ACS Omega
·
2024
·
IF 3.7
Hong Zhang,Zongquan Zhao,Zihan Wang,Shibin Nie,Chao Han
Inhibitory foam technology plays an important role in inhibiting coal spontaneous combustion. To enhance the stability and inhibitory performance of inhibitory foam for coal spontaneous combustion, a novel physicochemical composite inhibitor was developed in this work. CaCl2 was chosen as an inorganic salt physical inhibitor to compound with the chemical inhibitor melatonin (MLT) due to its corresponding good foam stability. When the mass ratio of CaCl2 to MLT was 4:1, the lowest CO release concentration of 7337.06 ppm at 200 °C was observed in the composite inhibitor-treated coal. Furthermore, the addition of 20 wt % of the composite inhibitor resulted in a foam half-life of 3067 min, which was 5.89 times longer than that of the water-based foam. In comparison with the water-based foam, the inhibitory foam based on 20 wt % CaCl2–MLT composite inhibitor exhibited more excellent foam stability, wetting ability, and inhibition performance. The release of CO at 200 °C was 7854.6 ppm, showing a reduction of 63.2% compared to the raw coal. Moreover, the composite inhibitory foam could significantly delay the onset of the characteristic temperature and reduce the weight change during the decomposition stage by 12.8%.
研究领域:
矿业工程
·
消防工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Fei Gao,Zhe Jia,Ya-fei Shan,Yifei Teng,Ying-di Li,Xin-ge Pu
The low-temperature oxidation spontaneous combustion of coal was caused by the active groups in its structure. The oxidation mechanism of carbon and oxygen functional groups in coal had been extensively studied, but there were few reports on the study of sulfur functional groups initiating the coal spontaneous combustion. To investigate the influence of organic sulfur functional groups on the spontaneous combustion of high-sulfur coal and explore its transformation characteristics, the low-temperature oxidation experimental system was used to study the spontaneous combustion tendency of coal with similar metamorphic degrees and different organic sulfur contents. The variations of element forms and organic sulfur functional groups were analyzed by X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy during low-temperature oxidation of coal and model compounds. The results showed that the forms of organic sulfur in coal mainly included mercaptans, thioethers, thiophenes, sulfones (sulfoxides), and sulfates, and the low-temperature oxidation of coal was not only related to the content of organic sulfur but also related to its type. The coal samples, which possess a low content of total sulfur and a small proportion of active organic sulfur groups such as mercaptans and thioethers, had a lower concentration of indicator gas and a smaller tendency to coal spontaneous combustion. After low-temperature oxidation, the content of mercaptan, thioether, thiophene, methyl(methylene), and pyridine in coal decreased, and the content of oxygen-containing groups such as sulfone (sulfoxide), sulfate, carboxyl, and nitrogen oxide increased. The elements of S, C, and N all changed to a high-valent state. In the oxidation reaction of model compounds, mercaptans were more reactive than thiophenes in the low-temperature region, and the oxidation of thiophene could direct form sulfone (sulfoxide), while the oxidation of mercaptan formed disulfide first. It is speculated that low-valence sulfur migrated to a high-valent state by providing sulfhydryl radicals (•SH) and sulfur radicals (C–S•) combined with active oxygen atoms. After the low-temperature oxidation reaction of model compounds, some organic sulfur existed in the form of aromatic sulfur or sulfur oxides and a small part of sulfur escaped as SO2 and H2S gases in the solid oxidation product.
