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Molecules (Basel, Switzerland) Apr 2024This comprehensive review addresses the need for sustainable and efficient energy storage technologies against escalating global energy demand and environmental... (Review)
Review
This comprehensive review addresses the need for sustainable and efficient energy storage technologies against escalating global energy demand and environmental concerns. It explores the innovative utilization of waste materials from oil refineries and coal processing industries as precursors for carbon-based electrodes in next-generation energy storage systems, including batteries and supercapacitors. These waste-derived carbon materials, such as semi-coke, coal gasification fine ash, coal tar pitch, petroleum coke, and petroleum vacuum residue, offer a promising alternative to conventional electrode materials. They present an optimal balance of high carbon content and enhanced electrochemical properties while promoting environmental sustainability through effectively repurposing waste materials from coal and hydrocarbon industries. This review systematically examines recent advancements in fabricating and applying waste-derived carbon-based electrodes. It delves into the methodologies for converting industrial by-products into high-quality carbon electrodes, with a particular emphasis on carbonization and activation processes tailored to enhance the electrochemical performance of the derived materials. Key findings indicate that while higher carbonization temperatures may impede the development of a porous structure, using KOH as an activating agent has proven effective in developing mesoporous structures conducive to ion transport and storage. Moreover, incorporating heteroatom doping (with elements such as sulfur, potassium, and nitrogen) has shown promise in enhancing surface interactions and facilitating the diffusion process through increased availability of active sites, thereby demonstrating the potential for improved storage capabilities. The electrochemical performance of these waste-derived carbon materials is evaluated across various configurations and electrolytes. Challenges and future directions are identified, highlighting the need for a deeper understanding of the microstructural characteristics that influence electrochemical performance and advocating for interdisciplinary research to achieve precise control over material properties. This review contributes to advancing electrode material technology and promotes environmental sustainability by repurposing industrial waste into valuable resources for energy storage. It underscores the potential of waste-derived carbon materials in sustainably meeting global energy storage demands.
PubMed: 38731570
DOI: 10.3390/molecules29092081 -
Molecules (Basel, Switzerland) Apr 2024The mechanism of ammonia formation during the pyrolysis of proteins in biomass is currently unclear. To further investigate this issue, this study employed the AMS...
The mechanism of ammonia formation during the pyrolysis of proteins in biomass is currently unclear. To further investigate this issue, this study employed the AMS 2023.104 software to select proteins (actual proteins) as the model compounds and the amino acids contained within them (assembled amino acids) as the comparative models. ReaxFF molecular dynamics simulations were conducted to explore the nitrogen transformation and NH generation mechanisms in three-phase products (char, tar, and gas) during protein pyrolysis. The research results revealed several key findings. Regardless of whether the model compounds are actual proteins or assembled amino acids, NH is the primary nitrogen-containing product during pyrolysis. However, as the temperature rises to higher levels, such as 2000 K and 2500 K, the amount of NH decreases significantly in the later stages of pyrolysis, indicating that it is being converted into other nitrogen-bearing species, such as HCN and N. Simultaneously, we also observed significant differences between the pyrolysis processes of actual proteins and assembled amino acids. Notably, at 2000 K, the amount of NH generated from the pyrolysis of assembled amino acids was twice that of actual proteins. This discrepancy mainly stems from the inherent structural differences between proteins and amino acids. In proteins, nitrogen is predominantly present in a network-like structure (NH-N), which shields it from direct external exposure, thus requiring more energy for nitrogen to participate in pyrolysis reactions, making it more difficult for NH to form. Conversely, assembled amino acids can release NH through a simpler deamination process, leading to a significant increase in NH production during their pyrolysis.
Topics: Ammonia; Pyrolysis; Molecular Dynamics Simulation; Proteins; Amino Acids; Nitrogen
PubMed: 38731506
DOI: 10.3390/molecules29092016 -
ACS Omega Apr 2024The efficient and clean utilization of urban waste can substitute for partial fossil fuels and reduce total carbon emissions. Fuel combustion is divided into three...
The efficient and clean utilization of urban waste can substitute for partial fossil fuels and reduce total carbon emissions. Fuel combustion is divided into three stages. Before the fire, the fuel is put into the furnace to reach the preparation stage of the fire temperature, the combustion stage takes place after the ignition temperature is reached, and finally, the combustion is completed. This article employs numerical simulation methods to comprehensively study the effects of various factors on the combustion characteristics of waste in a mechanical grate incinerator, including the inclination angle of the front arch, fuel properties, height of the front and rear arches, air distribution methods, and speed of the grate chain rotation. The results indicate that when the rear arch angle is set at 25°, the airflow distribution within the furnace is uniform and the high-temperature flue gas exhibits an ideal "L" shaped flow, achieving favorable characteristics of airflow distribution inside the furnace. With this structure, the airflow from the rear arch can adequately penetrate deep into the front arch area, thereby forming an efficient T-shaped combustion flame.
