Chemical Engineering Journal Advances最新文献

Gas hydrate crystallization is perspective and energy-efficient technology for gas mixtures processing, including natural gas. There were compared pressure-dropping and continuous gas hydrate crystallization methods for separation of gas mixture closed to natural gas. The studied mixture has been chosen similar to the natural gas composition: CH₄ (75.68 mol.%) - С₂H₆ (7.41 mol.%) - C₃H₈ (4.53 mol.%) - н-C₄H₁₀ (2.47 mol.%) - CO₂ (5.40 mol.%) - H₂S (1.39 mol.%) - N₂ (3.01 mol.%) - Xe (0.11 mol.%). Experiments were provided in the 4 L high pressure reactor, using water solution of SDS (0.20 wt.%). The experiment conditions were 280.15 K and pressure of 4.25 MPa. The components separation factors and recovery for two modes have been researched and compared for choosing more effective options. After comparing these characteristics, it was concluded that continuous process is more productive than pressure-dropping mode. At the stage cut (θ) of 0.9, the gas components total recovery (R) for the continuous mode have exceeded the total recovery for the pressure-dropping mode by 8.15 %, and at θ = 0.8, exceeded by 6.11 %. The recovery and separation factors have the highest values for H₂S, C₃H₈, Xe in the continuous mode: 97.62 %, 94.90 %, 84.98 % and 8.7, 10.53, 6.36, respectively. Thus, the choosing of the more effective stage cut depends on the aim of the process: the highest purity or the largest recovery.

Pakistan faces social and health issues due to the mismanagement of municipal solid waste (MSW) in urban and rural areas. Unhygienic conditions due to roadside disposal of MSW negatively affect society, aesthetics, economy, and tourism. This study aims to determine the potential of thermal energy-based MSW incineration technology for electricity generation and waste volume reduction in six major cities in Punjab, namely Lahore, Rawalpindi, Islamabad, Faisalabad, Gujranwala, and Sialkot. In this study, the heat content was calculated using the modified Dulong's equation for the calorific value (CV). Population, waste generation rate, waste characteristics, moisture content, and local public practices also affect energy potential and were considered in the calculations of electricity generation potential. Furthermore, three different sensitivity analysis trials of the power generation capacity were performed with various waste-to-energy (WtE) plant output efficiencies. The analysis of greenhouse gas (GHG) emissions from MSW incineration and CO₂ reduction was compared with existing local practices. For WtE potential, Lahore has an energy recovery of 552 kWh/ton of MSW. Carbon footprints can be reduced by incinerating waste rather than disposal through pollution-generating local practices, such as open burning. The study results showed that MSW handling in Punjab can be utilized for WtE generation, a potential alternative to fossil fuel combustion for sustainable energy solutions.

Due to the excessive consumption of fossil fuel resources and the emission of a substantial quantity of CO₂ into the environment, it is urgent to develop clean energy solutions. In order to reduce carbon emissions from the source, it is effective approach to convert CO₂ into various renewable energy fuels. Inspired by the photosynthesis of green plant, CO₂ is converted into clean fuel with the aid of catalysts. Regarding the separation and transfer of photogenerated charge carriers, and inadequate adsorption and activation of CO₂ on the surface of catalysts, the current semiconductors utilized in photocatalysis have low efficiency. As a result, the current efficiency of photocatalysts is far from meeting the need for practical industrial demands. MXene materials, for example Ti₃C₂T_x (9980 S cm⁻¹), have emerged as a promising candidate for CO₂ reduction due to the significant number of active sites for functional groups, high conductivity and low defects, large surface areas, and outstanding visible light photoelectronic properties. This review provides a critical overview of the recent progress regarding MXene as a co-catalyst in photocatalytic CO₂ reduction systems. We systemically explore the fundamental principles and reaction mechanisms associated with separating and transferring photogenerated charge carriers. Additionally, we investigate the basic properties of MXene as a co-catalyst in the context of CO₂ reduction. Furthermore, this review also elucidates the impacts of the microstructure of photocatalysts on enhancing photocatalytic performance. Finally, the challenges and opportunities in using MXene as a co-catalyst for CO₂ reduction have been presented to inspire further research in this field.

