جستجوی مقالات مرتبط با کلیدواژه "crude oil" در نشریات گروه "شیمی"

In this study, salt separation from crude oil was investigated using nickel oxide nanoparticle absorber. The effect of parameters such as pH (4, 5, 6, 7. 8, and 9), time (15, 30, 45, and 60 min), amount of adsorbent (0.25, 0.3, 0.5, 0.75, and 1 g), and temperature (40, 50, 60, and 80 ℃) on the degree of salt separation from crude oil was studied. When the pH was decreased, the salt absorption was decreased.  Increasing the temperature increased the desalting percentage. Also in the alkali range due to the presence of OH- ions in the solution, there is a possibility of better complexation between the adsorbent and the cations. Therefore, the best adsorption was observed at near-neutral pH. The best conditions for salt absorption, pH 7, temperature 80 ℃, absorbance 0.75 g, and absorption time 45 min were obtained.

Determination of wax appearance temperature is a crucial specification in the transportation and storage of crude oil or heavy refinery products same as fuel oils. In this work, to determine wax appearance temperature different applicable methods were tested and developed. At first, the microscopic experiments were applied to different samples. Then the variation of viscosity versus temperature was monitored. To determine a feasible method to be applied in the fields, the variation of viscosity versus temperature was monitored. It was declared that at the wax appearance temperature a deep change in viscosity happened. Eventually, the wax appearance temperature of different crude oil including Iranian or heavy crude oil can be determined by the viscosimetry method. In the related experiments, the negative effect of water sediments and wax crystals was eliminated. It was also declared that the wax appearance temperature could be varied by variation of density, wax content, pour point, and asphaltenes of the samples. To correlate between input and output variables three different modeling methods were tested and implemented. The Artificial neural networks, Neuro-fuzzy, and regression models were tested to derive the most accurate correlation. The statistical studies approved that the regression models have suitable accuracy. The results of the regression model declared that the interaction effect of density and pour point and the effect of asphaltenes as one of the main input variables have the greatest impact on the wax appearance temperature.

In this research, the process of desalting and water removal from crude oil by ultrasonic laboratory scale has been investigated. The effect of main parameters including ultrasonic radiation parameters, the input power of radiation, and radiation time, as well as functional parameters such as temperature and injection rate of emulsion breaker, have been investigated on the removal efficiency of salt and water. The results showed that using ultrasonic waves, the amount of Ahwaz crude oil decreased by 40 ppm emulsion breaker from 471 mg/L to 76.18 mg / l, and water content decreased from 9.19% to 1.1%. The rate of desalinization was 83.38% and the rate of dehydration was 88.03%. The amount of Ahwaz 4 crude oil was reduced by injection of 30 ppm emulsion breaker from 353 mg/L to 49.2 mg/L, and water content decreased from 11.36% to 2%, with a desalting rate of 86.06% and a water abstraction of 82.4% have been. These results were obtained at the highest test temperature of 80 °C and 10 KHz, which, with a near approximation to unit efficiency, reduced the use of the demulsifier. In optimal operating conditions, the results show that ultrasonic radiation can be effective in reducing the desalination of crude oil by reducing the amount of emulsion breaker and increasing process efficiency. Also, the results of the research show that the combination method of ultrasound and emulsion breaker is the best way to use emulsion breaker.

In thisarticle, a statistical modeling methodology was presented for the optimization of Lavan oil refinery atmospheric distillation unit operation. The simultaneous effects of crude oil and gas condensate flow rates on liquefied petroleum gas, light and heavy naphtha, middle distillate (gasoil), and fuel oil production were investigated using Response Surface Methodology (RSM) by Design Expert Software. For this purpose, 623 experimental data under various operating conditions were used. To identify the significance of their effects and interactions, analysis of variance (ANOVA) was performed for each parameter on the production of liquefied petroleum gas, light and heavy naphtha, middle distillate (gasoil), and fuel oil. The results indicate that the R2 values are more than 0.92 and adjusted R2 are in a reasonable agreement with R2.  After that,optimization was also carried out to increase the production of valuable products such as light and heavy naphtha and to reduce the fuel oil production as undesirable products. According to the optimal conditions and consideration of operational constraints, the maximum amount of naphtha production and minimum fuel oil production as the main goal of this study were gained in the total feed flow rate 56500 BPD and with a 57% gas condensate and 43% of crude oil blending. Also, the process modifications were applied and the optimum operating conditions were implemented successfully.