scholarly journals Study on Chemistry of Oxidative Desulfurization Process of High Sulfur Straight-Run Oil Fraction

2021 ◽  
Vol 15 (3) ◽  
pp. 414-422
Author(s):  
Serhiy Pyshyev ◽  
◽  
Bohdan Korchak ◽  
Denis Miroshnichenko ◽  
Bemgba Bevan Nyakuma ◽  
...  

In the article the chemistry of the noncatalytic oxidative desulfurization process of distillate oil fractions is analyzed. The study involves the characteristics of high-sulfur straight-run diesel fraction of narrow composition (593–623 K) before and after oxidation by air at 453–493 K and a pressure of 3.0 MPa. The composition of sulfur compounds in the raw material fraction was determined. It is shown that straight-run fractions of raw materials may also contain sulfoxides, which are products of oxidation of organosulfur compounds and are formed during storage of petroleum products. On the basis of IR spectroscopic studies of raw materials, oxidized products and model mixtures, the transformation depth of fr. 593–623 K sulfur compounds, which are distributed in the form of sulfones and sulfoxides in solid and liquid oxidation products, and partially remain in the purified fuel, was analyzed in the above-mentioned process.

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1050
Author(s):  
Sarrthesvaarni Rajasuriyan ◽  
Hayyiratul Fatimah Mohd Zaid ◽  
Mohd Faridzuan Majid ◽  
Raihan Mahirah Ramli ◽  
Khairulazhar Jumbri ◽  
...  

The biggest challenge faced in oil refineries is the removal of sulfur compounds in fuel oil. The sulfur compounds which are found in fuel oil such as gasoline and diesel, react with oxygen in the atmosphere to produce sulfur oxide (SOx) gases when combusted. These sulfur compounds produced from the reaction with oxygen in the atmosphere may result in various health problems and environmental effects. Hydrodesulfurization (HDS) is the conventional process used to remove sulfur compounds from fuel oil. However, the high operating conditions required for this process and its inefficiency in removing the organosulfur compounds turn to be the major drawbacks of this system. Researchers have also studied several alternatives to remove sulfur from fuel oil. The use of ionic liquids (ILs) has also drawn the interest of researchers to incorporate them in the desulfurization process. The environmental effects resulting from the use of these ILs can be eliminated using eutectic-based ionic liquids (EILs), which are known as greener solvents. In this research, a combination of extractive desulfurization (EDS) and oxidative desulfurization (ODS) using a photocatalyst and EIL was studied. The photocatalyst used is a pre-reported catalyst, Cu-Fe/TiO2 and the EIL were synthesized by mixing choline chloride (ChCl) with organic acids. The acids used for the EILs were propionic acid (PA) and p-toluenesulfonic acid (TSA). The EILs synthesized were characterized using thermogravimetry analyser (TGA) differential scanning calorimetry (DSC) analysis to determine the physical properties of the EILs. Based on the TGA analysis, ChCl (1): PA (3) obtained the highest thermal stability whereas, as for the DSC analysis, all synthesized EILs have a lower melting point than its pure component. Further evaluation on the best EIL for the desulfurization process was carried out in a photo-reactor under UV light in the presence of Cu-Fe/TiO2 photocatalyst and hydrogen peroxide (H2O2). Once the oxidation and extraction process were completed, the oil phase of the mixture was analyzed using high performance liquid chromatography (HPLC) to measure the sulfur removal efficiency. In terms of the desulfurization efficiency, the EIL of ChCl (1): TSA (2) showed a removal efficiency of about 99.07%.


Author(s):  
A.V. SYROESHKIN ◽  
E.V. USPENSKAYA ◽  
T.V. PLETENEVA ◽  
M.A. MOROZOVA ◽  
T.V. MAKSIMOVA ◽  
...  

