No abstract

The feasibility of removing sulfur from real light gas oil using inorganic liquids (NaOH, Ca(OH) 2 and HCl) at various concentrations assisted with ultrasonication was investigated in a continuous flow setup. Experimental results showed that at the optimum operating time (40 min), 68% of sulfur was removed under mild conditions using 10 wt. % NaOH. Ultrasonication not only facilitated sulfur removal but also improved gas oil properties by decreasing density and viscosity by 1.40 and 4.42%, respectively, while the cetane number (CN) was increased by 7.0%. Solute selectivity (S) depending on sulfur mole fraction (x S) was correlated using StatPlus 6.7.1.0 software and the following values have been obtained: S = 53.869e-2.552x S , and S = 29.573-41.878x s for mixtures of 10% Ca(OH) 2 + S-compound + oil, and 10% NaOH + S-compound + oil, respectively. The correlation coefficients (R 2) for the above equations were 0.9813 and 0.9611, respectively. An empirical correlation related to sulfur removal as a function of processing time and solvent concentration was found with R 2 = 0.956. The results of the present work confirmed the feasibility of employing the hybrid method of ultrasonication with using alkaline liquids for sulfur removal.

The operation of reforming catalysts in a fixed bed reactor undergoes a high level of interaction between the operating parameters and the reaction mechanism. Understanding such an interaction reduces the catalyst deactivation rate. In the present work, three kinds of nanocatalysts (i.e., Pt/HY, Pt-Zn/HY, and Pt-Rh/HY) were synthesized. The catalysts’ performances were evaluated for n-heptane reactions in the fixed bed reactor. The operating conditions applied were the following: 1 bar pressure, WHSV of 4, hydrogen/n-heptane ratio of 4, and the reaction temperatures of 425, 450, 475, 500, and 525 °C. The optimal reaction temperature for all three types of nanocatalysts to produce high-quality isomers and aromatic hydrocarbons was 500 °C. Accordingly, the nanocatalyst Pt-Zn/HY provided the highest catalytic selectivity for the desired hydrocarbons. Moreover, the Pt-Zn/HY-nanocatalyst showed more resistance against catalyst deactivation in comparison with the other two types of nanocatalysts (Pt/HY and Pt-Rh/HY). This work offers more understanding for the application of nanocatalysts in the reforming process in petroleum refineries with high performance and economic feasibility.

The feasibility of the removal of vanadium(V) from Iraqi crude oil using zeolite A was investigated. Different operating parameters such as adsorbent loading, vanadium loading, and operating time were studied for their effects on metal removal efficiency. Experimental results of adsorption test show that Langmuir isotherm predicts well the experimental data and the maximum zeolite A uptake of V was 30 mg/g. XRD and EDX analyses revealed the noticeable uptake of zeolite for V. In crude oil, experimental results indicated that for zeolite loading at 1 g/100 mL oil and within approximately 5 h, the removal efficiencies of V were 60, 45, and 33% at vanadium loadings of 75, 85, and 95 ppm respectively. While at 10, 20, 40, and 50 h the removal efficiency was 68, 75, 78 and 78% for 75 ppm of V loading. The equilibrium concentration of V in crude oil was attained after 40 h of operation. Long-term tests revealed the high stability of zeolite A for vanadium removal. Results depict that zeolite A could be advantageous for removal of V in the crude oil hydrotreating units.

The present study has been conducted to investigate the removal of vanadium from Iraqi crude oil by prepared zeolite nanoparticles. Ball milling was used as a top down approach to synthesize zeolite nanoparticles. Different variables such as adsorbent load ing, Vanadium loading, and operating time were investigated for their influence on Vanadium removal. Experimental results of adsorption test show that both Langmuir and Freundlich isotherms predict well with the experimental data. Kinetic analysis of the studied system gives the following linear equations, For Langmuir isotherm: