STUDY OF THE PROCESS OF OXIDATIVE DESULFURIZATION OF DIESEL FUEL IN THE PRESENCE OF CO-CATALYSTS

Continuous growth in consumption of oil in the world, as well as ever-increasing quality requirements stimulate the search for new scientific and technological solutions to directionally affect the characteristics of petroleum products, including their chemical composition. The advantages of oxidative desulfurization before hydrotreating are the absence of the need to use hydrogen, as well as small capital and energy costs, since the method does not require high temperatures and pressures. The purpose of this work was to study the oxidation process of diesel fuel and to search for the optimal mode of oxidative desulfurization of diesel fuel in the presence of transition metals salts with the addition of mineral acids. The object of the study is a straight-run diesel fraction of the Pavlodar Petrochemical Plant with boiling temperatures of 180-350°C. The oxidation process was carried out with hydrogen peroxide in the presence of salts of the transition metals molybdenum, vanadium and tungsten. The article defined the basic physico-chemical characteristics of straight-run and desulfurized diesel fractions. The optimal catalyst (Na2MoO4) was selected at a molar ratio of metal to sulfur of 1:100 for the oxidation process of straight-run diesel fractions. As a result of oxidative desulfurization of diesel fuel in the presence of sodium molybdenum perox complexes, the total sulfur content decreased by 42.9%, and with the addition of sulfuric acid by 56.5%. An increase in the cetane index from 56.3 to 58.6 was revealed in the presence of sodium molybdate with the addition of sulfuric acid.

Kinematic Viscosity Prediction Guide: Reviewing and Evaluating Empirical Models for Diesel Fractions, and Biodiesel-Diesel Blends according to the Temperature and Feedstock

Experimental analysis of viscosity can be a straightforward and inexpensive analysis for few samples. However, in industrial processes that have high demands of properties measurements, the determination of viscosity and other properties involves time-consuming with sampling, analysis and availability of results. Also in refineries, the sampling routines for experimental determination of the viscosity of streams are not enough to represent variations that occur in the process, such as the shift of an oil tank in distillation units. In addition, besides requiring cost of operating personnel and laboratory analyst, all of these steps can take up to one shift until the result is available. Therefore, as an alternative, the use of predictive methods of kinematic viscosity are essential. Empirical methods have been used in simulations and design calculations of streams and mixture at industries regarding kinematic viscosity (KV) of petroleum fractions and fuels at different temperatures. However, there are uncertainties about the most accurate method to use at specific condition (temperature, feedstock, volume fraction) which might affect the KV prediction of fuels with unknown composition. Therefore, we assembled and evaluated several methods to predict KV of different diesel systems. In addition, new methods for predicting KV of diesel fractions at several temperatures were also developed for improving the estimation accuracy. As a result, we developed a guide with suggestions of the most accurate models to be applied for diesel fraction from assays, diesel fractions S500 from blend system at several temperatures, and biodiesel-diesel blends at different temperatures, volume fractions and feedstock.

The Effect of Carbonates and Silicates on the Cracking of a Mixture of Fuel Oil and Mechanically Activated Oil Shale

The study cracking of a mixture of mechanically activated oil shale (MO OSh) and fuel oil, a mixture of demineralized MO GS and fuel oil has been investigated. The data on the composition of liquid products showed that after the removal of mineral components, oil shale is more easily destroyed due to the release of kerogen. It is shown that in the obtained liquid products of the cracking of the mixture of fuel oil – demineralized MO OSh, the proportion of oils increases to 74.6 % wt. In the composition of gaseous products of cracking, the amount of hydrogen, methane and ethane is noticeably reduced. According to the data on the fractional composition of liquid products, it was found that during the cracking of mixtures of fuel oil and MO HS, after the removal of carbonates and silicates, the proportion of gasoline and diesel fractions inc

The effect of a nickel-containing catalyst on the tar carbonization process

Tar carbonization was studied in the absence or presence of the 7% Ni/CNT catalyst. It was shown that tar carbonization at a temperature of 350 °С without the catalyst leads to the formation of gaseous and liquid products and oil coke. Thermolysis products are formed via the separation of lateral hydrocarbon chains from the initial polyaromatic hydrocarbons. Gaseous products consist of С1-С6 hydrocarbons and sulfur-containing gases H2S and COS. Fractional composition of the liquid thermolysis products was studied. It was found that 50 % of the liquid products are represented by gasoline and diesel fractions. The 7% Ni/CNT catalyst was prepared by impregnation. The effect of this catalyst on the tar carbonization in the temperature range of 300–550 °С was studied. The addition of the 7% Ni/CNT catalyst to tar increased its yield and decreased the sulfur content due to partial conversion of sulfur to hydrogen sulfide and COS, which are removed with the gas phase. The electron microscopy study showed that the oil coke obtained upon catalytic tar carbonization is reinforced with carbon nanotubes.