Objective: Study the influence of the mechanical preparation methods (grinding, fluidization) of solid pharmaceutical substances (PS) and herbal raw material on their physicochemical properties and biological activities. Methods: Test substances and solvents-Lactose monohydrate (DFE Pharma, Germany). Sodium chloride, bendazol hydrochloride (all Sigma-Aldrich, USA) and herbal raw material (Callisia fragrans). The dispersity and native structure of pharmaceutical substances were analyzed by several methods: optical microscopy–Altami BIO 2 microscope (Russia); low angle laser light scattering (LALLS) method (Malvern Instruments, UK); Spirotox method–Quasichemical kinetic of cell transition of cellular biosensor Spirostomum ambiguum; Fourier-transform infrared spectroscopy–the analysis in the middle IR region was carried out using an IR Cary 630 Fourier spectrometer (Agilent Technologies, USA). The analysis of dried leaves of C. fragrans before and after mechanical activation was performed using Shimadzu EDX-7000 X-ray fluorescence spectrophotometer without mineralization (Shimadzu, Japan). Results: It was established that the mechanical change, such as dispersion and drying, alters the biological activity of PS and herbal raw materials. The observed increase in the influence of the dispersed substance on the biosensor S. ambiguum is quantitatively estimated from the values of the activation energy (obsEa), which turns to be valued 1,5 (P≤0,05) times more than for the native form substance. In the study of the dependence of the availability of chemical elements K, Ca, Zn on the degree of dispersion of herbal raw materials was established a quantitative 4-fold (P≤0,05) increase in the concentration of elements in mechano-activated raw materials. Conclusion: By the example of the biological model of Spirotox (single-celled biosensor S. ambiguum) and herbal raw materials obtained from C. fragrans, the increase of biological activity of PS at the dispersion of initial preparations was proved.


2007 ◽  
Vol 79 (11) ◽  
pp. 1887-1894 ◽  
Author(s):  
Alberto de Angelis ◽  
Paolo Pollesel ◽  
Daniele Molinari ◽  
Wallace O'Neal Parker ◽  
Alessandra Frattini ◽  
...  

This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), both molybdenum- and tungsten-based, in the oxidative desulfurization process of diesel. We are jointly developing a new oxidative desulfurization process, aimed at reducing the sulfur content in diesel to less than 10 ppm (parts per million) using in situ produced peroxides. In this new process, high-molecular-weight organosulfur compounds, such as 4,6-dimethyl-dibenzothiophene (DMDBT), difficult to be eliminated by conventional hydrodesulfurization, are oxidized to the corresponding sulfones and subsequently removed by adsorption. Molybdenum-based HPAs, with Keggin structure, proved to be the most active and selective catalysts for oxidizing DMDBT with on-stream lifetimes exceeding 1500 h time on stream (t.o.s.).


2020 ◽  
Vol 192 ◽  
pp. 02026
Author(s):  
Alexander Burdonov ◽  
Vyacheslav Barakhtenko ◽  
Konstantin Prokhorov ◽  
Yuri Novikov

This work presents research studies of alumina-containing estimates formed during the production of aluminum on electrolyzers with self-burning anodes during technological operations at PJSC RUSAL Bratsk. Material from the territory of the electrolysis workshop, with a mark of ± 0, is a mixture of finely dispersed powder, 2.5 mm in size (on average 62.78% by weight) with pieces of material from 0.5 to 6 cm in size. , 26% by weight). As a result of the work, the particle size and chemical-metallurgical properties of an alumina-containing estimate were studied. During the research, the content of valuable components and impurities in the sample of various classes was determined. In the process of mineralogical analysis, two phases were identified in the products: dark, black-gray and light, grayish-white. It is proved that these phases have significant differences in the chemical composition of the feed. Spectroscopic studies showed significant differences in the colorimetric characteristics of the raw materials, which is a fundamental factor for the use of photometric separation. Based on preliminary studies on the separation of alumina-containing estimates by photometric separation, the fundamental possibility of purifying contaminated material from technological impurities has been established.


