundlich model with relative error of 0.045% and pseudo-first-order model with regression coefficient of 0.99 were selected as isotherm and kinetic models, respectively. Also, the experimental results of the adsorbent were modeled with the simplified local density model and parameters of Lennard-Jones interaction energy, adsorbent pore length, adsorbent specific surface area and binary interaction parameter were modeled for the first time in the liquid phase. The Lennard-Jones interaction energy parameter of dimethyl sulfide and the adsorbent increased with the increase of the surface adsorption capacity of the adsorbents, and the Lennard-Jones interaction energy parameter of normal hexane remained almost constant, and the difference between these two parameters also increased with the increase of the surface adsorption capacity of the adsorbents. The raw adsorbent with AAD of 0.0072 mmol/g had the lowest error, and the adsorbents modified with the silver ion and with weight percentages of 2, 4, 6, 8, and 10% had errors of 0.0727, 0.0377, 0.0601, 0.0605, and 0.0634 mmol/g respectively. In this way, the effectiveness of this model for surface adsorption of liquids has been proven.
