Coke and Chemistry最新文献

The paper highlights the issues of thermal decomposition of aluminum chloride hexahydrate which is applied to the integrated technology of ash processing from the combustion of Ekibastuz coal. To solve this problem the possibility of using thermal decomposition of AlCl₃·6H₂O crystals in a static state and in a fluidized bed is considered. This approach allowed conducting a comparative assessment and selection of the most rational method for the thermal decomposition of ACH from a technological and economic point of view. It was found that under the conditions of thermal decomposition of ACH in a static state, its maximum decomposition to Al₂O₃ is achieved at a temperature of 400°C. The residual chlorine content in alumina is 1.09%, and aluminum in the form of AlCl₃ is 0.5% of the total aluminum content. At a temperature of 500°C, the residual chlorine content in alumina is 0.71%, and AlCl₃ is practically not detected. It was found that crystals of AlCl₃·6H₂O almost completely decompose in a fluidized bed at a temperature of 500°C (residual chlorine content 0.75%). In this case, the degree of decomposition of AlCl₃·6H₂O crystals was 87% at 300°C and 95% at 400°C. After calcining the samples obtained at 900°C, the residual chlorine content in them decreased to 0.27%, and after calcining at temperatures above 1000°C, no chlorine was detected in the samples at all. The specific surface area of alumina obtained after thermal decomposition at 400°C was 169.6 m²/g. After additional roasting of the sample at a temperature of 1200°C, the specific surface area of alumina decreased to 7.8 m²/g.

Abstract

The possibility of extracting vanadium from various carbon materials (petroleum coke, bitumen, fuel-oil ash and slag, ash from foundry graphite, black shale, and lignite) is investigated. Systems for producing vanadium slag from ash and from titanomagnetite ore are compared. The two types of slag are compared in terms of phase composition, chemical composition, and content of soluble forms of vanadium. In experimental melts, a vanadium alloy and vanadium slag are obtained. The potential for extracting vanadium from carbon materials is demonstrated.

The objective of this paper is to learn the possibilities of using biofuel to ensure the heating of indurating machines and assess its impact on the volume of emissions. The main source of fuel was sunflower husk, which can be used in pellet production by the following means: the firing and utilization of fume laden gas as a heat carrier during drying of blend materials and the gasification and utilization of syngas as the fuel in order to heat the indurating machines while thermally treating the pellets. Mathematical simulation was adopted as the research methodology. The results reveal that using biofuel to heat indurating machines during the pelletizing process is technologically feasible. However, there are numerous constraints that are mainly related to environmental issues and logistics. In the course of firing, husk generates additional solid waste and sulfur oxide, although, from the perspective of ESG statistics, it leads to a reduction in the carbon footprint of the end products. Issues related to the handling and storage of biofuel are caused by its aggregate state (solid), low bulk weight, and relatively low calorific value. The abovementioned parameters make biofuel a less favorable source of fuel when compared with natural gas. The aspects of biofuel application shall be considered when planning “energy transition” activities, since they affect economic viability, along with the environment of industrial regions (and the quality of life of inhabitants as well).

The combustion behaviors of semi-coke, anthracite, bituminous coal and their blends were studied using a thermogravimetric analyzer. Compared with anthracite, the experiments showed that semi-coke had low ignition temperature, good comprehensive combustion characteristics and high burnout rate. In compound samples, with the increase of SC1 semi-coke content, the ignition temperature of BC bituminous coal, IC mixed sample and SC1 compound samples gradually decreased, and the comprehensive combustion characteristic index S increased, and the TG curves of the compound samples moved to the low temperature. In the BC and IC compound sample, the ignition temperature and comprehensive combustion characteristic index of compound samples also improved with the addition of SC2 semi-coke and SC3 semi-coke. Furthermore, By means of the universal integral method, the results indicated that the shrinkage cylinder model of phase boundary reaction was the most probable mechanism function of semi-coke, anthracite and bituminous coal combustion. The kinetic parameters of the samples are obtained that the activation energy of semi-coke was lower than that of anthracite. In summary, mixing semi-coke with pulverized coal into blast furnace was beneficial to fuel combustion.

An increasing number of coking enterprises are challenged by excessive sulfur content in their crude benzene products, which hinders sales and revenue. In this work, microcrystalline adsorbent was used to remove carbon disulfide and thiophene in crude benzene. BET, XRD, XRF and SEM characterization showed that the microcrystalline adsorbent has a large specific surface area, high crystallinity morphology, Si/Al ratio and regeneration stability. By investigating the effects of adsorption time, temperature, adsorbent dosage and regeneration times on the desulfurization performance of microcrystalline adsorbent W1, it was found that the desulfurization effect was mainly affected by time and temperature. When the experimental conditions at 20°C, 7 h, the amount of adsorbent was 4.5 g, the volume of crude benzene was 10 mL, resulting in desulfurization rate of 67% for thiophene, 52% for carbon disulfide, and 62% for total desulfurization, approximately 26% for crude benzene loss rate. The overall desulfurization rate remained stable around 55% after three regenerations, while the rate for rude benzene loss increased to roughly 30%. The results indicate that the microcrystalline adsorbent exhibits significant potential for desulfurization of crude benzene, providing valuable guidance and reference for coking enterprises.