In polar environments, the presence of ice on the surfaces of ships and instruments can lead to equipment failure, an unstable center of gravity, and pose hazards to operators. To mitigate the damage caused by both icing and corrosion, this paper aims to investigate a corrosion-resistant photothermal deicing coating material. The coating matrix utilizes a low-viscosity epoxy resin system, while the additives include polypyrrole (PPy) with excellent photothermal conversion capability and corrosion resistance, along with graphene oxide (GO)-modified nano-silica. By carefully controlling the ratio, a composite coating is formulated with both anti-corrosion and photothermal deicing abilities under light conditions. The results demonstrate that under simulated sunlight irradiation, the surface temperature of the coating at different proportions can rise to over 80 ℃ within 10 min, with the highest temperature reaching 84.9 ℃. The optimal proportion of the coating remains unfrozen at -15 ℃, exhibiting an icing delay time of 710 s, and the frozen droplets melt within 5 s. Additionally, the coating exhibits excellent corrosion resistance, contributing to a more effective protection of metal surfaces. Therefore, this type of photothermal anticorrosive coating holds significant potential for widespread application in polar environments.

Carbon fibre reinforced polymers (CFRPs) are an attractive and versatile material, owing to their low weight and high mechanical stability, among other characteristics. This has led to a rapid increase in their use across many industries, particularly the aviation and automotive sectors. However, large quantities of waste are being generated when CFRPs reach their end-of-life (EoL) due to limited recycling and reuse pathways. To create a circular economy for CFRPs, alternative, high-value EoL pathways for recycled carbon fibres (rCFs) are needed. At present, very few studies investigate the activation of rCFs, particularly for applications as adsorbents. Developing on from the authors’ previous study, where rCFs were shown to be a promising precursor for the development of carbonaceous adsorbents, for applications in aqueous-phase, this work has focused on optimising the chemical activation procedure via a Box Behnken design-response surface methodology (BBD-RSM) approach, with an aim to maximise product yield and methylene blue adsorption capacity, using virgin carbon fibres (vCFs) as proof of concept. The optimum activated rCFs achieved an adsorption capacity of 454.55 mg/L; a significant increase of 715 % when compared to the previous study. While the optimum activated vCF counterpart achieved a maximum adsorption capacity 344.83 mg/L.

Reduce environmental impacts and guarantee a steady supply of critical chemicals by practising sustainable waste management and chemical production. By advancing circular economy ideas and decreasing dependency on finite resources, this research has the potential to alter the industrial landscape radically. The technological, economic, regulatory, and social barriers to waste material recovery and chemical production are explored in this paper. The key to resolving these issues is the identification of solutions that are both economically viable and environmentally benign. This paper introduces the sustainable Chemical Production and Waste Material Recovery Framework (CP&WMRF), which incorporates innovative recycling and upcycling methods, innovative chemical manufacturing processes, and the incorporation of digital technologies like artificial intelligence (AI) and machine learning (ML) to maximize the efficiency with which resources are employed. It is possible to reduce waste and energy use in the production of Interfaces with the help of CP&WMRF. Chemicals can be manufactured using sustainable feedstocks as an alternative to fossil fuels. The system standardizes how e-waste can be recycled and recovered metals and materials can be used. To prove the viability and efficiency of these methods, they require innovative simulation and modeling tools. The assessments help decision-makers understand the benefits and drawbacks of the proposed technologies in terms of their performance, environmental effect, and economic viability. When pitted against AI-ML, which achieved 94.2 %, CP&WMRF's 96.2 % result reveals a significant edge. AI-ML is less efficient, with a score of 93.8 %. The field of sustainability analysis, with a score of 95.2 %, is higher than AI-ML's decent lower score of 93.2 %. The impressive 97.5 % score of CP&WMRF in terms of resource efficiency substantially surpasses the 92.8 % score ascribed to AI-ML. The remarkable success of CP&WMRF in optimizing waste recovery, with a score of 98.7 %, higher than the 91.5 % associated with AI-ML. The present research establishes the framework for a revolutionary move toward circular and green chemistry by integrating innovative methods, all-encompassing applications, and rigorous simulation analysis.

