Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106789
Jiaqi Tian , Hao Zhu , Ruizhi Li , Guobiao Cai
Hydroxyl-terminated polybutadiene (HTPB) is widely utilized in solid and hybrid rocket propellants due to its mechanical properties and combustion performance. Insight into its pyrolysis process is key to enhancing combustion efficiency in rocket engines. This study employs ReaxFF molecular dynamics (MD) simulations to explore the pyrolysis mechanism of HTPB under extreme conditions, with temperatures ranging from 1000 K to 2000 K. The results identify the primary degradation products and elucidate their formation mechanisms. The simulation reveals that C-C bond cleavage at polymerization sites is the initial step, followed by the formation of linear oligomers and butadiene. Subsequent reactions, including hydrogenation and dehydrogenation, lead to the generation of smaller molecular species. The kinetic analysis confirms that HTPB pyrolysis follows first-order reaction kinetics, with an activation energy of 8.12 kcal/mol. The findings are compared with existing experimental data, highlighting the influence of thermal environments on pyrolysis mechanisms and product distributions.
羟基封端聚丁二烯（HTPB）因其机械性能和燃烧性能而被广泛用于固体和混合火箭推进剂。深入了解其热解过程是提高火箭发动机燃烧效率的关键。本研究采用 ReaxFF 分子动力学（MD）模拟来探索 HTPB 在 1000 K 至 2000 K 极端条件下的热解机理。结果确定了主要降解产物，并阐明了其形成机制。模拟结果表明，聚合点的 C-C 键裂解是第一步，随后形成线性低聚物和丁二烯。随后的反应，包括氢化和脱氢，导致生成更小的分子种类。动力学分析证实 HTPB 热解遵循一阶反应动力学，活化能为 8.12 kcal/mol。研究结果与现有实验数据进行了比较，突出了热环境对热解机制和产物分布的影响。
{"title":"Insight into HTPB pyrolysis mechanism under high-temperature: A reactive molecular dynamics study","authors":"Jiaqi Tian , Hao Zhu , Ruizhi Li , Guobiao Cai","doi":"10.1016/j.jaap.2024.106789","DOIUrl":"10.1016/j.jaap.2024.106789","url":null,"abstract":"<div><div>Hydroxyl-terminated polybutadiene (HTPB) is widely utilized in solid and hybrid rocket propellants due to its mechanical properties and combustion performance. Insight into its pyrolysis process is key to enhancing combustion efficiency in rocket engines. This study employs ReaxFF molecular dynamics (MD) simulations to explore the pyrolysis mechanism of HTPB under extreme conditions, with temperatures ranging from 1000 K to 2000 K. The results identify the primary degradation products and elucidate their formation mechanisms. The simulation reveals that C-C bond cleavage at polymerization sites is the initial step, followed by the formation of linear oligomers and butadiene. Subsequent reactions, including hydrogenation and dehydrogenation, lead to the generation of smaller molecular species. The kinetic analysis confirms that HTPB pyrolysis follows first-order reaction kinetics, with an activation energy of 8.12 kcal/mol. The findings are compared with existing experimental data, highlighting the influence of thermal environments on pyrolysis mechanisms and product distributions.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106789"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425787","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106778
H.T. Lin , A.D.K. Wibowo , T.F. Wang , H.H. Chiu , W.Y. Hsu , A.N. Huang , H.P. Kuo
The heat transfer characteristics of non-pretreated rice husk pyrolysis in a fluidized bed with alumina beads (500 μm - 590 μm) as bed material are studied. Assuming instantaneous heating of biomass to the reaction temperature, the effective overall heat transfer coefficient of the system (UA) is initially calculated based on the compositions of the collected products and reaction temperature. UA ranges from 0.82 to 2.95 W/K. This heat transfer coefficient study allows ad hoc product distributions to be predicted from theoretical bases. The effects of the biomass feeding rate (F) and the bed height (H/D) on UA values are also analyzed. Highest UA and specific heat of the pyrolysis reaction of −3.35 MJ/kg are found at F = 5 g/min and H/D = 1.0, where H/D is the largest and F is the lowest in the range studied. Upon feeding of the low thermal conductivity biomass, UA typically decreases. However, if the bed materials are limited, the fed biomass and its produced char act as an auxiliary heating medium to improve the effective heat transfer coefficient. High UA improves the efficiency of the pyrolysis reaction, but it decreases the bio-oil fraction in the product due to secondary decomposition.