PubMed: 38617677
DOI: 10.1021/acsomega.3c09554 -
Polymers Apr 2024Mesophase pitch is usually prepared by radical polymerization or catalytic polymerization from coal tar, petroleum, and aromatic compounds, and the catalytic synthesis...
Mesophase pitch is usually prepared by radical polymerization or catalytic polymerization from coal tar, petroleum, and aromatic compounds, and the catalytic synthesis of mesophase pitch from pure aromatic compounds is more controllable in the preparation of high-quality mesophase pitch. However, the corrosive and highly toxic nature of the catalyst has limited the further development of this method. In this study, mesophase pitch was synthetized using ethylene tar and naphthalene as raw materials and boron trifluoride diethyl etherate as a catalyst. The effect of the catalytic reaction on the structure and properties of the mesophase pitch was investigated. The results show that naphthalene plays an important role in the mesophase content and reaction pressure (from above 6 MPa to 2.35 MPa). Mesophase pitch with fine-flow texture can be prepared by introducing more methylene groups, naphthenic structures, and aliphatic hydrocarbons during synthesis. Carbon fibers prepared from mesophase pitch show a split structure, and the thermal conductivity is 730 W/(m·K). This work provides theoretical support for lower toxicity and causticity and for reaction-controlled technology for the synthesis of high-purity mesophase pitch.
PubMed: 38611228
DOI: 10.3390/polym16070970 -
ACS Omega Mar 2024Refined asphalt was prepared by solvent extraction sedimentation based on the response surface design, using washing oil and kerosene as solvents and the coal tar pitch...
Refined asphalt was prepared by solvent extraction sedimentation based on the response surface design, using washing oil and kerosene as solvents and the coal tar pitch as raw materials. The mathematical models of the refined asphalt yield, quinoline insoluble (QI) content, ash content, solvent-to-oil ratio, aromatic-to-aliphatic hydrocarbon ratio, extraction temperature, and sedimentation time were proposed, analyzing the influence of each factor and their interactions on the response values. Therefore, the optimal combination of preparation process parameters and better operation window was obtained by optimizing the experiment. Meanwhile, refined asphalt with high QI content and low QI content was selected as raw material, and the needle coke was prepared through the process of carbonization and calcination. The influence of QI content on the composition and the structure of green coke and needle coke was investigated by X-ray diffraction (XRD), Raman spectra, and polarizing microscopy characterizations. The results showed that the solvent-to-oil ratio is 1.2, aromatic-to-aliphatic hydrocarbon ratio is 1.1, sedimentation time is 2 h, and extraction temperature is 110 °C, resulting in the yield of refined asphalt being 76%, QI content being less than 0.1%, and ash content being less than 0.05%, which meets the requirement of the high-quality needle coke. Otherwise, refined asphalt with lower QI content easily generates a mesophase with more fibers and a large structure in the thermal conversion process, and the corresponding green coke and needle coke have a relatively regular carbon microcrystalline structure.
PubMed: 38524443
DOI: 10.1021/acsomega.3c10019 -
Microsystems & Nanoengineering 2024The implementation of an intelligent road network system requires many sensors for acquiring data from roads, bridges, and vehicles, thereby enabling comprehensive...
The implementation of an intelligent road network system requires many sensors for acquiring data from roads, bridges, and vehicles, thereby enabling comprehensive monitoring and regulation of road networks. Given this large number of required sensors, the sensors must be cost-effective, dependable, and environmentally friendly. Here, we show a laser upgrading strategy for coal tar, a low-value byproduct of coal distillation, to manufacture flexible strain-gauge sensors with maximum gauge factors of 15.20 and 254.17 for tension and compression respectively. Furthermore, we completely designed the supporting processes of sensor placement, data acquisition, processing, wireless communication, and information decoding to demonstrate the application of our sensors in traffic and bridge vibration monitoring. Our novel strategy of using lasers to upgrade coal tar for use as a sensor not only achieves the goal of turning waste into a resource but also provides an approach to satisfy large-scale application requirements for enabling intelligent road networks.