研究领域:
矿业工程
·
化学工程
✓ 已验证
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Chunhua Zhang,Jiahui Shen,Ji Li,Mei Wan
To study the inhibition characteristics of different chloride salts on the spontaneous combustion of coal and to further reveal why magnesium chloride shows a different inhibitory effect, coal samples from FuSheng Coal Mine No. 15 in Shanxi Province were selected. Based on the characteristics of functional group absorption peak at different temperature, the composition changes and reactivity ranking of the functional groups in oxidized coal samples were tested by thermal oxidation experiments and infrared spectroscopy and analyzed to obtain the chain thermal reactions of different active groups. The weight-loss process and heat release characteristics of raw coal and three chloride salt-containing coal samples (sodium chloride, potassium chloride, and magnesium chloride) were compared and analyzed by synchronous thermal analysis experiments, and their inhibition reaction mechanism were studied. The results showed that different functional groups reacted at different low-temperature stages, and the active groups containing C–H, O–H, C-O, and C = O bonds were important during the spontaneous combustion of coal. In the chain thermal reactions with different active groups, heat and oxidative cleavage of the C-O and O–H bonds determined the chain development of different functional groups, and the R·, RO·, H·, and ·OH, chain thermal reaction products again acted as reactants that promoted further development of the reaction. Sodium chloride and potassium chloride played inhibitory roles in the dehydration-desorption stage and dynamic equilibrium stage through water evaporation and heat absorption, while magnesium chloride participated in the whole coal-oxygen reaction process. The inhibitory mechanism included dehydration and heat absorption by MgCl 2 ·6H 2 O, the complex dehydration of active groups containing O–H, the precipitation and oxygen insulation of [(SH·) n ]Mg and Mg(OH) 2 , the nucleophilic substitution of α-H for RCH 3 and RCH 2 OH groups, and the formation of H…Cl…H bonds.
研究领域:
化学工程
·
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Fei Gao,Zhe Jia,Qihui Bai,Jianjun Dong
Inhibitors play an important role in preventing and controlling coal spontaneous combustion (CSC). In this study, the inhibitory effects of antioxidant-reduced glutathione (G-SH) on CSC were examined. Thermogravimetric-differential scanning calorimetry (TG-DSC), cross-point temperature (CPT), and oxidation product tests were used to examine the effect of G-SH on the tendency of CSC and compare the discrepancy in the inhibition effect of G-SH and the halogen inhibitor. The changes in the free radical type, concentration, and surface functional groups in coal before and after the addition of G-SH were analyzed using electron spin resonance spectroscopy (ESR) and Fourier transform infrared spectroscopy (FT-IR). Six common active radical models were constructed, and the thermodynamic parameters of the reaction were calculated using density functional theory (DFT). The results revealed that G-SH inhibits the spontaneous combustion of coal. The inhibitory effect of G-SH was significantly stronger than that of the halogen salt inhibitors CaCl 2 and MgCl 2 , and the higher the concentration of G-SH, the stronger is the inhibitory effect. The characteristic temperature points in the thermogravimetric experiment of coal samples with G-SH shifted to a higher temperature zone, and the CO concentration and oxygen consumption were lower than those of raw coal. After G-SH treatment, the type and relative concentration of free radicals in coal were lower than those in raw coal, the content of aliphatic hydrocarbon functional groups and oxygen-containing functional groups decreased, and the content of sulfur-containing functional groups increased. According to the calculation of Gibbs free energy and reaction enthalpy, G-SH can effectively neutralize the active free radicals in the process of coal oxidation, and the reaction activity with the free radicals in the process of coal oxidation is ·OOH > ·OH > ·CH 3 > RO· > R· > ROO·. According to the experimental results, it is inferred that G-SH continuously supplies a large number of hydrogen donors (·H) for the reaction during the oxidation process and simultaneously neutralizes carbon free radicals and carbon oxygen free radicals, thereby reducing the concentration and reactivity of free radicals in the whole chain reaction process and blocking the occurrence of coal-oxygen composite reaction.