研究了以氧化铝珠（500 μm - 590 μm）为床层材料的流化床中未经预处理的稻壳热解的传热特性。假设生物质瞬时加热到反应温度，根据收集的产物成分和反应温度初步计算出系统的有效总传热系数（UA）。UA 在 0.82 到 2.95 W/K 之间。通过对传热系数的研究，可以根据理论基础预测特定的产品分布。此外，还分析了生物质进料速率（F）和床层高度（H/D）对 UA 值的影响。在 F = 5 g/min 和 H/D = 1.0 时，热解反应的最高 UA 和比热为 -3.35 MJ/kg，其中 H/D 在研究范围内最大，F 最低。加入低导热性生物质后，UA 通常会降低。但是，如果床层材料有限，进料生物质及其产生的焦炭可作为辅助加热介质，提高有效传热系数。高 UA 可以提高热解反应的效率，但会因二次分解而降低产品中的生物油部分。
{"title":"A new approach to evaluate the overall heat transfer coefficient of a fluidized bed biomass pyrolyzer","authors":"H.T. Lin , A.D.K. Wibowo , T.F. Wang , H.H. Chiu , W.Y. Hsu , A.N. Huang , H.P. Kuo","doi":"10.1016/j.jaap.2024.106778","DOIUrl":"10.1016/j.jaap.2024.106778","url":null,"abstract":"<div><div>The heat transfer characteristics of non-pretreated rice husk pyrolysis in a fluidized bed with alumina beads (500 μm - 590 μm) as bed material are studied. Assuming instantaneous heating of biomass to the reaction temperature, the effective overall heat transfer coefficient of the system (UA) is initially calculated based on the compositions of the collected products and reaction temperature. UA ranges from 0.82 to 2.95 W/K. This heat transfer coefficient study allows <em>ad hoc</em> product distributions to be predicted from theoretical bases. The effects of the biomass feeding rate (F) and the bed height (H/D) on UA values are also analyzed. Highest UA and specific heat of the pyrolysis reaction of −3.35 MJ/kg are found at F = 5 g/min and H/D = 1.0, where H/D is the largest and F is the lowest in the range studied. Upon feeding of the low thermal conductivity biomass, UA typically decreases. However, if the bed materials are limited, the fed biomass and its produced char act as an auxiliary heating medium to improve the effective heat transfer coefficient. High UA improves the efficiency of the pyrolysis reaction, but it decreases the bio-oil fraction in the product due to secondary decomposition.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106778"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106799
Vanessa Ramos do Nascimento , Mariangela Bruch dos Santos , Lisiane Diehl , José Neri Gottfried Paniz , Fernanda de Castilhos , Cezar Augusto Bizzi
In this work a pyrolysis system heated by microwave radiation (microwave-assisted pyrolysis, MAP) was developed to produce bio-oil, biochar, and biogas using pine wood residue as feedstock. For this purpose, a multimode microwave cavity was modified to allocate a quartz reactor used for pyrolysis. Some pieces of SiC were used as microwave absorbent material, which were placed externally to the quartz reactor (non-premixed approach), allowing a fast heating rate and cooling down the reactor. After assembling the system, the performance of the proposed MAP approach was investigated through the microwave irradiation time (10, 15, and 20 min) and the temperature of the process (500, 600, and 700 °C). The best results were obtained with 500 °C and a total process time of 10 min, which produced 65 %, 33 %, and 2 % of bio-oil, biochar, and biogas, respectively. Higher temperatures (600 or 700 ºC) resulted in an oily phase with higher acidity, besides a non-significant increment in the yields. The yields obtained using the proposed MAP approach were compared with those obtained using conventional pyrolysis (47 %, 32 %, and 21 % of bio-oil, biochar, and biogas, respectively). The biochar produced by MAP presented a high heating value (HHV) of 26 MJ/kg. As the main advantages of the proposed MAP approach, it is possible to highlight the shorter pyrolysis time, faster heating and cooling rates, no feedstock pretreatment before pyrolysis, nor the use of catalysts, and it was considered a clean source of production of bioproducts.
