FUEL
·
2022
·
IF 8.035
Yujie Hou,Zongqing Bai,Hao Lu,Zhihao Feng,Tingting Zhang,Yuxing Jia,Zhenxing Guo,Lingxue Kong,Jin Bai,Wen Li
Low-cost kaolin was modified by calcination at different temperatures, followed by HCl leaching, and used as catalyst for in-situ upgrading of Hami coal pyrolysis volatiles in a fixed-bed reactor. The catalyst characteristics, pyrolysis product distributions and tar properties were investigated by multiple methods to understand the relationship between catalyst properties and tar quality. The results indicated that calcination of kaolin promoted the formation of amorphous metakaolin, then the HCl leaching removed most metakaolin framework Al, leading to the production of abundant micro-/mesopores and acid sites. As the rising calcination temperature, the specific surface area and pore volume of acid-modified kaolin (AMK) showed a trend of increasing and then decreasing, and the Brønsted acid sites (BAS) displayed an increasing trend. Compared to non-catalytic pyrolysis, the high specific surface area and certain acid sites of AMKs enhanced the light tar fraction from 37.81 wt% to 43.00–48.45 wt%, and the relative content of aromatics in tar increased from 9.76% to 16.65–22.11%, with monocyclic aromatics, naphthalenes and polycyclic aromatics increasing to 3.5–4.2, 1.2–1.8 and 2.1–3.3 times higher, respectively. AMKs also reduced the content of element O in tar by 17.92–31.54% by promoting the deoxygenation reaction. The tar upgrading performance was determined by the BAS amount and the pore structure of AMKs together. Among all AMKs, AMK800 (calcined at 800 °C and treated by HCl) exhibited the optimum performance for heavy tar conversion, aromatics generation and oxygen removal due to its highest specific surface area and the maximum BAS except AMK900. The acid-modified kaolin has the potential to be an inexpensive and efficient catalyst for future practical applications of upgrading coal pyrolysis tar.
研究领域:
化学工程
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能源科学
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产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2024
·
IF 9.9
Jiacong Chen,Ming Zhao,Saleem Nawaz Khan,Yang Liu,Sheng Zhao,Weiguo Dong,Qingbin Song,Chao Wang
In recent years, biomass oxy-fuel gasification has prompted increased interest for its ability to produce a gas with low tar content and to assist in carbon reduction. It is noteworthy that the type of atmosphere is a crucial factor influencing the devolatilization process in biomass gasification and the specific mechanisms by which an oxy-fuel atmosphere influences the devolatilization process remain inadequately explored. This work aimed to investigate the effect of various reaction atmospheres on devolatilization behavior, reaction kinetics, intermediate product formation, and biochar functional groups (BFGs) evolution. In comparison to an inert atmosphere, the oxy-fuel atmosphere facilitated the release of volatiles, and enhanced energy self-sustainability within the devolatilization system. The presence of O 2 and CO 2 promoted the generation of potential anhydrosugars while suppressing the formation of phenolic compounds. The synergistic effect present in the oxy-fuel atmosphere augments the exothermic effect and promotes the release of volatile and alkane gases during the devolatilization process. Furthermore, as oxygen concentrations increased in the reaction atmosphere, the sequential response of BFGs primarily followed the order: C-O → aromatic ring → C-OH/C–H/COO– → C=O. Moreover, advanced characterization analyses revealed that the oxy-fuel environment was more effective in promoting the aromatization and pore structure of biochar than an inert atmosphere. Collectively, these findings have substantial implications for reaction modeling in biomass fixed-bed gasification under real gas atmospheres and guide future research on tar control strategies.
