CHEMICAL ENGINEERING SCIENCE
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2026
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IF 5.1
Zeyu Niu,Xin Huang,Tianlong Liu,Yunlin Shao,Chuan Ma,Jingyu Ran
Hemicellulose and lignin decreased the activation energy of cellulose pyrolysis by 36.7 and 22.6 kJ/mol. • Hemicellulose interacted cellulose decreased levoglucosan yield by up to 34-fold due to volatile-acid scission. • Lignin interacted cellulose enhanced levoglucosan yield by up to 77% due to thermal ejection and radical stabilization. Understanding the interactions between biomass components during pyrolysis is crucial for product control. Here, we employed a selective graded decoupling strategy to construct cellulose-hemicellulose (C-H) and cellulose-lignin (C-L) binary systems with varying ratios from pine as a typical woody biomass. Fractionation altered sample morphology from dense to porous, yet cellulose I crystallinity was retained in all samples. The effects of varying hemicellulose and lignin contents on cellulose pyrolysis were studied by thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TG-FTIR), pyrolysis–gas chromatography/mass spectrometry (Py-GC/MS), and kinetic analysis. The distributed activation energy model (DAEM) study showed that interactions with hemicellulose and lignin decreased the activation energy of cellulose pyrolysis by 36.7 and 22.6 kJ/mol, respectively. C-H interaction promoted the early evolution of CO 2 and carbonyl compounds, whereas C-L interaction enhanced the release of aromatic phenols while inhibiting the generation of hydrocarbons. C-H interaction drastically reduced levoglucosan (LGA) yield by up to 34-fold and shifted products toward small oxygenates possibly due to the random bond scission catalyzed by hemicellulose-derived acidic volatiles. In contrast, C-L interaction increased the yields of LGA and phenolic compounds by 77% and 70%, respectively. The increase in LGA may be due to a lignin-induced thermal ejection effect that facilitates its rapid escape, while the phenolic enrichment may involve radical stabilization by cellulose-derived hydrogen donors. This study reveals the distinct effects of hemicellulose and lignin on cellulose pyrolysis with biomass, providing a theoretical basis for selective valorization of lignocellulosic biomass. Download: Download high-res image (162KB) Download: Download full-size image
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高影响因子
FUEL
·
2023
·
IF 7.4
Jiangtao Meng,Jing Wang,Fengling Yang,Fangqin Cheng
The multiple influence mechanisms of Fe 2 O 3 on nitrogen evolution during sewage sludge pyrolysis were systematically investigated by correlating temperatures. The results showed that Fe 2 O 3 promoted the pyrolysis of the sludge. The activation energy of the pyrolysis was reduced by 12–110 kJ/mol. Fe 2 O 3 acted oxidatively on sludge nitrogen in the following order Fe 2 O 3 →Fe 3 O 4 ( ca. 528 K)→Fe x N y ( ca. 763 K)→Fe x C ( ca. 1023 K). The oxidation target of Fe 2 O 3 on nitrogen containing compounds varied as a function of temperature. At temperatures of 528 K and 623 K, Fe 2 O 3 hindered the deamination of proteins in char to NH 3 , facilitated the condensation of pyridines to nitrile, and impeded the generation of HCN. At temperatures of 763 K and 1023 K, Fe 2 O 3 facilitated the cleavage of amines, heterocycles, and nitrile in char. Additionally, it promoted the breaking of chains and cyclization of long chain amines in tar. This process theoretically leads to the production of a great amount of NH 3 and HCN at the front. Overall, Fe 2 O 3 inhibited the release of NOx precursors through inhibition of deamination, fixation of nitrogen in char and consumption of NH 3 and HCN. This study will establish the effect mechanism of action of Fe 2 O 3 on the nitrogen conversion of sewage sludge pyrolysis at relevant temperatures. It will provide a theoretical foundation for controlling NOx and the targeted regulation NH 3 (carbon-free hydrogen energy carriers) in the high-value conversion of nitrogen-rich biomass.
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高影响因子
FUEL
·
2023
·
IF 7.4
Yujun Ma,Wenliang Wang,Yishuai Fu,Hui Miao,Jiale Huang,Sizhe Han,Yutong Chen
Improving the yield of the target product of monocyclic aromatic hydrocarbons plays an important role in increasing the economic competitiveness of biomass and waste plastics. In this study, a 3D SiC@HZSM-5@CoFe 2 O 4 multifunctional catalyst with high microwave absorptivity and excellent catalysis was successfully fabricated by a “coating-coating” method. Results showed that the obtained SiC@HZSM-5@CoFe 2 O 4 catalyst had a stable porous structure, abundant oxygen vacancy defects, high specific surface area, good dielectric loss performance, and magnetic loss performance. Encouragingly, co-pyrolysis of corncob (CC) and polystyrene (PS) revealed that the catalyst significantly promoted the synergistic effect and improved the selectivity of renewable gasoline-range aromatics (47.2 area %). In addition, finite element simulations indicated that the prepared catalyst with high microwave absorptivity could effectively accelerate the mass and heat transfer, thereby facilitating the cracking and conversion of pyrolysis vapors. This work provides an efficient method for the production of renewable gasoline-range aromatics from the mixture of biomass and waste plastics by microwave-assisted co-pyrolysis (MACP).
