Solid Fuel Chemistry最新文献

Adsorption has numerous advantages over other wastewater treatment methods. Since it has the best sorption qualities and is a flexible adsorbent, biosorbent derived from biochar has been employed extensively to remove chemical species from their aqueous solutions. Hemidesmus Indicus, a new biosorbent, was used to study the biosorption of the anionic dye Congo red from aqueous solution. Variations in solution initial dye concentration, contact time, and temperature were used to determine the ideal sorption conditions. In batch adsorption investigations, Hemidesmus indices efficiency in eliminating Congo red dye as a bio adsorbent is investigated in this work, along with factors including dosage, pH, and beginning dye concentration. Congo red dye was shown to be more readily absorbed by surfaces treated with KOH compound, UV-visible adsorption spectroscopy is used to measure dye decolourization, and Analyzes surface morphology changes like pore structure, roughness, surface deposition or blocked pores are determined by FTIR and SEM with EDAX are used to examine the adsorbent’s altered surface properties. Congo red dye was shown to be more readily absorbed by surfaces treated with KOH compound, leading to elimination percentages of 51, 73.4, 54.26, 52.36, and 42.54%. Adsorption efficiency is evaluated using mathematical evaluation such as the Adams-Bohart and Yoon Nelson model; the equilibrium isotherm data model’s adsorption-derived R² values are 83.26, 91.5.67 and 74.51.

Here, the organic concentration in wastewater is reduced using a Digital Baffle Batch Reactor (DBBR) for new process electro catalytic and electro coagulation process (EC&ECP), which is based on an anatase titanium oxide (anatase-TiO₂). The work deals with the treatment of simulated reactive blue wastewater (RBWW) through electro of coagulation and oxidation in a batch electro-catalytic reactor by means of aluminum and iron as anode and cathode resources correspondingly. All these data based on the results obtained from characterization such as SEM, XRD and FTIR. Belongings of operating issues for example titanium dioxide (15–45 ppm), pH (3–9), and time (10–50 min) and (5–20 ppm) concentration of reactive blue on the organic removal (OR) were deliberate. The consequences revealed that titanium dioxide concentration has the chief result on the competence of OR confirming that the hybrid was ruled through reaction circumstances in the RBWW solution. Parametric optimization was approved out by means of response surface methodology combined with Box Behnken Design toward make the most of the OR. Below enhanced working circumstances, the organic elimination was found to be 98.9%. The new reactor design (DBBR) provided the reactivity the anatase-TiO₂ made using new process the electro catalytic and electro coagulation (EC&ECP) and achieve a high organic removal rate, resulting in clean water. Additionally, the new reactor, material, and EC&ECP process have not all been met in a single process, and this is thought to be the first investigation in this field.

To address the severe issue of spontaneous combustion in residual coal within gob areas under gob-side entry retaining conditions, this study investigates fire prevention strategies during coal mining operations at the 22523 working face of Halaigou Coal Mine through integrated field measurements, experimental analyses, and numerical simulations. The findings reveal that the spontaneous combustion risk zones in gob-side entry retaining faces can be categorized into two distinct regions: the rear section of the working face and the gob-side entry area. The hazard distribution behind the working face demonstrates similarity to conventional “U”-type ventilation patterns, while the combustion risk in the entry-retained side primarily arises from the combined effects of leakage through flexible formwork walls, residual coal distribution patterns, and inherent coal oxidation characteristics. Progressive analysis demonstrates that the maximum oxidation zone and peak temperature locus migrate from the return air side toward the gob-side entry area with advancing face progression. Comparative evaluation of nitrogen injection strategies (single-point, uniform multi-point, and self-regulating multi-point configurations) demonstrates that the self-regulating nitrogen injection system achieves superior fire suppression efficacy compared to single-point injection while reducing nitrogen consumption by 43.3% relative to uniform multi-point injection. These empirical findings establish the technical and economic viability of the self-regulating injection protocol for practical implementation at the 22523 working face.

To investigate the dispersion and complex propagation of toxic and hazardous hot gas clouds in mine ventilation networks following gas explosions, this study examines the Tunlan Mine “2.22” gas explosion accident. A simulation model of the Tunlan Mine was established, and gas explosion experiments were conducted to determine the initial concentration and temperature distribution of the gas cloud post-explosion. The TF1M3D simulation platform was utilized to model the post-explosion migration and spread of CO-deficient hot airflow under various ventilation conditions. The simulation revealed that when the Liangzhuang return air shaft fan failed for 30 min, CO-deficient hot airflow dispersed throughout the mine under the influence of other ventilation fans and residual explosion heat. After ventilation was restored, the hazardous airflow was completely expelled from the mine within 30 min. The simulation demonstrated that the hazardous airflow changed direction twice before and after the restoration of the Liangzhuang return air shaft fan, affecting working faces 12 403 and 12 405 twice and exacerbating the disaster’s impact and spread. The influence of self-rescuer time limits on personnel evacuation was analyzed in relation to the disaster airflow propagation process. The simulated disaster propagation patterns aligned with actual events. Drawing lessons from the accident, ventilation control strategies to facilitate personnel escape and mitigate disaster spread are proposed, providing reference for emergency ventilation control in mine gas explosions.