研究领域:
能源科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
E-POLYMERS
·
2015
·Vol. 15
·期 5
·361-368
·
IF 0.569
Xiangming Hu,Weimin Cheng,Zhenlu Shao
Authigenic gas foaming hydrogels were synthesized using chitosan (CS), acrylic acid, and attapulgite (APT) as hydrophilic monomers; potassium persulfate as initiator; N,N′-methylenebisacrylamide as cross-linker; and sodium carbonate (Na 2 CO 3 )/acetic acid as foaming agent. Effects of different monomers, amount of foaming agent, and temperature on swelling ratio (SR) of the hydrogels were examined. Morphology, structure, and thermal stability of authigenic gas foaming hydrogels were studied using field emission scanning electron microscope, Fourier-transform infrared spectroscopy, and synchronous thermal analysis. Scanning electron microscope images reveal apparent pores on hydrogels, produced by foaming agent Na 2 CO 3 /acetic acid. Therefore, more foaming agent would bring more pores on hydrogels. Synchronous thermal analysis results suggest that higher amount of CS would result in higher thermostability of hydrogels. However, APT has no substantial effect on thermal stability. SR decreases with increasing amount of CS. Hydrogels prepared at 70°C reaction temperature exhibit maximum swelling. Furthermore, SR decreases with higher covalence of saltion.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION SCIENCE AND TECHNOLOGY
·
2024
·
IF 1.7
Lianquan Suo,Zhilin Xi,Tong Xia,Tao Chen,Jiawei Han
A new type of biomass environmentally friendly hydrosol (DEP) was proposed to inhibit coal spontaneous combustion (CSC). The DEP consists of two parts, the PDopa side chain solution formed by the redox reaction of Dopa and EGCG and the main chain sol solution formed by the free radical polymerization of AA under the action of APS initiator. The −COOH, −NH2, and −OH in Dopa can be grafted onto the skeleton of the main chain via double strong hydrogen bonding interactions with the −COOH group in PAA to form a stable three-dimensional cross-linked network structure. DEP can inhibit CSC through three aspects: oxygen isolation, increasing the activation energy of coal oxidation, scavenging active groups and free radicals. The calculation simulation results show that EGCG in DEP can remove various active free radicals with lower activation energy at room temperature, breaking the chain cycle reaction of coal spontaneous combustion, which proves its high efficiency. This study provides a new way to apply mussel-inspired adhesion mechanisms to the prevention of CSC.
研究领域:
能源科学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION SCIENCE AND TECHNOLOGY
·
2022
·
IF 2.133
Chao Han,Shibin Nie,Zegong Liu,Jinian Yang,Hong Zhang,Jiayi Li,Haoran Zhang
The preparation of gel foams with high stability for inhibiting coal spontaneous combustion remains a huge challenge. In this paper, a highly stable gel foam (SCTH) was developed by introducing nano-hydroxyapatite (HAP) into gel foam system (sodium alginate/calcium L-lactate/tannic acid/composite forming agent). The effects of HAP on the foam performances of SCTH were analyzed. The results showed that HAP could improve the stability of SCTH by forming hydrogen bonds, metal ion bonds with the system and interfacial barriers. After 100 days, SCTH without HAP had only 44.8% of the foam volume remaining. The SCTH with 1.2 wt% HAP had 80% of the volume remaining. In addition, the SCTH had better safety. Thermogravimetric analysis showed that the SCTH could improve the maximum weight loss rate temperature, and increase the residual weight of the coal after thermal decomposition. The coal temperature-programmed oxidation experiment showed that the SCTH could increase the temperature of coal entering the rapid oxidation stage from 120 to 190°C, and the CO inhibition rate was 85.3% at 200°C. Fire suppression experiment showed that the SCTH could reduce the temperature of burning coal by 81.9% within 10 min, thus achieving rapid fire suppression. X-ray photoelectron spectroscopy analysis showed that the SCTH could more effectively reduce the total content of C=O and -COO in coal and block the chain cycle reaction of coal. This work presents a new design idea for using multifunctional nanoparticles to prepare highly stable gel foams with excellent inhibition performance of coal spontaneous combustion.