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Yingying Cai,Aikelaimu Aihemaiti,Yiping Su,Yongqi Sun,Xin Sun,Heng Li,Kezhen Chen,Xuehua Shen,Feng Yan,Fan Qu,Heijin Chen,Zuotai Zhang
In this study, the CO 2 -looping system was firstly attempted to build for exploring the effect of calcium-based (Ca-based) additives on pyrolytic characteristics and products in co-pyrolysis of sewage sludge (SS) and biomass. Then, an innovation method for the consumption of CO 2 (CP CO2 ) evaluation was proposed and carried out in the CO 2 -looping system, in which it was evaluated based on the syngas volume and CO 2 proportion. The results revealed that the addition of CaO and Ca(OH) 2 could significantly improve CP CO2 by 21.2% in the co-pyrolysis of 500 ℃, while the CaCO 3 addition decreased the CP CO2 by 1.0%. Besides, the co-pyrolysis temperature more than 700 ℃ would play more significant role on the CP CO2 than the addition of Ca-based additives. Then the effect of Ca-based types on biochar characteristics was also identified accompanied by the bio-oil composition. Results showed that the CaO and Ca(OH) 2 additives not only increased biochar mass and pH, but also enhanced the dissolved organic carbon content and the variety of dissolved organic matter, and reduced the total HMs content. Meanwhile, it was 15 types of components that was identified in bio-oil by NIST mass spectral library, found that the intensity of heptadecanenitrile and estra-1,3,5(10)-trien-17 beta-ol was influenced by Ca-based additives. Moreover, the CaO and Ca(OH) 2 played important roles for improving the CP CO2 in the CO 2 -looping system, which was further verified by Fact Sage. Finally, the mechanism for the Ca-based additives on CP CO2 was proposed at different co-pyrolysis temperatures. These findings can widen paths for biochar application and development of CO 2 capture materials.
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高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
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2023
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IF 6
Ruizhe Chen,Yongfeng Liu,Chenyang Yin,Long Wang,Lu Zhang,Jinou Song,Hua Sun
To investigate the influence of 1-nitropropane (1-NP) initiator on the pyrolysis of n-hexane ( n -C 6 H 14 ), molecular dynamics (MD) simulations and synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) experiments were used to analyze the pyrolysis processes of n -C 6 H 14 and n -C 6 H 14 with 10 % 1-NP added. ReaxFF MD simulations were used to analyze the pyrolysis rates and product distributions of n -C 6 H 14 and 1-NP/ n -C 6 H 14 at different temperatures. The mechanism of action of n -C 6 H 14 pyrolysis initiated by 1-NP was investigated. Additionally, the pyrolysis products of n -C 6 H 14 and 1-NP/ n -C 6 H 14 were identified and quantitatively analyzed using the SVUV-PIMS technique. These experimental results were compared with the ReaxFF MD simulation results to validate the reliability of the simulations and to complement each other. The results indicate that the presence of 1-NP promotes the pyrolysis of n -C 6 H 14 and significantly improves the chemical heat sink of the fuel. The chemical heat sink in the 1-NP/ n -C 6 H 14 system differs from that in the n -C 6 H 14 system by 28.78 kJ/kg at 2103 K. A significant increase in C 2 H 4 production in the pyrolysis products of n -C 6 H 14 with the addition of 1-NP. The pyrolysis of 1-NP/ n -C 6 H 14 yielded approximately twice as much C 2 H 4 as n -C 6 H 14 at 2103 K. The pyrolysis reactions were described by first-order kinetics, and the activation energy for the pyrolysis of 1-NP/ n -C 6 H 14 was determined to be 140 kJ/mol, approximately 48 % lower than that of n -C 6 H 14 . The composition of the pyrolysis products was confirmed by SVUV-PIMS experiments, which were in good agreement with the ReaxFF MD simulations. The mechanism of pyrolysis of n -C 6 H 14 initiated by 1-NP was elucidated: the NO 2 radicals generated by 1-NP react with H radicals of the system to form OH radicals. The primary reaction of n -C 6 H 14 involves the abstraction of H by OH, leading to the formation of C 6 H 13 . Subsequently, C 6 H 13 is further decomposed to form 1-C 3 H 7 , 1-C 4 H 8 , 1-C 5 H 10 and 2-C 6 H 12 .