Macroporous carbon materials (macro-PCMs) were obtained using a matrix synthesis approach which consists in the deposition of pyrolytic carbon (PC) on a matrix of P803 carbon black (CB) during its high-temperature treatment in hydrocarbon medium. The microstructure, morphology, and porous structure of synthesized macro-PCMs were studied using a set of methods, such as transmission and scanning electron microscopy, X-ray diffraction, Raman spectroscopy, low-temperature nitrogen adsorption, mercury porosimetry, and helium pycnometry. It was shown that PC is deposited on the CB matrix surface both in the form of ordered graphene layers and as wedge-shaped particles. Two stages of the macro-PCM formation can be distinguished. At the first stage (α < 0.66 g of PC per g of CB), the most accessible macropores with sizes of >100 nm are predominantly filled with PC and then, at the second stage (α > 0.66 g of PC per g of CB), pores with sizes of <100 nm are also filled. A decrease in the specific pore volume V_>100 from 0.48 to 0.26 cm³/g_CB occurs with volumetric filling of large macropores (>100 nm) between aggregates, while the PC deposition at α > 0.66 g/g leads to a decrease in V_<100 to 0.077 cm³/g_CB and to an almost constant value for V_>100.

When coal resources enter deep mining, the coal body is exposed to a complex geological condition characterized by “high ground stress”, “high osmotic pressure” and “high temperature”. Under such geological conditions, the permeability evolution law of the coal body is determined by the coexistence of multi-phase and multi-field coupling. Moreover, the permeability of the coal body directly impacts the safety of coal mining operations. Thermodynamic coupling tests were conducted on coking coal samples. The scanning electron microscope and high-pressure adsorption instrument were employed to characterize the pore structure and adsorption capacity on the coal surface. Subsequently, the changes in the coal pore structure and gas displacement efficiency before and after the thermodynamic coupling treatment were compared and analyzed. The results demonstrated that, under thermodynamic coupling, the adsorption of CH₄ in the coal rises with the increase in pressure. However, as the temperature increases, the adsorption of CH₄ in the coal exhibits an opposite tendency. With the growth of injection pressure, the replacement ratio of CH₄ decreases linearly. Likewise, with the elevation of temperature, the CH₄ replacement ratio also diminishes. After the thermodynamic coupling, the pore structure of the coal sample is well-developed and the porosity is enhanced. The research findings can offer a theoretical foundation and technical guidance for the study of multi-field coupled gas migration and coal seam gas treatment.

The peculiarities of changes in the composition of SS grade coal prone to spontaneous combustion after its treatment in gas environments of various chemical activities (nitrogen, air, and carbon dioxide) were investigated. The effect of gases on changes in the chemical composition of the coal surface and the adsorption capacity to oxygen during low-temperature oxidation of coal in the air was established. The EPR-spectroscopic data indicated the recombination of free radicals at the initial stages of coal oxidation followed by an intensification of their formation when coal samples were exposed to air. An analysis of changes in the rate of oxygen absorption and the composition of the gas phase indicated the highest sorption activity to oxygen of a coal sample treated in an inert nitrogen environment. The crushing of coal in an atmosphere of air led to the primary oxidation of the native outer surface and a decrease in the sorption capacity to oxygen at the initial stage of its determination. The adsorption of carbon dioxide on an accessible coal surface was accompanied by a transformation of its functional composition and, thereby, a slowdown at the initial stages of oxidation.

To develop a sustainable approach for coal pitch utilization, oxidation of commercial coal pitch in aqueous NaOCl solution was investigated. Effects of feeding methods, reaction temperature and time on coal pitch oxidation conversion rate were investigated. The maximum oxidation conversion rate was 17.4% at the optimized conditions of 50°C and 6 h, with multi-stage feeding method using 75–25–25 mL NaOCl solution. A mathematical regression model is developed to predict the oxidation conversion rate of coal pitch, which can accurately capture the reaction behavior observed in the experimental data (R² = 0.976). The oxidized pitch residue was characterized by FTIR, and the extracted products were analyzed by GC-MS. The results suggest that NaOCl oxidation is an effective treatment under mild conditions, obtaining value-added organic chemicals. Hydroxyls and carbonyls were introduced into the structure of the oxidized coal-pitch; 33 organic-compound products were detected, including value-added chemicals, i.e. naphthalene, phenanthrene, and anthraquinone. Thus, the aqueous NaOCl treatment exhibits a good potential to improve the economy of commercial coal pitch application.

The article presents the results of studies of the distribution of rhenium in black (dictyonema) shales of the Baltic basin in the Kaibolovo–Gostilitsy area located in the Leningrad oblast. Rhenium contents exceeding the levels of minimum industrial concentrations in known types of complex ores have been determined. The distribution of rhenium in the organic and mineral matter of black shales has been studied. The distribution of rhenium in the dictyonema shale formation over the area and in the section of the shale-bearing stratum and the conditions under which rhenium mineralization was formed are described. The rhenium resources in the dictyonema shales of the Russian part of the Baltic basin should be considered as a new unconventional source of this valuable strategic metal.

The distribution and kinetic analysis of catalytic hydrogenation products derived from preasphaltenes (PA) were examined. A kinetic model was developed using the lump kinetic method to simulate the hydrogenation of PA catalyzed by FeS and S. The study revealed that PA is directly converted into asphaltenes (AS) and oil, followed by the further hydrocracking of AS into oil and gas products. At higher temperatures, there is a noticeable regression of PA to char and AS back to PA. Increased temperature and longer reaction time were found to enhance the conversion of PA and the yield of oil and gas products. Under conditions of 400°C and 60 min, the hydrogenation of PA achieved a conversion rate of 75.92% with an oil and gas yield of 32.76%. The hydrogenation conversions from the model corresponded well with experimental data, and the activation energies ranged from 67 to 224 kJ · mol^–1.