PubMed: 38476478
DOI: 10.1038/s41378-024-00670-z -
ACS Omega Feb 2024This paper explores the preparation of mesophase pitch by employing supercritical fluid extraction on coal tar pitch sourced from a coal chemical company. The raw...
This paper explores the preparation of mesophase pitch by employing supercritical fluid extraction on coal tar pitch sourced from a coal chemical company. The raw material undergoes pretreatment using various extraction solvents, and the resulting refined components are thermally polycondensed in a laboratory microreactor to create mesophase pitch. Qualitative and quantitative analyses of the mesophase pitch's structure are conducted through polarized light microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and other analytical methods to identify an optimal supercritical fluid extraction pretreatment solvent for coal tar pitch. The results reveal that using -hexane solvent in the supercritical fluid extraction process yields a mesophase pitch with a remarkable mesophase content of 90.07%, displaying excellent optical texture distribution, superior directional arrangement and order, the closest lamellar accumulation, and the highest degree of anisotropy and graphitization.
PubMed: 38371791
DOI: 10.1021/acsomega.3c08206 -
ACS Omega Jan 2024Pyrolysis is a technology capable of harnessing energy from challenging-to-recycle plastics, thus mitigating the necessity for incineration or landfill disposal. To...
Pyrolysis is a technology capable of harnessing energy from challenging-to-recycle plastics, thus mitigating the necessity for incineration or landfill disposal. To optimize the plastic pyrolysis process, reliable models for product yield prediction are imperative. This study endeavors to determine the suitability of lumped models, a widely used approach for modeling biomass and coal pyrolysis, in accurately estimating product yields in the context of plastic pyrolysis. To address this question, three lumped models with parallel and competitive reaction mechanisms were compared and fitted to experimental data collected across a broad temperature range. The aim is to identify which models can elucidate the most appropriate reaction pathway for the plastic pyrolysis process. The first model in this study assesses whether the commonly employed wood pyrolysis kinetic models can effectively fit the experimental data from plastic pyrolysis. Subsequently, the final two models introduce additional reactions into the pyrolysis process, prompting the authors to investigate the necessity of these supplementary reaction pathways for accurately predicting plastic pyrolysis outcomes. This investigation seeks to pinpoint the essential terms and discern which ones may be safely omitted from the models. The results of the study reveal that the model incorporating secondary tar reactions with gas, tar, and char is the most precise in predicting the products of plastic pyrolysis, surpassing all other combinations evaluated in this research.
PubMed: 38313546
DOI: 10.1021/acsomega.3c08306 -
ACS Omega Jan 2024This work investigates the structural characteristics and graphitizability of tars obtained from thermal pyrolysis versus the reactive microwave (MW) plasma pyrolysis of...
This work investigates the structural characteristics and graphitizability of tars obtained from thermal pyrolysis versus the reactive microwave (MW) plasma pyrolysis of coals. Powder River Basin (PRB) coal tars obtained by thermal pyrolysis have been compared with tars obtained from MW plasma pyrolysis containing H. To study the effect of coal rank and MW plasma environment, the PRB tars have been compared with Middle Kittanning (MK) coal tars obtained from an argon-hydrogen MW plasma (hp) and an argon-CO MW plasma (cdp) environment. Fourier transform infrared spectroscopy has been used for investigating the structural differences among the tar samples. The tars have been graphitized (GR-) at 2500 °C and the graphitic quality assessment has been performed using X-ray diffraction and transmission electron microscopy. MW plasma-derived tars have higher aromaticity, lower condensation, and lower oxygenated molecules compared to thermally derived tars. These advantageous features of MW plasma-derived tars lead to the formation of crystallites several times larger than thermally derived tars after graphitization. When considering coal of the same rank (bituminous), the choice of the MW plasma environment has a substantial impact on the graphitic quality of the tars. The utilization of MW plasma containing H leads to a significant increase in both the crystallite diameter (by 60%) and stacking height (by 40%) compared to MW plasma containing CO. Furthermore, within the same MW plasma environment, the coal rank plays a significant role in determining the crystallite diameter and stacking height of the GR-tars. In particular, GR-MK tar obtained from hp exhibits a 135% larger crystallite diameter and 85% larger stacking height compared with GR-PRB tar obtained from hp. These findings demonstrate the potential to tailor the composition of coal-derived tars and consequently influence their graphitizability by adjusting the reactive environment during MW plasma treatment.
PubMed: 38284088
DOI: 10.1021/acsomega.3c06666