The catalytic activity of the binary composite catalysts of Fe2O3-CoO/CaA and Fe2O3-CoO/ZSM-5 was studied. They were obtained by impregnation of CaA and ZSM-5 zeolites with aqueous solutions of sulfates of iron (FeSO4·7H2O) and cobalt (CoSO4·7H2O). The total metal content was no more than 5%. Then, oxidizing burning at 720 °C for 60 min was performed to produce the metal oxides. It was found that the obtained Fe-Co/CaA catalyst contains iron and cobalt as CoFe2O4 compound, and the Fe-Co/ZSM-5 catalyst includes CoFe2O4 and CoFe. The phase composition of the obtained catalysts was detected by the X-ray diffraction analysis. The surface morphology was investigated by the electron microscopy. The elemental composition of the obtained catalysts was determined by energy dispersive spectroscopy with mapping and inductively coupled plasma atomic emission spectroscopy. The atomic absorption analysis by the IR-spectroscopy showed the shifts of absorption bands in the infrared spectra of the pure zeolites and with added Fe and Co. The catalytic hydrogenation of anthracene was performed to determine the catalytic properties of the obtained catalysts. It is one of the most common model compounds applied to investigate the efficiency of catalytic systems. The result of hydrogenation found that conversion of anthracene at 400 °C, initial pressure of 6 MPa and duration of 60 min using the Fe-Co/CaA catalytic system equaled to ~87%. However, hydrogenation products equaled to ~84%. Anthracene conversion using the Fe-Co/ZSM-5 catalytic system and the same conditions was ~91%; among them, hydrogenated derivatives were ~71%. The proposed method is characterized by its simple execution. The obtained catalysts are be slightly inferior to platinum and rhodium catalysts in the catalytic activity.
In this study, the characteristics of coal sorbents obtained by the activation of coke fines in an atmosphere of a mixture of gases CO2 and H2O were studied. The experiment was conducted at various temperatures (700–900 °C), activation time (60–180 min), and constant CO2 supply rate (0.5 L/min). The main parameters such as tinder, ash content, bulk density, sorption capacity, total pore volume, and specific surface area were analyzed to assess the efficiency of the process. The results showed that samples of sorbents obtained at a temperature of 800 °C and an activation time of 120 min have the highest sorption capacity for iodine (up to 64.77%). The specific surface area of the obtained carbon sorbents was ~432.6 m2/g. It was found that an increase in temperature to 900 °C leads to a decrease in sorption characteristics, which may be due to partial destruction of the porous structure of the material. It was also found that the duration of activation contributes to an increase in burn-off and ash content, which had an effect on sorption properties. Based on the data obtained, optimal conditions for the production of carbon sorbents have been established and a process model has been developed.
The possibility of obtaining effective coal sorbents from a low-liquid product of coke chemical production—coke fines—has been studied. To obtain a coal sorbent, coke fines with a size of ≤10 mm were crushed and sieved to obtain a fraction of 2–5 mm. The resulting fraction was activated in a specially designed reactor at 850 °C with steam treatment. Activation was carried out at different durations of the process: 60, 90, and 120 min. It was found that the sample obtained with a process duration of 120 min has the best indicator for the ability to remove phenol from aqueous solutions (74.94 mg/g) and methylene blue (145 mg/g). When cleaning tap water with the resulting carbon sorbent, there is a decrease in the content of calcium, sulfates, and bicarbonate and a decrease in total mineralization. Obtained activated carbon was studied by scanning electron microscopy, low-temperature nitrogen adsorption (BET), and FTIR spectroscopy. It was found that the resulting activated carbon has a porous structure consisting of meso- and macropores, and the specific surface value was ~301 m2/g. The presence of high-intensity absorption bands corresponding to acid functional groups has also been established.
Medium-temperature pitch was obtained by vacuum distillation of coal tar from the Qarmet coke chemical production. To determine the composition of the organic constituent of the Qarmet coal tar, the component composition was analyzed via gas–liquid chromatography (GLC) methods. The analysis of the component composition of the organic component of coal tar showed that the content of naphthalene and its derivatives is 37.57%, acenaphthene—2.10%, dibenzofurane—3.60%, fluorene—4.63%, phenanthrene—8.63%, anthracene—2.29%, fluoranthene—4.56%, and pyrene—2.84%. It was found that in the obtained pitch sample, indicators such as the content of insoluble in toluene (41.86%), the softening temperature (85–91 °C), and the yield of volatile substances (1.5%) are more consistent with the standards for electrode pitch grade “V”. The composition of fractions in baking soda, soluble in toluene and quinoline, has been established. In the fractions of pitch soluble in toluene, 11 components were identified, the main of which re fluoranthene (11.71%), pyrene (10.13%), phenanthrene (7.31%), and benzopyrene (4.84%). Thus, based on the analyses carried out, it was found that the Qarmet resin is suitable for obtaining a V-grade electrode pitch, which can be used in the aluminum industry.
This paper studies the dependence of the specific heat capacity (Cp) of activated carbon obtained by the activation of coke fines on temperature (T, K) and the dependence of electrical resistance (R, Om) on temperature (T, K). In the course of the work, it was found that in the temperature range of 298.15–448 K on the curve of dependence Cp − f(T) at 323 K there is a jump in heat capacity, associated with a phase transition of the second kind. Measurements of the temperature dependence of electrical resistance on temperature were also carried out, which showed that activated carbon in the temperature range of 293–343 K exhibits metallic conductivity, turning into a semiconductor in the temperature range of 343–463 K. The calculation of the band gap showed that the resulting activated carbon is a semiconductor with a moderately narrow band gap. The satisfactory agreement of the phase transition temperatures on the curves of the temperature dependences of the heat capacity on temperature (323 K) and on the curves of the dependences of electrical resistance and the relative permittivity on temperature (343 K) indicates the nature of this phase transition, i.e., at a temperature of 323 K, the change in heat capacity is associated with the transition from semiconductor conductivity to metallic.
The research topic is the influence of preliminary ultrasonic treatment of coal tar at ArcelorMittal Temirtau on the individual composition of the products