Frontiers of Environmental Science & Engineering
·
2025
·Vol. 19
·期 3
·1-15
·
IF 6.4
Zhang Xiang,Tian Jian,Hu Tanghui,Yue Guangyong,Liu Xianlong,Zhou Wen,Liu Xiaohong,Wang Xinye
Combining pulverized coal gasifiers with cement kiln production is promising for application in low-cost and efficient NO reduction. This paper presents a pulverized coal gasifier catalytic denitration technique and investigates the homogeneous reduction (by CO and CH 4 ) and heterogeneous catalytic reduction (by coke, CaO, MgO, and Fe 2 O 3 ) of NO. A combination of Chemkin simulations and fixed-bed experiments is used to elucidate the reaction pathways and key intermediates of NO reduction by carbon-based gases. In addition, the activation energies for different catalyst combinations were analyzed via reaction kinetics. The results demonstrate that the presence of small amounts of O 2 inhibits NO reduction by CO but promotes NO reduction by CH 4 . The NCO• radical is essential for the NO reduction process, and the generation of this radical depends on the CH 4 cleavage intermediate and O• radical. CaO and Fe 2 O 3 exhibit more significant catalytic effects on NO reduction by carbon-based gases than the other catalysts tested. The presence of a small amount of O 2 in the reacting gas mixtures facilitates the NO reduction reaction. The activation energy is reduced to 1.02 kJ/mol, and the NO conversion reaches 99.80% when the catalyst is C + CaO + MgO + Fe 2 O 3 and the gas composition is CO + CH 4 + O 2 . This work provides theoretical support and data recommendations for the use of pulverized coal gasifiers for the denitrification of cement kilns.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Xiaolong Gong,Wenming Jiang,Shengli Hu,Zhiyuan Yang,Xinwang Liu,Zitian Fan
Clay sand casting generates a large amount of foundry dust (FD), and the presence of coal powder in the FD makes it difficult to recycle and utilize. The landfill of the FD creates a serious environmental pollution and wastes a valuable resource. To improve the above situation, the FD was analyzed and characterized by X-ray fluorescence spectrometer (XRF), X-ray diffraction (XRD) and electron probe microanalyzer (EPMA). An ultrasonic-assisted flotation process was developed for the comprehensive utilization of the FD, and the effects of ultrasonic time on the flotation performance and flotation kinetics were investigated. In addition, the two-stage flotation of the FD was conducted. Obtained results showed that the FD mainly consisted of coal powder and clay minerals, and the coal powder was covered by clay minerals. The separation efficiency of the coal powder and clay minerals can be significantly enhanced by ultrasonic pretreatment , and the optimal ultrasonic time was 30 min. The flotation kinetics analysis results indicated that the first-order model with rectangular distribution was more reasonable for the data fitting of the ultrasonic-assisted flotation. Furthermore, the concentrate and tailings obtained by the two-stage flotation had achieved an acceptable result, favoring the comprehensive utilization of the FD.
研究领域:
环境科学
·
材料科学
·
矿物加工工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Can Chen,Zheng Zhang,Pengyu Chen,Jiguang Huang,Heng Zhang,Dan Gao,Tao Li,Haiping Chen
Solar-interfacial evaporation has shown great potential for desalination using green energy. However, salt accumulation and long-term stability of the evaporators are urgent problems. Here, we designed a ceramic interfacial evaporator using black glaze and coal fly ash (CFA) with durability and technological maturity characteristics. A porous CFA ceramic substrate was prepared by the dry pressing method, and the black glaze was coated on the surface as a photothermal material. The thermal conductivity and porosity of the CFA ceramic are 0.564 W·m −1 K −1 and 40 %, respectively. The average evaporation rate was 1.443 kg·m −2 h −1 under one sun. Outdoor solar desalination experiments were conducted. The highest evaporation rate was 2.949 kg·m −2 h −1 under natural sunlight. The ceramic evaporator showed good salt resistance during two days of continuous desalination experiments. This work highlights the feasibility of using CFA-based ceramic evaporators for efficient solar-driven seawater desalination.
研究领域:
材料科学
·
环境科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Wei Liu,Jianwei Liang,Chong Fu,Baobao Zeng,Meipeng Huang,Gao Yang,Xudong Luo,Di An,Sai Wei,Zhipeng Xie,Guangzhou Xu
The coal fly ash (CFA) produced from coal-fired power generation is classified as a common solid waste; thus, improving the recovery and utilization rate of CFA is highly desirable. In this study, a novel strategy using CFA and Al 2 O 3 as raw materials, to prepare hierarchically porous ceramic composites that serve as potential candidates for future building materials is developed. In this process, the well-developed self-assembly method in which an anionic modifier is used to prepare hydrophobic powders that form an attractive oil/water network via electrostatic interactions , thereby yielding honeycomb-like structures. In order to explore the mechanism of preparation, five samples with different mixture ratios of alumina and CFA were prepared according to 1: 0, 2: 1, 1: 1, 1: 2, and 0: 1 (Alumina: CFA). Compared with the sample prepared with pure CFA, the as-prepared CFA/Al 2 O 3 composite exhibited both superior porosity and high mechanical property. When the porosity is as high as 73 ± 0.17%, the compressive strength is as high as 80.9 ± 3.4mpa (alumina: CFA = 1:1). As the porosity decreases to 49.3 ± 0.7%, the compressive strength reaches 159.33 ± 36.89mpa (alumina: CFA = 1:2). Moreover, this work obtains the highest compressive strength-porosity related B-value in comparison to previously reported CFA-based composites and provides a new insight into the effective recycling of CFA and offers a novel approach to prepare CFA/Al 2 O 3 composite with excellent overall mechanical properties .
