In this contribution, a CFD technique has been used to study the effects of operational parameters on the amount of hydrodesulfurization (HDS) and hydrodearomatization (HDA) conversions in the trickle bed reactor (TBR). The Eulerian-Eulerian multiphase approach has been used to simulate multiphase flow conditions with appropriate models to account interphase interactions at TBR. Due to the importance of porosity distribution effect on the hydrodynamics behavior and reaction conversion, an appropriate trilobe porosity model has been implemented in the simulation models. The studied parameters are temperature, pressure, liquid phase velocity, and gas phase hydrogen sulfide concentration. The simulation results show good agreement with the reported experimental data.

Spent caustic wastewater is one of the most important environmental challenges due to high alkalinity, the presence of sulfur compounds and non-biodegradable pollutants. Therefore, in this research, the effective parameters of Electro-Fenton process including pH range (2-5), H2O2/COD (0.2- 0.745), temperature (20-60 °C), reaction time (45- 135 min) and current density (5-20 mA/cm2) have been investigated on the COD removal efficiency by adopting response surface methodology (RSM). The results indicated that H2O2/COD, temperature, pH, current density and reaction time have the most effect on the pollutants removal, respectively. The optimum conditions have been found at pH =4.8, current density =14.8 mA/cm2, temperature =57 °C, reaction time =63 minutes and H2O2/COD =0.63 with 96% COD removal efficiency. According to the results, by changing of initial COD within 12,500 to 60,000 mg/L range at the optimum conditions, the pollutant removal efficiency has been increased from 94% to 97%.

In this research, an air gap membrane distillation (AGMD) pilot was used for the tertiary treatment of effluent from Bandar Abbas oil refinery’s wastewater treatment unit. The commercial type membranes used in this system were with two different pore sizes 0.22 and 0.45µm, made of PTFE material with PP support. The cold flow was kept constant at 20 °C, and the effect of some process factors on the amount of produced water flux such as feed temperature (hot flow), air gap, concentration of wastewater, and membrane pore size were studied as Feed temperatures were equal to 40,50,60,70 and 80 °C, air gaps were equal to 6 and 12 mm, feed concentrations were equal to 780,2100,3250,4400 and 5200 μs/cm.  Also, the reduction of the amount of flux due to probable membrane fouling was investigated. Maximum produced flux was 16.44 kg/(m2.h) which was obtained using a 0.45 micron membrane, 6 mm air gap, and feed temperature of 80 °C. Increasing the air gap from 6 to 12 mm decreased the flux about 34%, while reducing the electrical conductivity from 4400 to 780 μs/cm, the amount of flux showed only 28% growth. Also, after about 30 hours of using the membrane without any cleaning system, the flux reduction was observed about 12%. Finally, according to the analysis of final purified water by membrane distillation method, the amount of TDS maximum 7.8 mg/L, COD about 4 mg/L, and chloride less than 8 mg/L have been obtained; in addition,  it has well been illustrated that the effluent of Bandar Abbas refinery’s wastewater plant by using membrane distillation supplementation can be used at all different sections of industry.

The texture of rock has a significant effect on production rate of hydrocarbon reservoirs and controls the   required pressure drops in fluid movement and production. In the reservoir zones that possess poor pore  connections, an inadequate network is formed and therefore the recovery factors are relatively small. The study of capillary pressure curves and thin samples reveals that rocks with vuggy porosities exhibit a good flow behavior and can be categorized as good reservoir rocks. It was also found that a full or partial reservoir rocks with inter-crystalline porosity possess low fluid recovery which is due to the weak connection between pores and their connecting throats.

Preparing drilling fluids is the most important part of the drilling operation of oil and gas wells that the use of advanced and beneficial technologies in their production can be closer to their performance and efficiency than the ideal values. Colloidal gas Aphron (CGA) based drilling fluids with advanced technology of aphron micro-bubbles and particular for Under Balance Drilling (UBD) are one of the newest technology that is used in the drilling of low pressure reservoirs. With production of aphron oil-based drilling fluid can be achieved together positive and valuable properties of oil-based drilling fluids along with special properties such as lost circulation of aphron based drilling fluids. Stability over time is the most important characteristic of aphron based drilling fluids that can be influenced on desirable rheological properties and control of lost circulation in this type of fluids. In this study, aphronized fluid with 2.14 mole percent surfactant and 15.01 kg/m3 polymer concentration has the highest stability over time, lowest yield loss and the lowest bubble size changes that these concentrations are presented as optimal concentration of surfactant and polymer.

In this paper, the oxidative desulfurization process has been studied using MoO3/g-C3N4 mechanically synthesized catalyst. At first, Dibenzothiophene (DBT) was selected as the target compound for synthesis of the model oil, and this model was used to optimize operating conditions. Also, H2O2 and acetonitrile were used as oxidant and extract solvents respectively. The effect of molybdenum loading on g-C3N4 and the operating conditions related to the ODS process including temperature, amount of catalyst, H2O2/DBT molar ratio, and time of reaction was investigated using the Box-Behnken (BB) method in experimental design. The maximum efficiency of DBT removal was obtained about 97.7%, at optimum conditions of 70 °C, catalyst content of 0.04 g, H2O2/DBT=8.44, and within 55 min reaction time. Also, the regeneration of the catalyst was evaluated four times, showing yield decreasing 6% for 10% MoO3/g-C3N4. Finally, at optimum conditions, performance of the catalysts in the removal of sulfur compounds of gasoline and gas oil from Oil Refining & and Distribution Company was investigated, and the obtained efficiencies of sulfur removal were 58.35% and 41% respectively. The MoO3/g-C3N4 catalyst was characterized by XRD, FTIR, EDX, FE-SEM, and BET analyses.