1994 ◽  
Vol 12 (2-3) ◽  
pp. 177-190
Author(s):  
Charles L. McSpadden

With international refining industries facing a number of challenges in the near future, it seems clear that those who survive will be ones with the ability to turn serious problems into real opportunities. In the U.S. refining industry, challenges such as slow growth in product demand, increasing reliance on imported raw materials, and continued exposure to offshore exporting refineries will have critical effects on the ability of the industry to capitalize on available opportunities. Other challenges include the ability to tolerate continued declines in crude oil quality and the serious monetary questions related to compliance with environmental legislation, including air, soil, and water clean-up. This paper presents the challenges which the U.S. refining industry faces over the coming years, and seeks to address those issues which will impact the success or failure of the industry as a whole. The paper begins with a focus on the demand for U.S. petroleum products, encompassing brief historical data and forecasts of demand for the next few years. Closely related to demand is the subject of U.S. refinery operations, including product import and yield patterns. In this vein, the paper offers forecasts of crude runs to stills, as well as forecasts of capacity changes. Because profitability of U.S. refineries is affected by raw material costs, the paper next probes the possibilities resulting from world crude oil price fluctuations, considering the reemergence of Iraq as a market player. Forecasts of profit margins for U.S. refiners in 1998 are also offered. Turning to crude oil supplies and qualities, the paper examines the downward trend of U.S. crude oil production, providing a forecast of the decline by 1998. An associated trend, that of U.S. crude oil imports, is also evaluated, with a discussion of the origins of these imports included. The paper then presents a brief discussion of the principal recipient of Canadian crude oil exports, the U.S. Midwest (PADD II), encompassing statistics for refinery runs and deliveries of crudes. Volumes of Canadian crude exported to the region are also presented, as well as crude oil qualities in the region. Finally, heavy crude oil prices are examined because of the degradation of average crude oil qualities consumed by U.S. refiners. Spreads between light and heavy crudes are contemplated, with a forecast for the current-dollar WTI/Maya price spread provided.


Author(s):  
А.М. МЕДВЕДЕВ ◽  
К.Ш. САКИБАЕВ

Разработана технология получения СО2экстрактов с повышенным выходом СО2экстрактивных веществ после предварительной обработки зернового и орехового сырья электромагнитным полем низкой частоты (ЭМП НЧ) 28,36 Гц. Растительное сырье семена амаранта, винограда, расторопши пятнистой, ростки пшеницы, арахис, миндаль, ядра фисташковых и ореха грецкого подвергли измельчению в крупку размером 2 3 мм для дальнейшей обработки на вальцевом станке (d 0,2 мм). Измельченное сырье помещали в радиопрозрачный короб и трижды подвергали воздействию ЭМП НЧ по 20 мин с перерывом по 30 мин. Обработанное электромагнитным полем сырье заключили в сетчатую кассету и загрузили внутрь СО2экстрактора, работающего в докритическом режиме при давлении 6,5 МПа и температуре 22С. Продолжительность процесса экстракции сырья, ч: орехового 4,0 зернового 2,5. Установлено увеличение выхода биокомпонентов в экстракт из орехов и зерна, подвергнутых воздействию электромагнитных волн, по сравнению с контрольными образцами без обработки ЭМП НЧ. Выход СО2экстрактивных веществ из сырья до обработки и после обработки ЭМП НЧ составил, : арахис 8,0 и 14,1 орех грецкий 10,2 и 16,3 семена амаранта 4,7 и 5,4 семена винограда 6,0 и 6,5 соответственно. Концентрация фенольных веществ в экстрактах повысилась на 15, витаминов С и Р на 6,2 и 7,0 соответственно. Применение электромагнитного излучения НЧ привело к сокращению продолжительности экстракции из зернового и орехового сырья в 1,2 раза. A technology has been developed for producing CO2 extracts with an increased yield of CO2 extractives after preliminary processing of grain and nut raw materials with a low frequency electromagnetic field (LF EMF) of 28,36 Hz. Vegetable raw materials amaranth seeds, grapes, milk thistle, wheat germ, peanuts, almonds, pistachio kernels and walnuts kernels were crushed into a grain size of 2 3 mm for further processing on a roller machine (d 0,2 mm). The crushed raw material was placed in a radiotransparent box and exposed to LF EMF three times for 20 min with a break of 30 min. The raw material processed by the electromagnetic field was enclosed in a mesh cassette and loaded inside a CO2 extractor operating in a subcritical mode at a pressure of 6,5 MPa and a temperature of 22C. The duration of the extraction process of raw materials, h: nut 4,0 grain 2,5. An increase in the yield of biocomponents in the extract from nuts and grains exposed to electromagnetic waves was established compared with the control samples without processing the LF EMF. The yield of СО2 extractive substances from the raw materials before and after the treatment of LF EMF was, : peanuts 8,0 and 14,1 walnut 10,2 and 16,3 amaranth seeds 4,7 and 5,4 grape seeds 6,0 and 6,5, respectively. The concentration of phenolic substances in the extracts increased by 15, vitamins C and P by 6,2 and 7,0, respectively. The use of electromagnetic radiation of low frequency led to a reduction in the duration of extraction from grain and nut raw materials by 1,2 times.