{"title":"Microwave-assisted pyrolysis of pine wood waste: system development, biofuels production, and characterization","authors":"Vanessa Ramos do Nascimento , Mariangela Bruch dos Santos , Lisiane Diehl , José Neri Gottfried Paniz , Fernanda de Castilhos , Cezar Augusto Bizzi","doi":"10.1016/j.jaap.2024.106799","DOIUrl":"10.1016/j.jaap.2024.106799","url":null,"abstract":"<div><div>In this work a pyrolysis system heated by microwave radiation (microwave-assisted pyrolysis, MAP) was developed to produce bio-oil, biochar, and biogas using pine wood residue as feedstock. For this purpose, a multimode microwave cavity was modified to allocate a quartz reactor used for pyrolysis. Some pieces of SiC were used as microwave absorbent material, which were placed externally to the quartz reactor (non-premixed approach), allowing a fast heating rate and cooling down the reactor. After assembling the system, the performance of the proposed MAP approach was investigated through the microwave irradiation time (10, 15, and 20 min) and the temperature of the process (500, 600, and 700 °C). The best results were obtained with 500 °C and a total process time of 10 min, which produced 65 %, 33 %, and 2 % of bio-oil, biochar, and biogas, respectively. Higher temperatures (600 or 700 ºC) resulted in an oily phase with higher acidity, besides a non-significant increment in the yields. The yields obtained using the proposed MAP approach were compared with those obtained using conventional pyrolysis (47 %, 32 %, and 21 % of bio-oil, biochar, and biogas, respectively). The biochar produced by MAP presented a high heating value (HHV) of 26 MJ/kg. As the main advantages of the proposed MAP approach, it is possible to highlight the shorter pyrolysis time, faster heating and cooling rates, no feedstock pretreatment before pyrolysis, nor the use of catalysts, and it was considered a clean source of production of bioproducts.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106799"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106812
Haibin Guan , Qinghe Bao , Liangbei Liu , Baofeng Zhao , Cunqing Zhong , Bari Wulan , Suxiang Liu , Xinru Qian , Di Zhu , Xiangyu Feng
Antibiotic mycorrhizal residues (AMR) are valuable organic wastes but have become a significant environmental and economic challenge due to their potentially hazardous nature and high treatment costs. In this study, an environmentally friendly and low-cost in situ nitrogen-doped porous carbon material was successfully prepared by hydrothermal carbonisation combined with KOH activation for efficient CO2 capture. The obtained material was systematically characterized and tested, and its physical and chemical properties were analyzed. By adjusting the activation temperature from 600 to 800 °C, the prepared porous carbon materials exhibited different specific surface areas (648.41–1712.72 m²/g), pore volumes (0.310–0.879 cm³/g), and the nitrogen was uniformly distributed in the carbon skeleton. The optimal N-doped porous carbon demonstrated the adsorption capacities of 3.99 mmol g−1 at 25 ℃ and 5.35 mmol g−1 at 0 ℃ under 1 bar. In addition, the prepared adsorbents exhibited excellent CO2/N2 selectivity, high isosteric heat, and good cyclic stability. These excellent CO2 adsorption properties were attributed to the highly developed microporous structure of the materials and the uniformly distributed nitrogen functional groups in the carbon skeleton. Overall, the results highlight the great potential of this class of heteroatom-doped novel carbon materials as selective CO2 adsorbents, providing a practical way to seek efficient CO2 abatement solutions.
{"title":"Preparation of porous carbon from hydrothermal treatment products of modified antibiotic mycelial residues and its use in CO2 capture","authors":"Haibin Guan , Qinghe Bao , Liangbei Liu , Baofeng Zhao , Cunqing Zhong , Bari Wulan , Suxiang Liu , Xinru Qian , Di Zhu , Xiangyu Feng","doi":"10.1016/j.jaap.2024.106812","DOIUrl":"10.1016/j.jaap.2024.106812","url":null,"abstract":"<div><div>Antibiotic mycorrhizal residues (AMR) are valuable organic wastes but have become a significant environmental and economic challenge due to their potentially hazardous nature and high treatment costs. In this study, an environmentally friendly and low-cost in situ nitrogen-doped porous carbon material was successfully prepared by hydrothermal carbonisation combined with KOH activation for efficient CO<sub>2</sub> capture. The obtained material was systematically characterized and tested, and its physical and chemical properties were analyzed. By adjusting the activation temperature from 600 to 800 °C, the prepared porous carbon materials exhibited different specific surface areas (648.41–1712.72 m²/g), pore volumes (0.310–0.879 