-
Date submitted2023-10-22
-
Date accepted2024-03-05
-
Date published2024-08-26
The mechanism and thermodynamics of ethyl alcohol sorption process on activated petroleum coke
The low-quality petcoke does not find qualified application and is stockpiled at refineries or used as solid fuel. One of the promising ways to use low-quality petroleum coke is its physical or chemical activation in order to obtain a highly porous carbon material that can be used as a catalyst carrier, adsorbent, base for electrodes, etc. The possibility of using petroleum coke to produce sorbent for organic compounds was studied. The activated petroleum cake was obtained by chemical activation with KOH, a specific surface area is 1218 m2/g. Sorption of ethyl alcohol was studied at temperatures 285, 293 and 300 K. It is a physical process proceeding mainly in pores of activated petroleum coke, also sorption can be described as a reversible exothermic process. The effective Gibbs energy at a temperature of 293 K is –12.74 kJ/mol, the heat of sorption is –26.07 kJ/mol. The obtained data confirm that porous carbon material obtained from petroleum coke can be used as sorbent for ethanol at room temperature. For example, for adsorption of bioethanol from the effluent of the fermentation process or for purification of wastewater from organic compounds.
-
Date submitted2023-05-17
-
Date accepted2023-08-17
-
Date published2023-10-27
Scientific and technical substantiation of the possibility for the organization of needle coke production in Russia
Russia is one of the world's leading steel producers, while about 33 % of production comes from the scrap remelted in arc steelmaking furnaces. The graphitized electrodes of SHP and UHP grades, mainly consisting of needle coke, are used for high current loads and temperatures in furnaces. USA, Japan, Korea, and China are focused on needle coke production, where coal (tar and pitch) and petroleum (decantoil), by-products of metallurgical factories and oil refineries, are used as raw materials. Russia's annual demand for needle coke is approximately 100 thousand tons, but all of it is covered by imports. Russia's raw material potential, established by the authors of the article, is more than 5 million tons per year and includes decantoil, coal tar and pitch, and heavy pyrolysis tar. The results of obtaining needle coke from decantoil and heavy pyrolysis tar are given below. The prototypes of needle coke were produced on specially designed delayed coking laboratory units (loading up to 0.25 and 80 kg). Raw materials were modified according to the original technology of Saint Petersburg Mining University, the convergence of target properties of which is confirmed by the results of quality analysis of the obtained needle coke, including after 100-fold scaling. The electrodes were molded from the obtained coke. After standardized stages of firing, mechanical processing and graphitization at 2,800-3,000 °C, the coefficient of linear thermal expansion was less than 1 × 10–6 К–1, and the value of specific electrical resistance was 7.1-7.4 μOhm, which proves that the obtained carbon material corresponds in quality to Japanese analogues and Super Premium needle coke.
-
Date submitted2019-04-03
-
Date accepted2022-12-02
-
Date published2020-02-25
Influence of parameters of delayed asphalt coking process on yield and quality of liquid and solid-phase products
Paper studies the effect of excess pressure during delayed coking of asphalt, obtained by propane deasphaltization of tar, on yield and physical and chemical properties of hydrocarbon fuels' components and solid-phase product – petroleum coke. Asphalt was coked at a temperature of 500 °C and excess pressure of 0.15-0.35 MPa in a laboratory unit for delayed coking of periodic action. Physical and chemical properties of raw materials and components of light (gasoline), medium (light gasoil), and heavy (heavy gasoil) distillates obtained during experimental study were determined: density, viscosity, coking ability, sulfur content, iodine number, pour points, flash points, fluidity loss and fractional composition. Quantitative group hydrocarbon and microelement compositions and properties of obtained samples of petroleum coke (humidity, ash content, volatiles' yield, sulfur content, etc.) were also studied. Comparative assessment of their quality is given in accordance with requirements of GOST 22898-78 “Low-sulfur petroleum coke. Specifications”. In addition, patterns of changes in excess coking pressure on yield and quality indicators of distillate products and petroleum coke were revealed. With an increase in excess pressure of coking process from 0.15 to 0.35 MPa, content of paraffin-naphthenic hydrocarbons in light and heavy gasoils of delayed coking decreases. Common pattern in asphalt coking is an increase in yield of coke and hydrocarbon gas with an increase in excess pressure from 0.15 to 0.35 MPa.
-
Date submitted2015-12-08
-
Date accepted2016-02-02
-
Date published2016-12-23
Effect of chemical composition and quality of heavy Yarega oil on selection of appropriate processing technology
- Authors:
- N. K. Kondrasheva
- Anchita Khorkhe
The paper explores physical and chemical properties and composition of heavy oil from Yarega field and its vacuum residue, i.e. the tar. The capillary chromatography and gas chromatography-mass spectrometry were used to identify specific group hydrocarbon composition of heavy Yarega oil and components extracted therefrom, which has proven its belonging to highly resinous sulfurous naphthenic and aromatic oils. Based on the comparative analysis of composition and quality of feedstock a possibility has been assessed to produce a high-quality needle coke with low content of sulphur and metals from the heavy oil of Yarega field and its vacuum residue. An integrated process flow diagram for heavy Yarega oil refinement has been proposed, including preliminary deasphalting and demetallization, hydrotreatment, delayed coking and thermodestructive processes or gasification.
-
Date submitted2015-10-19
-
Date accepted2015-12-20
-
Date published2016-08-22
Changes in thermal plasticity of low grade coals during selective extraction of metals
- Authors:
- V. Yu. Bazhin
As the world oil market tends to be highly volatile, the coal becomes a primary source of organic raw materials for chemical and metallurgical industries. Fossil coals can accumulate high amounts of elements and mixtures quite often reaching commercially valuable concentrations. Reserves of scandium and other rare elements in coal deposits in Siberia alone are sufficient to satisfy the expected global demand for several decades. This study is intended to solve complex tasks associated with extraction of metal oxides using the developed enrichment method to ensure the required thermal plasticity determining the quality and properties of metallurgical coke. Laboratory experiments have been conducted for the enrichment of high-ash coals containing the highest concentrations of metals. Thermal plasticity values have been determined with the help of Gieseler plastometer . Using modern technologies and equipment individual deposits can be turned into profitable production of enriched coking coals with concurrent extraction of rare metals. It has been proven that the highest commercial potential lies with the extraction of scandium and some other rare metals in the form of oxides from the coal.