2018 ◽  
Vol 26 (4(130)) ◽  
pp. 59-66
Author(s):  
Erhan Kenan Çeven ◽  
Gizem Karakan Günaydin

Recently there have been new trends in fancy yarns in order to meet consumer demands for drapery, decorative and outwear fabrics. Macaroni yarns are a promising group of fancy yarn which allows new yarn designs with different raw materials at different yarn counts. In the study, supreme knitted fabrics were produced with macaroni yarns of different raw materials (polyester, acyclic, cotton) at different yarn counts (Nm 2/1, Nm 2.5/1, Nm 3.3/1, Nm 4/1 and Nm 4.5/1). Completely randomised one-factor analysis of variance (ANOVA) was used for determination of the statistical significance of the fabric type on selected physical properties of knitted macaroni fabrics in terms of fabric weight (g/m2), dimensional change (%) in the wale and course direction, abrasion resistance, and air permeability properties before and after the washing process. According to the results of the statistical analyses performed using the experimental values obtained from the tests, we determined that the fabric weights (g/m2), dimensional changes (%) in the wale and course direction, abrasion resistance and air permeability properties before and after washing were significantly influenced by the macaroni yarn’s structural parameters (such as the yarn count and raw material comprising it).


2013 ◽  
Vol 781-784 ◽  
pp. 869-874 ◽  
Author(s):  
He Ping Tan ◽  
Huai Ping Li ◽  
Chi Guan ◽  
Hang Song ◽  
Yang Xu ◽  
...  

A simple and clean way of extraction of natural essence from green tea leaf by supercritical CO2 was developed. The optimum extraction conditions to produce the high-quailty natural essence were found: loading about 100g/L, operating at 5000 psi and 50 °C, and separation kettle temperature 75 °C, static extraction three times with 40 min every time, the yield of natural essence was 0.5%. The product was analyzed by gas chromatography-mass spectrometry (GC-MS) show that dimethylsulfide was the characteristic aroma components of the natural essence with more than 50 kinds of alcohols, ketones, aldehydes, ethers and esters etc.. There were only little other biochemical composition of raw material and 0.4% caffeine in the product detected by high-performance liquid chromatography (HPLC), and the biochemical composition in the raw material were almost no loss before and after extracted by supercritical CO2, it indicated that the specificity of the method for extraction tea natural essence is very strong, and propitious to improve the secondary utilization of the tea raw materials.


Author(s):  
Waqas Ahmad

This chapter describes the occurrence of organosulfur compounds in petroleum, their detrimental effects and various techniques for removal of these compounds. The sole commercial desulfurization process i.e. HDS is broadly discussed in terms of reaction conditions, different types of catalysts used, reactor design and mechanistic pathways in the process. The shortcomings of HDS and needs for developing new desulfurization techniques is also described. Various newly developed research techniques for desulfurization are also discussed with their technical backgrounds, commercial overview, advantages and shortcomings in the light of literature reports. These techniques include, Adsorptive desulfurization, Bio-desulfurization, Precipitative desulfurization, and Oxidative desulfurization with its sub types like ODS using H2O2- Polyoxometalates (POM), ODS with Ionic liquids, Photo-oxidative desulphurization and Ultrasound Assisted ODS.


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