INFLUENCE OF ULTRASOUND ON THERMOCHEMICAL PROCESSING OF FUEL OIL WITH SHALE ADDITIVES AT DIFFERENT PRESSURES

This article presents the results of the influence of ultrasonic exposure (UE) on the process of thermochemical destruction of fuel oil in the presence of shale of Kenderlyk field at different pressure intervals (3.5-5.5 MPa). A number of experiments were performed before and after ultrasonic exposure to select the working pressure for thermochemical processing of shale and fuel oil. Analysis of the results of pressure influence on the yield of thermochemical processing products shows that with increasing process pressure there is an increase of yield of gas, gasoline fraction (up to 180°C) and diesel fractions (180-360 °C) reaching maximum values in the range of 5.0 MPa. The yield of fractions that boil off at temperatures more than 360 °C are decreased with increasing pressure in the range of 3.5-5.5 MPa, and then begins to grow sharply with increasing pressure. After ultrasonic exposure at a temperature of 80 °C, a frequency of 22 kHz and 25 minutes of soaking the total yield of light distillates increases to 65.0 mass%. This is 10 units higher than without the use of UE.

Revealing the effect of catalyst concentration on the process of fuel oil refining using the technology of aerosol nano catalysis

The primary oil processing product is a mixture of different hydrocarbons. One of the hard-to-process petroleum products is fuel oil. This paper considers a method to derive clear (light) fractions of petroleum products by the catalytic processing of fuel oil on a zeolite-containing catalyst at 1 atm under the technological conditions of aerosol nanocatalysis. The prospect of the catalytic processing of a viscous residue ‒ fuel oil ‒ has been analyzed and estimated. The process is carried out by dispersing the catalytically active component in a vibratory-fluidized layer. Chemical transformation occurs during the constant mechanochemical activation of catalyst particles by forming an aerosol cloud in the reactive volume. Natural zeolite catalyst of the type Y was selected for research. Methods for separating the gasoline and diesel fractions of light hydrocarbons and for analyzing the gas phase have been given. The effect of the concentration of zeolite catalyst aerosol on the composition of cracking products (the yield of the gasoline and diesel fractions of light hydrocarbons) has been studied. It is noted that the rate of the course of fuel oil processing in the aerosol of the catalyst is 1.5‒2 times higher than that in thermal processing. It has been found that in fuel oil processing based on the aerosol nanocatalysis technology, the concentration of the catalyst can be controlled to produce the final product. The study results have shown that the optimal conditions for processing fuel oil in the aerosol of the catalyst should be considered 773 K, a frequency of 5 Hz, a pressure of 1 atm. At the same time, a concentration of the catalyst of 1‒5 g/m3 should be considered optimal for the output of a light fraction of hydrocarbons. In this case, the yield is up to 80 % of the fraction in the laboratory. It was found out that during the processing of fuel oil, the concentration of the catalyst makes it possible to optimize the output of light oil products under the technological conditions of aerosol nanocatalysis

Involvement of products of thermal processing of polymer waste into the raw material pool of oil refinery plants

The directions of involving the products of thermal processing of polymer waste into the raw material pool of oil refineries are considered. A detailed analysis of fractions 85-180 oC, 180-360 oC and 360-KK oC, isolated from thermolysis products, has been carried out. Fractions 85-180 °C, 180-360 °C of thermolysis oil are characterized by a high content of organosulfur compounds, which necessitates their hydrotreating before use. After desulfurization, gasoline and diesel fractions can be used in the composition of gasoline and diesel fuels, respectively. The diesel fraction of 180-360 °C of thermolysis oil has a high cetane number and can be considered as a cetane-increasing component. Fraction 360-КК оС thermolysis oil is a potential component of catalytic cracking feedstock. The highest degree of conversion and the yield of valuable components (gasoline, propylene, butane-butene fraction) are achieved during cracking of feedstock containing 30 wt. % of the heavy part of thermolysis oil.