No abstract

In this research synthesis, purification and characterization of six long-chain imidazolium based ionic liquids (ILs) including C 10 , C 12 , and C 14 alkyl chain with chloride and NTf 2 anions was investigated. All of these studied ILs were characterized using NMR, CHNSO, and DSC, and some impurities such as water, chloride, and metal contents were reported. The temperature dependence of some physicochemical properties such as density, dynamic and kinematic viscosity, refractive index, surface tension, and thermal stability of the synthesized ILs were also studied in the range 283.15 to 363.15 K, and the results were compared with those from the literature. Moreover, using the measured data, the thermal expansion coefficient and molar polarizability of the ILs were calculated. On the other hand the effects of alkyl chain length and anion were explained. The results revealed that although the refractive indices and viscosities increased as alkyl chain length increased, the density and surface tension results were reciprocally decreased. Besides, the results suggest that the synthesized ILs were the best choice as fuel additives.

No abstract

In the present work, H 2 S 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 H 2 S stripped from crude oil. At second step, the H 2 S of crude oil was extracted to gas phase by hot stripping. The obtained extract was collected in a storage tank for the subsequent H 2 S adsorption process. A threefactor Box-Behnken design with five center points and one response was performed for the optimization of adsorption of H 2 S. The influence of process parameters and their interactional effects on the adsorption of H 2 S 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 -1 had the optimum point with the highest break point time (t bp = 973 min).

No abstract