cm³/g), and the nitrogen was uniformly distributed in the carbon skeleton. The optimal N-doped porous carbon demonstrated the adsorption capacities of 3.99 mmol g<sup>−1</sup> at 25 ℃ and 5.35 mmol g<sup>−1</sup> at 0 ℃ under 1 bar. In addition, the prepared adsorbents exhibited excellent CO<sub>2</sub>/N<sub>2</sub> selectivity, high isosteric heat, and good cyclic stability. These excellent CO<sub>2</sub> adsorption properties were attributed to the highly developed microporous structure of the materials and the uniformly distributed nitrogen functional groups in the carbon skeleton. Overall, the results highlight the great potential of this class of heteroatom-doped novel carbon materials as selective CO<sub>2</sub> adsorbents, providing a practical way to seek efficient CO<sub>2</sub> abatement solutions.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106812"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142444665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106814
Shan Zhong , Hao Xu , Xiaojun Zheng , Guanlin Li , Shuang Wang
Given the harm caused by invasive plants to the environment and the high cost of treatment, we propose high-value transformation and utilization for invasive plants. Highly porous carbon derived from invasive plant (Canada goldenrod) was successfully synthesized through a feasible and green carbonization approach, which was firstly utilized as supercapacitor electrode. It is found that the addition of nitrogen (N)-rich chlorella could positively increase the N content and considerably boost the specific surface area up to 2231.41 m2 g−1 for the resultant Carbon-GC1-800, which are crucial factors for accelerating the ion transport and improving the capacitive behaviors. Notably, Carbon-GC1-800 exhibits the highest ratio (70.9 %) of microporous volume to total pore volume. The electrochemical properties of Carbon-GC1-800 electrode exhibits an outstanding specific capacitance of 388.2 F g−1 at a current density of 0.5 A g−1 and a superb rate capability of 75.7 % from 0.5 A g−1 to 10 A g−1. The assembled symmetric supercapacitor with ionic liquid as electrolyte demonstrates the exceptional maximum power density of 8753.7 W kg−1 and peak energy density of 59.3 Wh kg−1. This study presents the novel ideas and effective techniques to produce porous carbons for energy storage from invasive plant resources.
鉴于入侵植物对环境造成的危害和高昂的处理成本，我们提出了对入侵植物进行高价值转化和利用的建议。通过一种可行的绿色碳化方法，成功合成了从入侵植物（加拿大金线莲）中提取的高多孔碳，并首次将其用作超级电容器电极。研究发现，添加富氮（N）小球藻可积极增加 N 含量，并显著提高碳-GC1-800 的比表面积，使其达到 2231.41 m2 g-1，这是加速离子传输和改善电容行为的关键因素。值得注意的是，Carbon-GC1-800 的微孔体积与总孔隙体积之比最高（70.9%）。CarbonGC1-800 电极的电化学特性显示，在电流密度为 0.5 A g-1 时，其比电容高达 388.2 F g-1，在 0.5 A g-1 至 10 A g-1 的范围内，其速率能力高达 75.7%。以离子液体为电解质组装的对称超级电容器的最大功率密度为 8753.7 W kg-1，峰值能量密度为 59.3 Wh kg-1。本研究提出了利用入侵植物资源生产多孔碳储能器的新思路和有效技术。
{"title":"High-value conversion of invasive plant into nitrogen-doped porous carbons for high-performance supercapacitors","authors":"Shan Zhong , Hao Xu , Xiaojun Zheng , Guanlin Li , Shuang Wang","doi":"10.1016/j.jaap.2024.106814","DOIUrl":"10.1016/j.jaap.2024.106814","url":null,"abstract":"<div><div>Given the harm caused by invasive plants to the environment and the high cost of treatment, we propose high-value transformation and utilization for invasive plants. Highly porous carbon derived from invasive plant (Canada goldenrod) was successfully synthesized through a feasible and green carbonization approach, which was firstly utilized as supercapacitor electrode. It is found that the addition of nitrogen (N)-rich chlorella could positively increase the N content and considerably boost the specific surface area up to 2231.41 m<sup>2</sup> g<sup>−1</sup> for the resultant Carbon-GC<sub>1</sub>-800, which are crucial factors for accelerating the ion transport and improving the capacitive behaviors. Notably, Carbon-GC<sub>1</sub>-800 exhibits the highest ratio (70.9 %) of microporous volume to total pore volume. The electrochemical properties of Carbon-GC<sub>1</sub>-800 electrode exhibits an outstanding specific capacitance of 388.2 F g<sup>−1</sup> at a current density of 0.5 A g<sup>−1</sup> and a superb rate capability of 75.7 % from 0.5 A g<sup>−1</sup> to 10 A g<sup>−1</sup>. The assembled symmetric supercapacitor with ionic liquid as electrolyte demonstrates the exceptional maximum power density of 8753.7 W kg<sup>−1</sup> and peak energy density of 59.3 Wh kg<sup>−1</sup>. This study presents the novel ideas and effective techniques to produce porous carbons for energy storage from invasive plant resources.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106814"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106828