研究领域:
能源科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Wangui Chen,Weitong Pan,Lili Zhao,Longfei Tang,Lu Ding,Xueli Chen,Fuchen Wang
Low specific surface area (SSA) in hard carbon anodes is crucial for enhancing the initial Coulombic efficiency (ICE) and reversible capacity of sodium-ion batteries (SIBs). Conventional strategies for SSA reduction within high-temperature carbonization processes often rely on additional energy-intensive thermal treatments or complex processes, presenting significant barriers to practical application. This study introduces a simplified and effective approach that operates within a standard high-temperature framework (1300 °C) by solely controlling the packing thickness of coconut shell char (CSC) precursors. Increased packing thickness induces diffusional resistance, hindering volatile release and achieving a volatile release reduction of 7.68 %. This confinement effect promotes in-situ secondary cleavage of volatiles, accelerating carbon deposition and reducing surface defects. Consequently, SSA decreases significantly by 71.52 %, while closed pore formation is enhanced. The optimized CSC-HPT-1300 exhibits dramatically improved electrochemical performance over the low-packing-thickness control, achieving a 15.48 % higher ICE (85 %), a 15.39 % increase in reversible capacity (280 mAh g −1 ), and a 25.90 % enhanced plateau capacity (209 mAh g −1 ). Furthermore, this strategy concurrently increases carbonization mass yield by 4.64 %. This thickness-controlled carbonization presents a straightforward and scalable optimization to standard high-temperature processing for fabricating low-surface-area hard carbons, advancing sustainable SIBs development.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL ATOMIC SPECTROMETRY
·
2024
·Vol. 39
·期 12
·2974-2981
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IF 3.1
Wan-Feng Zhang,Qing Yang,Xiao-Ping Xia,De-Wen Zheng,Ze-Xian Cui,Yan-Qiang Zhang,Yi-Gang Xu
Sample preparation is a critical step to achieve reliable in situ chemical analysis. Sample mounting technique with a tin-based alloy was developed in recent years, which is particularly useful for high-precision volatile analyses by secondary ion mass spectrometry (SIMS). However, the success of this technique is hindered by challenges, such as complex alloy preparation and potential Pb contamination. Herein, we introduce a new Sn–Bi alloy preparation method that may overcome these hurdles and assess its potential as a standard preparation method for in situ volatile and isotope analyses. This new alloy can be manufactured with commercially available pure tin and bismuth metal (atomic Sn : Bi = 42 : 58), and its production requires only a heating plate and clean containers. This ensures its high accessibility to laboratories worldwide. The Pb content of the alloy is dependent on the tin and bismuth used. The material (Sn and Bi) from three different manufacturers were evaluated in this study, resulting in the virtually Pb-free MAC alloy (Pb <0.2 μg g−1). The SIMS U–Pb dating results of the zircon standards (Qinghu, Plešovice, and SA01) are consistent with the recommended values (within error). Furthermore, the mounted samples exhibit satisfactory relief on this alloy, suggesting that this alloy material is appropriate for the analysis of oxygen isotopes. The routine external precision of oxygen isotope ratios is better than 0.30‰ (2sd), on par with that obtained with epoxy mounts. The water background in the SIMS sample chamber can be recovered rapidly after sample transfer from the storage to the sample chamber. Hence, this tin-based alloy is suitable for sample mounting for SIMS volatile and isotope (incl. U–Pb) analyses.
研究领域:
材料科学
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分析化学
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地球化学
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DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2023
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IF 9.8
Teng Xie,Lixin Zhao,Zonglu Yao,Kang Kang,Jixiu Jia,Tingxia Hu,Xinyi Zhang,Yuxuan Sun,Lili Huo
Investigation on the distribution and mechanism of co-pyrolysis products is vital to the directional control and high-value utilization of agriculture solid wastes. Co-pyrolysis, devolatilization, kinetics characteristics, and evolution paths of corn stalk (CS) and low-density-polyethylene (LDPE) were investigated via thermogravimetric experiments. The co-pyrolysis behaviors could be separated into two stages: firstly, the degradation of CS (150– 400 °C); secondly, the degradation of CS (400– 550 °C). The devolatilization index (DI) increased with the addition of LDPE. Furthermore, a combination of devolatilization chemical analysis with product analysis to analyze the intrinsic mechanism during co-pyrolysis. The results indicated that the yield of alkanes and olefin in gas products increased with the addition of LDPE. Additionally, LDPE pyrolysis maybe abstract hydrogen from CS pyrolysis and evolved into hydrogen, methane, and ethylene. Further, the co-pyrolysis kinetic parameters were computed by using model-free isoconversion methods, which showed promotion of CS pyrolysis and the reduced activation energy. All the activation energy were declined, which indicated a “bidirectional positive effect” during co-pyrolysis. The mean activation energy of P-cellulose (P-CE), P-hemicellulose (P-HM), P-lignin (P-LG), and LDPE decreased by 23.49 %, 12.89 %, 15.36 %, and 27.82 %, respectively. This study further proves the hydrogen donor transfer pathway in the co-pyrolysis process of CS and LDPE, providing theoretical support for the resource utilization of agricultural solid waste.