Silicon-based lithium-ion battery negative electrodes represent one of graphite's most promising replacements. However, the enhanced capacity and unique Li⁺ storage method have raised the demands on the binder and other passive electrode components. For cycle stability, a sufficient carbonaceous matrix with silicon is needed. One of the most desirable anode materials for Li-ion batteries (LIBs) is Si, which has been noted for its exceptional volumetric and gravimetric qualities. Its affordability, abundance, and environmental safety stand out in particular. We assess the most recent improvements in the production of intercalation-type, conversion-type, and alloying-type anode materials in this work. After explaining the electrochemical reaction and failure, we reviewed several techniques for enhancing battery performance, including nanostructuring, alloying, building hierarchical structures, and employing the proper binders. Researchers will get the necessary information from this research work to conduct future research.

The present study compares the kinetics and thermodynamics of the pyrolysis process of coffee and tea waste with respect to their physicochemical properties to analyze their potential as an energy and carbon source. Coffee and tea waste exhibit a promising source as a biofuel that has gross calorific values of 22.7 MJ kg⁻¹ and 20.2 MJ kg⁻¹, with significant differences in the overall volatile conversion of 76 % and 65 %, and as final carbon with a yield of 22 % and 31 %, respectively. Kinetic analyses using isoconversional methods show a trend of activation energy and frequency factor with conversion for both samples, with a significant difference at a conversion beyond 0.6 due to the higher lignin content in coffee waste. The predicted master plots indicate complex pyrolysis kinetics for both samples. Furthermore, the reaction kinetics determined by the multivariate regression approach, assuming parallel independent reactions of the nth order applicable to all heating rates, provide the individual mass change and carbon yield of each reaction process that can be controlled using experimental conditions. Finally, the thermodynamic parameters indicate that the pyrolysis process of both coffee and tea waste is nonspontaneous and endothermic, and its reactivity increases with conversion.

In this study a 2D visualization technique is presented that is suitable for determining the optimal operational parameters of solid waste gasification depending on the intended use of the product. Steam gasification of different wastes (wheat straw, wood, municipal solid waste (MSW), polyethylene (PE), green waste) was modelled in Aspen Plus simulation software, validated with literature data and a MATLAB – Aspen Plus inter software connection was also created to minimize the possibility of errors when the raw material composition and other parameters are changed. Correlation was found between the simulation and literature data; therefore, the model was also suitable for evaluating the effects of process parameters (T = 650–1100 °C, steam rate = 0–1.5 kg/h) on gas composition, lower heating value and H₂/CO ratio. The model was also extended to a wide range of domestic waste types, making it possible to determine the optimal process parameters without performing a high number of time- and energy-intensive gasification experiments. Regarding the process parameters it was established that the temperature has a significant effect on the gasification reactions and shifts the chemical reactions towards hydrogen and carbon monoxide formation, but above 800 °C it has a limited effect on the gas composition, lower heating value and H₂/CO ratio. The increasing steam rate also facilitated the hydrogen and carbon monoxide formation, but above a certain ratio its effect was opposite due to the water-gas shift reaction and the shorter residence times. The obtained gases can be used for energy purposes or as raw material for Low-Temperature Fischer-Tropsch synthesis, or production of aldehyde, higher alcohol, acetic acid or even polycarbonate for which the optimal temperatures and steam rates were also determined.