Neng T.U. Culsum , Agus Kismanto , Prima Zuldian , Nina K. Supriatna , Samdi Yarsono , Lan M.T. Nainggolan , Alfonsus A. Raksodewanto , Oni Fariza , Fahruddin J. Ermada , Dea G.D. Saribu , Munawar Khalil , Grandprix T.M. Kadja
Excessive plastic consumption has enormous environmental consequences, including global climate change, the accumulation of non-biodegradable substances, and the depletion of fossil fuel resources. Accordingly, sustainable treatment of waste plastics must be prioritized to achieve a greener world while generating valuable energy products. Pyrolysis has been proven to be an environmentally friendly strategy for recycling plastic waste. In addition, the employment of catalysts in the pyrolysis process, particularly base catalysts, can improve the quality of the products. Base catalysts are highly selective for the formation of alkenes and aromatic hydrocarbons. In addition, the basicity of the catalyst can influence the pyrolysis products. Catalysts with lower basicity promote the formation of aldehydes and ketones, whereas catalysts with strong basicity can encourage hydrocarbon production. In addition, base catalysts can enhance the quality of pyrolytic oil by decarboxylating acidic compounds. Accordingly, this review focuses on the pyrolysis of plastic waste by employing base catalysts. The correlation between catalyst features and catalytic activity in the pyrolysis of plastic waste was also emphasized.
{"title":"An overview of catalytic pyrolysis of plastic waste over base catalysts","authors":"Neng T.U. Culsum , Agus Kismanto , Prima Zuldian , Nina K. Supriatna , Samdi Yarsono , Lan M.T. Nainggolan , Alfonsus A. Raksodewanto , Oni Fariza , Fahruddin J. Ermada , Dea G.D. Saribu , Munawar Khalil , Grandprix T.M. Kadja","doi":"10.1016/j.jaap.2024.106828","DOIUrl":"10.1016/j.jaap.2024.106828","url":null,"abstract":"<div><div>Excessive plastic consumption has enormous environmental consequences, including global climate change, the accumulation of non-biodegradable substances, and the depletion of fossil fuel resources. Accordingly, sustainable treatment of waste plastics must be prioritized to achieve a greener world while generating valuable energy products. Pyrolysis has been proven to be an environmentally friendly strategy for recycling plastic waste. In addition, the employment of catalysts in the pyrolysis process, particularly base catalysts, can improve the quality of the products. Base catalysts are highly selective for the formation of alkenes and aromatic hydrocarbons. In addition, the basicity of the catalyst can influence the pyrolysis products. Catalysts with lower basicity promote the formation of aldehydes and ketones, whereas catalysts with strong basicity can encourage hydrocarbon production. In addition, base catalysts can enhance the quality of pyrolytic oil by decarboxylating acidic compounds. Accordingly, this review focuses on the pyrolysis of plastic waste by employing base catalysts. The correlation between catalyst features and catalytic activity in the pyrolysis of plastic waste was also emphasized.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106828"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106807
Jiaomei Liu , Xiangfei Xue , Yunan Yang , Jie Liang
Core–shell zeolites have been used to improve bio-oil quality in biomass catalytic fast pyrolysis (CFP), yet research on shell materials remains limited. This study explores ZSM-5@MCM-41 and ZSM-5@SBA-15 core–shell micro/mesoporous zeolites, including their Al-containing variants synthesized with sodium aluminate (SA), aluminum sulfate (AS), and aluminum isopropoxide (AI) as Al sources, for improving bio-oil quality during biomass CFP. The samples were thoroughly characterized using powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption, and NH3-TPD techniques. CFP experiments using jujube sawdust examined the impact of mesoporous structure and Al sources on bio-oil yield and quality. Results indicated that ZSM-5@MCM-41, with a smaller mesoporous structure and higher acid strength, showed 1.7 times greater hydrocarbon selectivity compared to ZSM-5@SBA-15 (20.6 % vs. 12.4 % by area). The incorporation of Al into the MCM-41 shell led to a decrease in bio-oil yield, with the order being ZSM-5@MCM-41 > ZSM-5@MCM-41-AI > ZSM-5@MCM-41-AS > ZSM-5@MCM-41-SA, owing to the combined effects of strong acid sites and mesoporosity. However, the hydrocarbon selectivity of ZSM-5@Al-MCM-41 catalysts decreased by 15.6–19.5 % owing to reduced mesoporous volume. Conversely, while the incorporation of Al in the SBA-15 shell also reduced bio-oil yield, it increased hydrocarbon production by 27.0–47.6 %. Also, the hydrocarbons selectivity was related to the acid strength of the ZSM-5@Al-SBA-15 catalysts, demonstrating that strong acid sites are more effective in regulating bio-oil quality than porosity.