研究领域:
材料科学
·
能源工程
·
燃烧学
✓ 已验证
产品关联
DOI
高影响因子
COMBUSTION SCIENCE AND TECHNOLOGY
·
2023
·
IF 1.9
Guolan Dou,Chen Wang,Chenghui Yan,Liying Zhang,Lingling Gao,Gen Liu,Tian Zhang,Jingqi Wang,Jingyu Wang
Dry water is a green fire extinguisher agent with good cooling and fluidity that is composed of hydrophobic silica and tiny liquid droplets. However, the structure of dry water is unstable and easily broken during production, transportation and storage. In this study, a lignin-based hydrogel was employed as the core material and hydrophobic silica as the wall material to develop a hydrogel reinforced dry water suitable for preventing coal spontaneous combustion. The bulk density, fluidity, stability and particle size distribution of the synthesized hydrogel reinforced dry water were all measured. Compared to traditional dry water, the lignin-based hydrogel reinforced dry water had a better angle of repose and outflow velocity, measuring 19.53° and 9.40 mL/s, respectively. Additionally, the bulk density and water retention in an open environment were 2.6% and 5.2% higher than traditional dry water, respectively. The particle size distribution of the lignin-based hydrogel reinforced dry water is likewise more uniform. Thermal analysis was used to examine the effect of the reinforced dry water on coal oxidation. The results showed that the reinforced dry water reduced the mass increase caused on by oxygen adsorption, hence inhibiting coal oxygen chemisorption. Further investigation revealed that addition of reinforced dry water improved the inhibitory performance of coal spontaneous combustion by decreasing coal oxidation heat release by 4.2% and 11.2%, respectively, in comparison to raw PING and YZ coal, and by increasing coal oxidation activation energy, with maximum increases of 23 and 265 kJ/mol for PING and YZ, respectively.
研究领域:
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2018
·
IF 3.441
Zhilin Xi,Xiaodong Wang,Xiaoli Wang,Li Wang,Ding Li,Xiangyu Guo,Liwei Jin
Polymorphic foam clay (PFC) was proposed to retard the spontaneous combustion of coal. It is mainly synthesized using foaming clay and auxiliary solutions. When the ratio of foaming clay solution to auxiliary solution was ˜1.0 wt. %, the generated PFCs had the best performance. The sol-gel foams that could be obtained as gas were injected into the synthetic solution, which had an excellent wettability on the coal surface due to the synergistic action of polyethylene oxide and sodium dodecyl sulfate. PFCs were obtained with the reaction of organic acids and sodium silicate, and their times of liquidity and self-hardening loss were 180 and 225 s, respectively. The mechanisms of PFC inhibiting the spontaneous combustion of coal were analyzed by a simultaneous differential scanning calorimeter/thermogravimetric analyzer, an XP-550C polarizing microscope linked to a CK 300 thermal station, scanning electron microscopy, a simultaneous differential thermogravimetric scanning calorimetric analyzer linked to a mass spectrometer and X-ray photoelectron spectroscopy. Before 239 °C, the PFC was always in an endothermic state, so it could adsorb significant heat produced by the low-temperature oxidation of coal to cool the coal body. The fused PFC also could form a thin whole colloid clay layer to cover the coal surface and effectively seal gaps and cracks in the coal from oxygen ingress, thereby preventing coal from contacting oxygen. The colloid clay could retain water to increase the moisture of the coal body, resulting in the prevention of the generation of new alkyl groups from cycloalkanes and bridge bond breakage, thereby decreasing the concentration of active groups in the coal. The colloid clay possessed organic acidity that could consume active free radicals.
研究领域:
矿业工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Yuanyuan Li,Xiaoling Xu,Ran Zhang,Xingbao Yang,Kun Jia
Traditional coal mine fire suppression methods face critical limitations, including short-term efficacy, poor penetration in concealed coal seams, and environmental risks from chemical residues. To address these challenges, this study developed a biomaterial-based composite inhibitor integrating physical isolation, free radical quenching, and antioxidant slow release for sustainable prevention of spontaneous coal combustion. A novel antioxidant-loaded composite was synthesized using hollow mesoporous TiO 2 nanoparticles (HM-TiO 2 ) as carriers, which were functionalized via layer-by-layer self-assembly (LBL) of chitosan (CS) and phytic acid (PA) to encapsulate tea polyphenol (TP). This design enables the TP antioxidant activity and low release while leveraging CS/PA’s catalytic char-forming capacity. The chemical composition and micromorphology of the composite were systematically characterized through FTIR, XRD, SEM, and TEM analyses. Programmed temperature oxidation experiments combined with thermogravimetric (TG) and thermogravimetric-Fourier Transform Infrared Spectroscopy (TG-FTIR) measurements were conducted to evaluate inhibition performance by tracking mass loss, characteristic gas emissions, and radical intermediates. Key findings demonstrate that the composite inhibitor: Prolongs coal ignition delay by 48 % compared to untreated coal, attributed to the synergistic barrier effect of the TiO 2 @CS-PA framework and TP’s radical scavenging activity; Reduces CO, CO 2 , CH 4 and H 2 O emissions during low-temperature oxidation; Maintains structural stability above 400 °C, with TiO 2 catalyzing dense char layers to isolate oxygen diffusion. This multifunctional composite overcomes the trade-off between inhibition longevity and environmental compatibility observed in conventional inhibitors (e.g., MgCl 2 , KMnO 4 ), offering a scalable solution for fire prevention in high-level mining areas. The bio-based components (CS, PA, TP) further ensure ecological safety, aligning with green mining initiatives.