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高影响因子
JOURNAL OF THE ENERGY INSTITUTE
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2023
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IF 5.7
Jinchang Liu,Tao Qin,Kuo Li,Xin Chen,Qiuxiang Lu,Jin Deng,Xiaodong Luo,Shenfu Yuan
In this work, the promotion mechanism of Ce as Fe and Ni catalyst promoter for the catalytic reforming of biomass pyrolysis volatiles was investigated. Fe–Ni–Ce/biochar catalysts were prepared and evaluated for their catalytic performance under N 2 and steam atmospheres. The yield of Fe–Ni–Ce/biochar catalyzed syngas (H 2 +CO) increased from 224.36 mL/g to 1299.14 mL/g (800 °C) with the change of N 2 to steam atmosphere. The addition of Ce can introduce a large number of oxygen vacancies to the catalyst, and the increase of oxygen vacancies reduces the reaction barrier of the tar, thus promoting the catalytic activity of the catalyst. In the N 2 atmosphere, the electron transfer of Ce 3+ ⇄ Ce 4+ during catalytic process promotes the production of Fe 2+ to ensure the catalytic activity of the catalyst. In the steam atmosphere, Ni will activate the active sites in a steam atmosphere in water molecules. The activated active sites increase the catalyst activity by cyclic reaction with the oxygen vacancies introduced by Ce, resulting in a higher catalytic capacity of Fe–Ni/biochar than Fe–Ce/biochar. To provide the theoretical basis for the preparation of efficient catalysts based on Fe and Ni.
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高影响因子
CHINESE JOURNAL OF CATALYSIS
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2021
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IF 8.271
Jun-Sheng Jiang,He-Lei Wei,Ai-Dong Tan,Rui Si,Wei-De Zhang,Yu-Xiang Yu
Iron-based single-atom catalysts with nitrogen-doped carbon as support (Fe-SA/NPC) are considered effective alternatives to replace Pt-group metals for scalable application in fuel cells. However, synthesizing high-loading Fe-SA catalysts by a simple procedure remains challenging. Herein, we report a high-loading (7.5 wt%) Fe-SA/NPC catalyst prepared by carbon-assisted pyrolysis of metal complexes. Both the nitrogen-doped porous carbon (NPC) support with high specific surface area and ο -phenylenediamine ( o -PD) play key roles role in the preparation of high-loading Fe-SA/NPC catalysts. The results of X-ray photoelectron spectroscopy, high-angle annular dark-field scanning transmission electron microscopy, and X-ray absorption fine structure spectroscopy experiments show that the Fe atoms are anchored on the carbon carriers in a single-atom site configuration and coordinated with four of the doped nitrogen atoms of the carbon substrates (Fe-N 4 ). The activities of the Fe-SA/NPC catalysts in the oxygen reduction reaction increased with increasing iron loading. The optimized 250Fe-SA/NPC-800 catalyst exhibited an onset potential 0.97 V of and a half-wave potential of 0.85 V. Our study provides a simple approach for the large-scale synthesis of high-loading single-atom catalysts.
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高影响因子
RENEWABLE ENERGY
·
2021
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IF 8.001
Chao Li,Yifan Sun,Zijun Yi,Lijun Zhang,Shu Zhang,Xun Hu
Co-pyrolysis of coke bottle (CB) with sawdust/cellulose/lignin was conducted at 700 °C in this study, aiming to understand the potential influence of interactions of the volatiles of the varied origins on properties of the char. The results indicated that the interaction of volatiles from CB with that from biomass enhanced cross-polymerization of the volatiles, decreasing the formation of gases while enhanced the formation of both char and oil. The cross-interactions of the intermediates also diminished the formation of π-conjugated organics. In addition, the varied volatiles from the pyrolysis of cellulose , lignin, or sawdust interacted with that from CB and affected the properties of char in different ways. The char from the co-pyrolysis of sawdust/CB was more aliphatic, and had a higher oxygen content (7.3%) and higher polarity but lower thermal stability. Additionally, the thermal stability, crystallinity as well as the evolution of functionalities of char versus increasing temperature were also significantly affected by the cross-interactions of the volatiles.