{"title":"Catalytic fast pyrolysis of jujube sawdust over two core–shell micro/mesoporous zeolites: Impact of mesoporous structure and aluminum sources","authors":"Jiaomei Liu , Xiangfei Xue , Yunan Yang , Jie Liang","doi":"10.1016/j.jaap.2024.106807","DOIUrl":"10.1016/j.jaap.2024.106807","url":null,"abstract":"<div><div>Core–shell zeolites have been used to improve bio-oil quality in biomass catalytic fast pyrolysis (CFP), yet research on shell materials remains limited. This study explores ZSM-5@MCM-41 and ZSM-5@SBA-15 core–shell micro/mesoporous zeolites, including their Al-containing variants synthesized with sodium aluminate (SA), aluminum sulfate (AS), and aluminum isopropoxide (AI) as Al sources, for improving bio-oil quality during biomass CFP. The samples were thoroughly characterized using powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, N<sub>2</sub> adsorption–desorption, and NH<sub>3</sub>-TPD techniques. CFP experiments using jujube sawdust examined the impact of mesoporous structure and Al sources on bio-oil yield and quality. Results indicated that ZSM-5@MCM-41, with a smaller mesoporous structure and higher acid strength, showed 1.7 times greater hydrocarbon selectivity compared to ZSM-5@SBA-15 (20.6 % vs. 12.4 % by area). The incorporation of Al into the MCM-41 shell led to a decrease in bio-oil yield, with the order being ZSM-5@MCM-41 > ZSM-5@MCM-41-AI > ZSM-5@MCM-41-AS > ZSM-5@MCM-41-SA, owing to the combined effects of strong acid sites and mesoporosity. However, the hydrocarbon selectivity of ZSM-5@Al-MCM-41 catalysts decreased by 15.6–19.5 % owing to reduced mesoporous volume. Conversely, while the incorporation of Al in the SBA-15 shell also reduced bio-oil yield, it increased hydrocarbon production by 27.0–47.6 %. Also, the hydrocarbons selectivity was related to the acid strength of the ZSM-5@Al-SBA-15 catalysts, demonstrating that strong acid sites are more effective in regulating bio-oil quality than porosity.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106807"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142425737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106819
Wei Wang, Zhaoping Zhong, Xiang Zheng, Qihang Ye, Yihui Li, Yuxuan Yang
Hydrolyzed lignin (HL), one kind of organic solid wastes, comes from the production of hydrolysis of lignocellulosic biomass for high-value chemicals, unsuitable treatment of which not only meaning the waste of resources but also resulting environmental pollution. The pyrolysis of HL has the problem of high oxygen-containing compounds and low hydrocarbons in the products. The HZSM-5/MCM-41 (HM) meso-microporous composite catalyst, containing nickel and molybdenum, was synthesized through impregnation to enhance the production of monocyclic aromatic hydrocarbons (MAHs) during the in-situ catalytic pyrolysis of hydrolyzed lignin. Different transition metals loaded on composite molecular sieves were prepared for comparison. The relationship between catalyst structure and pyrolysis efficiency was studied based on characterization techniques including SEM, BET, and XRD. This study investigated the catalytic properties of modified composite molecular sieves with Ni and Mo at different loaded ratios on the pyrolysis of hydrolyzed lignin. Results indicated that HM loaded with different metals had different catalytic pyrolysis selectivity. The relative yield of MAHs on 3 %Ni-HM was the highest, at 27.78 %, while that of phenolic on 5 %Mo-HM was 51.02 %. Thus, by modifying the co-loading ratios between Ni and Mo, the combined catalytic pyrolysis of hydrolyzed lignin was performed, achieving a 39.24 % yield of MAHs on the catalyst Mo1Ni2-HM, markedly surpassing the 17.69 % yield from unaltered HZSM-5/MCM-41. In addition, the improvement of active sites was caused by transition metals loaded and the synergistic effect between bimetals enhanced the catalytic activity and stability. HZSM-5/MCM-41 loaded with metal oxides promoted the depolymerization of macromolecules in the intermediate products of pyrolysis, and thus improved the relative yield of MAHs among pyrolysis products of hydrolyzed lignin.