✓ 已验证
产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Guojun Zhi,Rong Xie,Ruigang Yang,Junqi Cui,Xinyu An,Yulong Zhang
This paper proposes a new montmorillonite-type multiple network composite gel for the prevention of coal spontaneous combustion. The first network is formed by the cross-linking of polyvinyl alcohol (PVA) and boric acid under alkaline conditions. The second network is formed as a result of intermolecular hydrogen-bonding interactions between polyacrylamide (PAM) and polyvinyl alcohol. Montmorillonite (MMT) is designed as the backbone material in the preparation of composite gels. The optimal ratios of the reactants of the composite gel were determined through orthogonal experiments. The experimental results showed that PVA had the greatest influence on the gelation time, whereas the PAM concentration had the strongest influence on the gel permeability. The optimal blending ratio was 4% MMT + 2.5% PVA + 1.5% PAM. The chemical performances of the composite colloids, such as inhibition rate, reactive functional groups, and kinetics, were investigated. Results showed that multiple network composite gels could effectively inhibit the coal spontaneous combustion reaction. Based on the principle of coal spontaneous combustion and the cross-linking network structure of the composite gel, the flame-retardant and fire-extinguishing mechanisms were also explored in terms of both physical and chemical inhibition pathways.
研究领域:
材料科学
·
能源科学
·
火灾防治
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Jian Qiao,Xiang-Ming Hu,Yun-Tao Liang,Qian Zhang,Wei Wang,Yan-Yun Zhao,Shuang Ju,Fu-Chao Tian
In order to improve the stability time and foaming ratio of gel foam, and change the traditional preparation method of gel foam. In this paper, using super-hydrophobic nanoparticles , PVA, sodium tetraborate and sodium bicarbonate as the main raw materials, based on the self-assembly effect of super-hydrophobic nanoparticles and hydrophilic macromolecules, a high-foaming gel foam (PGF) without foaming agent was prepared. Through the test, the foaming volume of the 100 ml PGF can reach 329 ml without adding foaming agent, which is 1.4 times of the traditional gel foam (TGF) and 1.2 times of the viscous foam (VF). Even without foaming agent, the PGF has a half-life of more than 13 days and can retain water for more than 15 h at 100 °C. Response surface analysis showed that the foaming performance of the PGF was affected by nanoparticles, sodium tetraborate and sodium bicarbonate, among which the content of nanoparticles was the main factor. At the same time, sodium tetraborate and sodium bicarbonate also significantly affect the water retention performance of PGF. Fire prevention experiments show that the gel foam prepared by this method also has excellent fire prevention ability, which can effectively inhibit the consumption of hydroxyl group and the generation of methyl and methylene group in the process of coal oxidation. Moreover, it can still play an inhibiting ability at a high temperature of 400 °C, and can effectively prevent the recurrence of coal fire after extinguishing. The development of PGF provides a new method for the preparation of gel foam in the future. At the same time, the application of foaming agent is avoided, which reduces the pollution of surfactant to the environment.
研究领域:
材料科学
·
消防工程
·
能源安全
·
高分子化学
·
界面科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）