Ultrasound assisted oxidative desulfurization (UAOD) is a new process for the sulfur removal from different middle distillate cuts. In the UAOD process, at first, the sulfur-containing compounds are oxidized using a suitable oxidation system under ultrasound irradiation. Then, the oxidized sulfur-containing compounds are separated by solvent extraction. In the present study, the effect of interfacial tension between aqueous and hydrocarbon phases on the sulfur removal of diesel fuel has been investigated for the first time. The selected oxidation system was hydrogen peroxide/formic acid system. In this regards, three different surfactants including anionic, cationic, and nonionic surfactants have been evaluated. The results revealed that the application of sodium dodecyl sulfate (SDS) as an anionic surfactant and cetyltrimethylammonium bromide (CTAB) as a cationic surfactant leads to the sulfur removal of 82.65 and 83.10% after oxidation followed by solvent extraction respectively. The sulfur removal in the absence of surfactants was 81.61% in the same oxidation and extraction conditions. The application of span 60 as a nonionic surfactant leads to a decrease in sulfur removal to 78.65% in the same oxidation and extraction conditions. However, the application of span 60 leads to about 3% increase in the sulfur removal in comparison with the case without surfactant after the oxidation step. Therefore, the addition of surfactants can lead to a positive effect on the oxidation step due to decreasing the interfacial tension between aqueous and hydrocarbon phases and a negative effect on the extraction step of the UAOD process.

The fossil fuel sources are decreasing, and the use of biofuels has been recently considered. Among biofuels, biodiesel is considered more because of the environmental benefits. In this study, CaO/CuFe2O4/C nanocatalyst was used to produce biodiesel from Moringa oleifera oil. Different analyses such as TGA, EDX, XRD, FTIR, SEM, and TEM were applied to characterize physical and chemical properties of the CaO/CuFe2O4/C nanocatalyst. Also, Taguchi method was used to determine the biodiesel yield. Moreover, the effective parameters such as methanol/oil ratio (1:12 mol/mol), reaction time (4 h), reaction temperature (60 oC), and catalyst content (3%) were determined as optimal conditions on biodiesel production yield. Additionally, the maximum biodiesel yield was determined 98.69% in these conditions. Moreover, the physical properties of biodiesel/diesel mixtures like density, flash point, kinematic viscosity, pour point, and cloud point were studied, and the results were compared with ASTM D14214 and ASTM D 6751 standards. Finally, the results showed that these properties were in the standard range; in addition, pour point and cloud point are not proper for cold weather.

Dispersed water-in-oil as a stable emulsion causes numerous problems in extraction, transportation and refining of the crude oil. In the most desalting units, high voltage electrical field is utilized to separate water and ionic components from the crude oil. The efficiency of desalting units depends on operational conditions and hence in this study the result of several parameters on salt content of output crude oil in a desalting unit was considered for both theoretical and experimental studies. For this goal, optimized artificial neural network (ANN) using cuckoo optimization algorithm was applied to simulate the process. The optimum temperature, water  injection rate, retention time, differential pressure of mixing valves and injection rate of demulsifier were predicted by the consequences of simulation as the optimum value for each of the parameters was respectively equal to 79 ppm, 3.25%, 8.5 bar and 90 ppm. Then, because of the significant effect of the demulsifiers, the variation of each parameter was evaluated in the presence of four types of demulsifier separately. The results showed that an increase in the basic sediment and water content (BS&W) and specific gravity of crude oil has adverse effects on desalting process efficiency.

The cracked fuel oil product (CFO) derived from the olefin process is a complex mixture of the polycyclic aromatic hydrocarbons (PAHs) with 13 to 31% of naphthalene. In recent years, new applications for industrial and extremely pure naphthalene have been developed. Therefore, an alternative method of the distillation and catalytic hydrogenation must be chosen to reduce the economic cost and environmental impact resulting from the increase in demand for pure naphthalene. In the present study, purification of naphthalene from a CFO using the crystallizations followed by the solvent extraction process has been compared with the distillation method. The Box-Behnken design (BBD) as a method of the response surface methodology (RSM) was applied to minimize the number of runs and process optimization. The crystals’ purity of 73.71% and the crystallization yield of naphthalene of 96.73% have been achieved at an optimum cooling temperature of 25 °C, which at lower temperatures, the yield of naphthalene recovery will be lower. The melting temperature, the extraction yield and the purity of naphthalene were 80.13 °C, 97.36% and 99.42%, respectively under optimum operational conditions of extraction temperature of 15.08 °C, phenol/methanol volume ratio of 1.01, and solvent/feed volume ratio of 1.72. The statistical results indicated that the response surface quadratic model for our parameters was significant (p-value <0.0001) and a perfect correlation (R2=0.9989) between the statistical model (Design-Expert) and experimental data was found. Furthermore, according to the analysis of variance (ANOVA), the temperature of extraction and its interaction with the phenol to methanol volume ratio has a significant impact on the melting temperature. Also, the solvent mixture will be highly recoverable from methanol and phenol. In general, our results suggest that the introduced approach is an efficient and promising technique for producing native naphthalene from CFO.