{"title":"Catalytic pyrolysis of hydrolyzed lignin using HZSM-5/MCM-41 supported transition-metal to produce monocyclic aromatic hydrocarbons","authors":"Wei Wang, Zhaoping Zhong, Xiang Zheng, Qihang Ye, Yihui Li, Yuxuan Yang","doi":"10.1016/j.jaap.2024.106819","DOIUrl":"10.1016/j.jaap.2024.106819","url":null,"abstract":"<div><div>Hydrolyzed lignin (HL), one kind of organic solid wastes, comes from the production of hydrolysis of lignocellulosic biomass for high-value chemicals, unsuitable treatment of which not only meaning the waste of resources but also resulting environmental pollution. The pyrolysis of HL has the problem of high oxygen-containing compounds and low hydrocarbons in the products. The HZSM-5/MCM-41 (HM) meso-microporous composite catalyst, containing nickel and molybdenum, was synthesized through impregnation to enhance the production of monocyclic aromatic hydrocarbons (MAHs) during the in-situ catalytic pyrolysis of hydrolyzed lignin. Different transition metals loaded on composite molecular sieves were prepared for comparison. The relationship between catalyst structure and pyrolysis efficiency was studied based on characterization techniques including SEM, BET, and XRD. This study investigated the catalytic properties of modified composite molecular sieves with Ni and Mo at different loaded ratios on the pyrolysis of hydrolyzed lignin. Results indicated that HM loaded with different metals had different catalytic pyrolysis selectivity. The relative yield of MAHs on 3 %Ni-HM was the highest, at 27.78 %, while that of phenolic on 5 %Mo-HM was 51.02 %. Thus, by modifying the co-loading ratios between Ni and Mo, the combined catalytic pyrolysis of hydrolyzed lignin was performed, achieving a 39.24 % yield of MAHs on the catalyst Mo<sub>1</sub>Ni<sub>2</sub>-HM, markedly surpassing the 17.69 % yield from unaltered HZSM-5/MCM-41. In addition, the improvement of active sites was caused by transition metals loaded and the synergistic effect between bimetals enhanced the catalytic activity and stability. HZSM-5/MCM-41 loaded with metal oxides promoted the depolymerization of macromolecules in the intermediate products of pyrolysis, and thus improved the relative yield of MAHs among pyrolysis products of hydrolyzed lignin.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106819"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433678","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106811
Daria Robertson, Paula Nousiainen, Leena Pitkänen, Inge Schlapp-Hackl, Dmitrii Rusakov, Michael Hummel
Numerous studies have explored the behaviour of various lignin types during carbonisation. Yet, misconceptions persist regarding the effects arising from both the source plant and production method of lignin. Lignin is often referenced merely by type, lacking detailed characterisation. Our research examines the properties of three lignin types, elucidates their behaviour during pyrolysis, and establishes the structure-property correlation and interaction of lignin with deep eutectic solvents. By combining several analytical techniques — including NMR, FTIR, XPS, TGA-MS for functional group detection, and HPLC, EA, and ICP for compositional analysis, alongside particle size distribution and SEC for morphology — we can conduct a thorough analysis that facilitates a meaningful comparison across lignin types. This approach allows for better control over the desired carbon properties. Furthermore, we demonstrate how modification with deep eutectic solvents enables the production of biochar from different lignin types, exhibiting properties conducive to large-scale, one-step sustainable production of biochar.