研究领域:
化学工程
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环境科学
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能源工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Lulu Wang,Chenyang Zhou,Laihong Shen,Yuyang Long,Dongsheng Shen
Sulfur impurity in solid fuel should be paid attention to in the thermal process from the perspective of environment and sulfur recovery, especially the auto-thermal oxygen carrier aided pyrolysis/gasification (OCAP). To uncouple the complex sulfur transformation during OCAP of solid fuel and elucidate the main mechanism, several typical model compounds of various functional groups were used to investigate the kinetic analysis and sulfur transformation through temperature-programmed method. The OCAP process consisted of devolatilization and partial gasification. The activation energy of sulfur models devolatilization was less than that of partial gasification, because the required energy was much more to release lattice oxygen from oxygen carrier. Furthermore, the actual oxygen transport capacity of oxygen carrier (OC) redistributed the sulfurous gases. It was found that H 2 S was released earlier than SO 2 . H 2 S release was ascribed to the devolatilization including the reactions between radicals and hydrogen abstracted from base at low temperature (200–300 °C). The different contact modes between sulfur compounds and OC proved that S could be absorbed in the form of iron sulfide and incorporated into char at low temperature but released in the form of SO 2 by OC oxidation at the elevated temperature (400–600 °C), which was in accordance with the kinetic analysis. The migration of sulfur from disulfide had priority over that from monosulfide, and the sulfur connecting with dialkyl (benzyl) was easier to escape than that with diaryl (phenyl) in OCAP process. The fate of sulfur model compounds was conducive to reveal the complex behaviors of solid fuel with different sulfur species, and this work provides evidence to implement the desulfurization and sulfur recovery strategy.
研究领域:
化学工程
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环境科学
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能源技术
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2022
·
IF 4.326
Li-Yun Zhang,Jing-Pei Cao,Xue-Yu Ren,Xiao-Bo Feng,Jing-Xian Wang,Zi-Meng He,Tian-Long Liu,Zhen Yang,Xiao-Yan Zhao,Hong-Cun Bai
CeO2 receives extensive researches as an active component due to its providential catalytic center and favorable reducibility. Herein, a series of Ce-modified hierarchical ZSM-5 zeolites (FZ5) were prepared by HF (0.5 mol/L) etching followed by impregnation with different Ce loadings. The role of incorporating extra-framework Ce elements was assessed by catalytic upgrading of the cellulose pyrolysis volatiles to produce light aromatics (LAs). Introducing CeO2 could effectively regulate the acid properties of catalysts with an increase in Lewis acid sites and a decrease in Brönsted acid sites, which could significantly improve the catalytic performance. As a result, the selectivity toward LAs were significantly enhanced and the coke content dramatically decreased. The highest selectivity to LAs and the lowest coke content obtained over 1.0Ce-FZ5 zeolite (loading 1.0 wt % Ce) were 84.0% and 2.42 wt %, respectively. Additionally, the 1.0Ce-FZ5 catalyst exhibited excellent stability, maintaining nearly 90% carbon yield of LAs after the seventh regeneration test. CeO2 modification opened a simple and feasible way for promoting the LAs selectivity and catalyst stability during the reforming of biomass volatiles.
研究领域:
催化化学
·
生物质能源
·
材料化学
·
环境科学
·
能源化工
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2025
·
IF 6.2
Haoxin Jiang,Yuyan Zheng,Zhuoya Dong,Hui Ming,Xuqiang Guo,Lihua Cheng,Libo Zhang
The co-pyrolysis of petroleum coke with lignocellulosic biomass components offers a promising route for the high-value utilization of petroleum-refining by-products and sustainable biomass conversion. This study employs coupled Thermogravimetric analysis-Fourier-transform infrared spectroscopy (TGA-FTIR) to systematically examine the co-pyrolysis behaviour and interaction mechanisms between petroleum coke and model lignocellulosic components (cellulose, hemicellulose and lignin) across the temperature range 30–850 °C at heating rates of 5, 10, 15 and 20 °C·min −1 . The results demonstrate that the cellulose–petroleum coke system exhibits optimal volatile-release kinetics at 10 °C·min −1 , with a diffusion coefficient (D = 9.65 × 10 −10 min −2 °C −3 ) and a maximum mass-loss rate (DTG max = −1.47 %·min −1 ). In contrast, the lignin–petroleum coke system shows pronounced synergistic effects at high temperatures (>600 °C), as supported by activation energies of 57.60–84.14 kJ mol −1 and Gibbs free-energy changes (ΔG = 72.23–98.01 kJ mol −1 ), indicating catalytic and flame-retardant potential. Mechanistic insights reveal that lignocellulosic components exert phase-dependent modulation on pyrolysis dynamics, suppressing petroleum-coke hydration, fine-tuning volatile-diffusion kinetics and facilitating graphitization via co-carbonization pathways. These findings provide a scientific basis for the precise engineering of pyrolysis-product characteristics and advance the development of tailored thermochemical conversion strategies.
研究领域:
能源工程
·
化学工程
·
热分析
·
可持续能源
·
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）