研究领域:
材料科学
·
环境科学
·
工程学
✓ 已验证
产品关联
DOI
高影响因子
WASTE MANAGEMENT
·
2025
·
IF 7.1
Ke Li,Jie Deng,Ying Zhu,Weiyi Zhang,Tao Zhang,Chao Tian,Jinwei Ma,Yingying Shao,Yanfeng Yang,Yanqiu Shao
Municipal solid waste incineration fly ash (MSWIFA) is considered a hazardous solid waste, traditionally disposed by solidified landfill methods. However, solidified landfills present challenges with leaching heavy metals, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). To address this issue, this study examined two pretreatment methods for MSWIFA: sintering at 850℃ for 30 min and washing with three water baths (20 min each) at a 3:1 liquid–solid ratio. Then, the pretreated MSWIFA was employed in geopolymer synthesis, along with gold tailings (GT) and coal fly ash (CFA). The optimal raw material ratio was GT:CFA:MSWIFA = 5:4:1 after pretreatment, which resulted in maximum compressive strengths of 20.95 and 25.87 MPa for the sintered and washed samples, respectively. Washing removed 87.3 % of soluble chlorides from MSWIFA, enhancing the compressive strength of the geopolymer. High-temperature treatment effectively reduced the leaching concentrations of heavy metals and the toxic equivalent quantity (TEQ) of PCDD/Fs. The leaching concentrations of heavy metals (Cu, Zn, Cd, Pb) and the TEQ of PCDD/Fs were all below the limits established by Chinese standards GB 5085.3–2007 and HJ 1134–2020. X-ray Diffraction, Fourier transform infrared spectrometry, scanning electron microscopy, and energy dispersive spectroscopy analyses revealed that the primary hydration products of the geopolymer are C–(A)–S–H gels. Washing treatment facilitated the formation of ettringite and Ca(OH) 2 , which enhanced the pore structure and optimized the performance of the geopolymer. Thermogravimetric analysis revealed the good thermal stability of the geopolymer, indicating that the high-temperature and washing pretreatments minimally impacted its thermal stability.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FUEL
·
2022
·
IF 8.035
Minggao Yu,Fengchuan Wang,Tao He,Haitao Li,Shixin Han,Rongyang Lou,Kai Zheng,Yingying Yu
In this work, with the assistance of the intercalation modification approach, three kinds of intercalated compounds, dimethyl sulfoxide (DMSO), potassium acetate (KAc), and ammonium sulfamate (AS) were successively employed for modification on kaoline to prepare a modified kaolin inhibitor. Then, the TG/DTG test, SEM observation, XRD characterization, and FTIR analysis were respectively utilized to probe the thermal stability, surface structures, and functional groups of the modified kaoline inhibitor. Moreover, the compound inhibitors fabricated by modified kaoline powder blending with ammonium polyphosphate (APP) of different mass fractions were employed to inhibit the explosions of methane/pulverized coal blenders. In the explosion inhibition experiments, the concentrations of methane and coal dust were respectively selected for 9.5 % and 0.105 g/L, while the compound inhibitors with seven various mass fractions of 0.05, 0.075, 0.1, 0.125, 0.15, 0.175, and 0.20 g/L were severally chosen to explore its inhibiting effect on methane/pulverized coal blenders using the 20-L standard spherical explosion apparatus. Results show that both the modified kaoline inhibitor and its compound inhibitor demonstrate a prominent inhibiting effect on methane/pulverized coal blenders. Besides, the inhibiting effect presents the most outstanding as the mass fraction for APP of the compound inhibitor occupies 35 %. Under such a circumstance, the P max of the hybrid mixture decreases from 0.784 to 0.47 MPa and declines by 40.05 % after adding the compound inhibitor, the dP / dt max declines to 3.03 MPa·s −1 while the t P max delays to 1.122 s. Finally, we theoretically analyzed the suppression mechanism of the modified kaoline-containing compound inhibitors on the explosions of methane/pulverized coal blenders based upon the physicochemical properties of the raw samples and the solid particles collected from the post-explosion experiments from the macro and molecular-kinetics perspectives. This preliminary study would contribute to the development of high-efficiency inhibitors for preventing methane/pulverized coal-involved explosion disasters.
研究领域:
矿业安全工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）