{"title":"Carbonisation of lignin in the presence of a eutectic salt mixture: Identifying the lignin properties that govern the characteristics of the resulting carbon material","authors":"Daria Robertson, Paula Nousiainen, Leena Pitkänen, Inge Schlapp-Hackl, Dmitrii Rusakov, Michael Hummel","doi":"10.1016/j.jaap.2024.106811","DOIUrl":"10.1016/j.jaap.2024.106811","url":null,"abstract":"<div><div>Numerous studies have explored the behaviour of various lignin types during carbonisation. Yet, misconceptions persist regarding the effects arising from both the source plant and production method of lignin. Lignin is often referenced merely by type, lacking detailed characterisation. Our research examines the properties of three lignin types, elucidates their behaviour during pyrolysis, and establishes the structure-property correlation and interaction of lignin with deep eutectic solvents. By combining several analytical techniques — including NMR, FTIR, XPS, TGA-MS for functional group detection, and HPLC, EA, and ICP for compositional analysis, alongside particle size distribution and SEC for morphology — we can conduct a thorough analysis that facilitates a meaningful comparison across lignin types. This approach allows for better control over the desired carbon properties. Furthermore, we demonstrate how modification with deep eutectic solvents enables the production of biochar from different lignin types, exhibiting properties conducive to large-scale, one-step sustainable production of biochar.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106811"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-01DOI: 10.1016/j.jaap.2024.106824
Wenxuan Wu , Felix Wiesner , Juan P. Hidalgo , Jeffrey J. Morrell , Luis Yermán
Chromated copper arsenate (CCA) is a preservative treatment that enhances the biodegradation resistance of wood, essential for prolonging the service life of exterior infrastructure. However, the susceptibility of CCA-treated wood to smouldering combustion presents a significant challenge, as the metals present in the CCA catalyze the smouldering. In this work, we examined the oxidative behaviour of char produced from CCA-treated wood through dynamic thermogravimetric analysis. There was a gradual decrease in the catalytic activity of the CCA as temperature increased, particularly above 400 °C. At this stage, lignin undergoes secondary pyrolysis, and thermal decomposition of CCA complexes occurs. The thermal decomposition of CCA-treated wood at temperatures above 650 °C was similar to that of untreated wood, indicating the possible deactivation of the CCA. The agglomeration of species containing Cu or Cr above 650 °C might be responsible for the deactivation. This process is influenced by simultaneous lignin pyrolysis and decomposition of CCA complexes, which are also likely contributors to the loss of CCA's catalytic activity. This research introduced a novel experimental approach to assess the catalytic effects of CCA on char oxidation at elevated temperatures, offering valuable insights into CCA deactivation and its implications for fire safety. It also contributes to the development of potential modifications to CCA formulations aimed to reduce smouldering in wildfire-prone regions.
铬化砷酸铜（CCA）是一种防腐处理剂，可增强木材的抗生物降解能力，对延长外部基础设施的使用寿命至关重要。然而，由于铬化砷酸铜中的金属会催化烟熏燃烧，因此铬化砷酸铜处理过的木材易受烟熏燃烧的影响，这给我们带来了巨大的挑战。在这项工作中，我们通过动态热重分析研究了经铬化砷酸铜处理的木材产生的炭的氧化行为。随着温度的升高，CCA 的催化活性逐渐降低，尤其是在 400 °C 以上。在此阶段，木质素发生二次热解，CCA 复合物发生热分解。CCA 处理过的木材在 650 °C 以上的热分解与未处理过的木材相似，表明 CCA 可能失活。温度高于 650 °C 时，含铜或铬的物种聚集可能是导致失活的原因。这一过程同时受到木质素热解和 CCA 复合物分解的影响，这也可能是导致 CCA 失去催化活性的原因。这项研究采用了一种新颖的实验方法来评估 CCA 在高温下对木炭氧化的催化作用，为深入了解 CCA 失活及其对消防安全的影响提供了宝贵的资料。它还有助于开发对 CCA 配方的潜在改良，以减少野火易发地区的烟熏现象。
{"title":"Deactivation of chromated copper arsenate as a catalyst in smouldering of wood","authors":"Wenxuan Wu , Felix Wiesner , Juan P. Hidalgo , Jeffrey J. Morrell , Luis Yermán","doi":"10.1016/j.jaap.2024.106824","DOIUrl":"10.1016/j.jaap.2024.106824","url":null,"abstract":"<div><div>Chromated copper arsenate (CCA) is a preservative treatment that enhances the biodegradation resistance of wood, essential for prolonging the service life of exterior infrastructure. However, the susceptibility of CCA-treated wood to smouldering combustion presents a significant challenge, as the metals present in the CCA catalyze the smouldering. In this work, we examined the oxidative behaviour of char produced from CCA-treated wood through dynamic thermogravimetric analysis. There was a gradual decrease in the catalytic activity of the CCA as temperature increased, particularly above 400 °C. At this stage, lignin undergoes secondary pyrolysis, and thermal decomposition of CCA complexes occurs. The thermal decomposition of CCA-treated wood at temperatures above 650 °C was similar to that of untreated wood, indicating the possible deactivation of the CCA. The agglomeration of species containing Cu or Cr above 650 °C might be responsible for the deactivation. This process is influenced by simultaneous lignin pyrolysis and decomposition of CCA complexes, which are also likely contributors to the loss of CCA's catalytic activity. This research introduced a novel experimental approach to assess the catalytic effects of CCA on char oxidation at elevated temperatures, offering valuable insights into CCA deactivation and its implications for fire safety. It also contributes to the development of potential modifications to CCA formulations aimed to reduce smouldering in wildfire-prone regions.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"183 ","pages":"Article 106824"},"PeriodicalIF":5.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142535667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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