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高影响因子
Sustainability
·
2021
·Vol. 13
·期 5
·2641
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IF 3.251
Siyao Bian,Shuang Xu,Zhibing Yin,Sen Liu,Jihui Li,Shuying Xu,Yucang Zhang
In this study, sequential KMnO4-promoted oxidative pyrolysis and H2O2oxidation were employed to upgrade the adsorption capacities of durian shell biochar for methylene blue (MB) and tetracycline (TC) in an aqueous solution. It was found that the KMnO4/H2O2co-modification was greatly influenced by pyrolysis temperature and the optimal temperature was 300 °C. Moreover, a low concentration of H2O2enabled the improvement of the adsorption capabilities greatly with the catalysis of pre-impregnated manganese oxides, addressing the shortcoming of single H2O2modification. The co-modified biochar exhibited high adsorption capabilities for MB and TC, remarkably surpassed KMnO4- and H2O2- modified biochars as well as pristine biochar. The increase of adsorption capabilities could be mainly contributed to the incorporation of MnOxand carboxyl by KMnO4-promoted oxidative decomposition and Mn-catalyzed H2O2oxidation. This would provide a novel and efficient method for preparing highly adsorptive biochar using sequential KMnO4-promoted oxidative pyrolysis and H2O2oxidation.Keywords:biochar;KMnO4/H2O2co-modification;methylene blue;tetracycline
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2021
·Vol. 45
·期 13
·5949-5957
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IF 3.591
Xuexia Liu,Shuaihui Li,Limin Liu,Zhijun Wang
The development of active and stable carbon nanomaterials as electrocatalysts for the oxygen reduction reaction (ORR) remains a significant challenge. Herein, we report a one-step pyrolysis process to design hierarchical micro/mesoporous N-doped carbon (m-NC) materials using low-cost folic acid precursors. The optimal m-NC material carbonized at 750 °C (m-NC-750) displays a splendid ORR electrocatalytic activity and perfect stability in an alkaline medium (0.1 mol L−1 KOH). Notably, the current density of m-NC-750 can reach 4.35 mA cm−2 at 0.85 V, which surpasses that of commercial Pt/C (20 wt%). The higher electrocatalytic activity and activation of oxygen is due to the porous structures facilitating ion diffusion and the graphitic N dopant providing more active sites. In addition, the graphite N dopant of the m-NC material possesses the lowest energy barrier of reactions based on density functional theory (DFT) calculations, which effectively boosts the ORR of the as-prepared materials. This simple and economical method provides a facile way of designing high-performance carbon electrocatalysts for the ORR.
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高影响因子
BIORESOURCE TECHNOLOGY
·
2021
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IF 9.642
Yicong Chen,Jianting Liu,Qibin Zeng,Zuxue Liang,Xiaoxia Ye,Yuancai Lv,Minghua Liu
In this study, the sulfonic group was introduced to prepare high-performance Eucommia ulmoides lignin-based biochar, which was used to remove tetracycline hydrochloride. The BET area (2008 m 2 g −1 ) of sulfonated biochar was twice that of unmodified biochar. Through XRD and Raman analysis, the synergetic pyrolysis mechanism of the sulfonic group in the formation of the porous structure was discussed. Sulfonated biochar had excellent adsorption performance for tetracycline hydrochloride (Q m : 1163 mg g −1 ), while the adsorption performance of unmodified biochar was about only one-fourth (Q m : 277.7 mg g −1 ) of that. The adsorption of tetracycline hydrochloride by the sulfonated biochar was spontaneously endothermic and conformed to the Langmuir isotherm model. The adsorption process was confirmed by pseudo-second-order kinetic model. Moreover, the sulfonic group on the sulfonated biochar significantly promoted the formation of the hydrogen bond and greatly improved the adsorption performance.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Yutong Luo,Jiaheng Qin,Guangxue Yang,Sha Luo,Ziming Zhao,Ming Chen,Jiantai Ma
The rational design and fabrication of distinctive coordination sites is an attractive and challenging approach to develop electrocatalysts with superior activity toward oxygen evolution reaction (OER). Constructing N-doped carbon shells coordinated with transitional metal composites can greatly enhance the OER activity of electrocatalysts. Herein, a facile electrochemical-pyrolysis strategy is applied to synthesize NiS/C 3 N 4 composite with N-Ni-S coordination sites by in-situ crystallization on copper foam (CF). A detailed characterization, especially synchrotron-based X-ray absorption fine structure (XAFS) clearly unravels the N-Ni-S coordination mode is successfully formed. As a result, NiS/C 3 N 4 presents excellent OER performance with a low overpotential of 334 mV at a current density of 10 mA cm −2 , a Tafel slope of 45 mV dec −1 , and robust electrochemical stability for 50 h in basic media, outperforming some recently reported conventional transitional metal electrocatalysts. The outstanding electrocatalytic performance of NiS/C 3 N 4 mainly originates from the N-Ni-S coordination sites, which can provide abundant catalytic active sites, facilitate charge transfer, and enhance electronic conductivity. Furthermore, by tuning the two important experimental parameters of electrodeposition potential and electropolymerization time, the relationship between morphology and electrocatalytic performance of catalysts is deeply explored. This work demonstrates the validity of improving electrocatalytic performance by elaborately tailoring the coordination sites, thereby opening up an applicable and inspiring avenue forward in the design of advanced electrocatalysts for water splitting.
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高影响因子
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