Using a segment heating method, Cinnamomum camphora leaf essential oil yield was improved by a microwave-assisted heating device, with silicon carbide serving as microwave-absorbing heat medium. The effects of temperature segment heating on the essential oil yield were investigated. The mechanism by which microwave-assisted segmented heating enhances essential oil yield in the pyrolysis oil was explored by analyzing the composition of gas and liquid products, as well as the morphology of solid residues after pyrolysis. The results showed that the essential oil using a four-segment heating method (Room temperature–250 °C, 250–300 °C, 300–350 °C, and 350–450 °C) produced the highest yield, reaching 4.40 ± 0.39 %, primarily due to the strategy of keeping the pyrolysis temperature at the boiling point of the essential oil for a period of time. Additionally, leaf cells undergo dual heating from microwave radiation and heat conduction by SiC promoted the rupture of cell walls and vacuoles. Kinetic models were obtained, which have strong consistency between predicted and experimental results, and theoretical maximum yield was significantly higher than that of previously reported. This method will play a crucial role in guiding improvements in plant essential oil yield and is expected to generate substantial economic benefits.
{"title":"Improvement of essential oil yield in the pyrolysis oil of Cinnamomum camphora leaves using a microwave-assisted segment heating method: Product analysis, mechanism and kinetic model","authors":"Ying Duan, Jiangshun Deng, Liyuan Wang, Zhaoqing Yang, Haimei Zhao, Qinglong Xie, Yong Nie","doi":"10.1016/j.jaap.2025.107065","DOIUrl":"10.1016/j.jaap.2025.107065","url":null,"abstract":"<div><div>Using a segment heating method, <em>Cinnamomum camphora</em> leaf essential oil yield was improved by a microwave-assisted heating device, with silicon carbide serving as microwave-absorbing heat medium. The effects of temperature segment heating on the essential oil yield were investigated. The mechanism by which microwave-assisted segmented heating enhances essential oil yield in the pyrolysis oil was explored by analyzing the composition of gas and liquid products, as well as the morphology of solid residues after pyrolysis. The results showed that the essential oil using a four-segment heating method (Room temperature–250 °C, 250–300 °C, 300–350 °C, and 350–450 °C) produced the highest yield, reaching 4.40 ± 0.39 %, primarily due to the strategy of keeping the pyrolysis temperature at the boiling point of the essential oil for a period of time. Additionally, leaf cells undergo dual heating from microwave radiation and heat conduction by SiC promoted the rupture of cell walls and vacuoles. Kinetic models were obtained, which have strong consistency between predicted and experimental results, and theoretical maximum yield was significantly higher than that of previously reported. This method will play a crucial role in guiding improvements in plant essential oil yield and is expected to generate substantial economic benefits.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"189 ","pages":"Article 107065"},"PeriodicalIF":5.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143534430","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 : 2025-02-27DOI: 10.1016/j.jaap.2025.107063
Huanpei Xia , Lei Xu , Yongfen Sun , Cheng Xie , Changhao Zuo , Di Zhang , Guangsheng Yao , Meng Liu , Feng Wang , Junyu Lu
Hematite is one of the major wastes in rare earth production and its utilization requires reduction. However, the traditional carbothermic reduction requires a large amount of fossil energy, and the process of coking and reduction results in a significant waste of thermal energy. Therefore, there is an urgent need to develop new green carbothermic reduction technologies. In this study, the strategy of whole-component utilization of biomass pyrolysis products was employed to carry out microwave thermal reduction of hematite using biochar and pyrolysis gas derived from integrated fruit peel waste. Biochar shows excellent microwave-thermal conversion ability: it can participate in microwave carbothermic reduction reaction as both heating medium and reduction medium in the reduction process. Under the synergistic effect of biochar and pyrolysis gas, the reduction temperature of hematite was lowered, the metallization rate of the reduction products was enhanced, and the whole-component utilization of biomass pyrolysis products was realized. The biochar-gas coupling process has been demonstrated to facilitate the metallization of hematite to a significant extent. A 93.32 % hematite metallization rate was achieved within 30 min of microwave reduction at 1000°C, with only 15.62 % biochar consumption. The results show the dual contributions of biochar and pyrolysis gas under microwaves, providing a new approach to biomass waste and tailings utilization.
{"title":"Clean microwave carbothermic reduction of hematite using biomass-derived products: Dual role of biochar and pyrolysis gas","authors":"Huanpei Xia , Lei Xu , Yongfen Sun , Cheng Xie , Changhao Zuo , Di Zhang , Guangsheng Yao , Meng Liu , Feng Wang , Junyu Lu","doi":"10.1016/j.jaap.2025.107063","DOIUrl":"10.1016/j.jaap.2025.107063","url":null,"abstract":"<div><div>Hematite is one of the major wastes in rare earth production and its utilization requires reduction. However, the traditional carbothermic reduction requires a large amount of fossil energy, and the process of coking and reduction results in a significant waste of thermal energy. Therefore, there is an urgent need to develop new green carbothermic reduction technologies. In this study, the strategy of whole-component utilization of biomass pyrolysis products was employed to carry out microwave thermal reduction of hematite using biochar and pyrolysis gas derived from integrated fruit peel waste. Biochar shows excellent microwave-thermal conversion ability: it can participate in microwave carbothermic reduction reaction as both heating medium and reduction medium in the reduction process. Under the synergistic effect of biochar and pyrolysis gas, the reduction temperature of hematite was lowered, the metallization rate of the reduction products was enhanced, and the whole-component utilization of biomass pyrolysis products was realized. The biochar-gas coupling process has been demonstrated to facilitate the metallization of hematite to a significant extent. A 93.32 % hematite metallization rate was achieved within 30 min of microwave reduction at 1000°C, with only 15.62 % biochar consumption. The results show the dual contributions of biochar and pyrolysis gas under microwaves, providing a new approach to biomass waste and tailings utilization.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"189 ","pages":"Article 107063"},"PeriodicalIF":5.8,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143529603","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 : 2025-02-26DOI: 10.1016/j.jaap.2025.107056
Hiroaki Sato , Sayaka Nakamura , Hideyuki Shinzawa
Pyrolysis-gas chromatography is utilized as an effective method for the characterization of polymers. The notorious complexity of the resultant pyrograms, however, makes it difficult to overview and compare the numerous pyrogram differences. Inspired by Kendrick mass defect plots used in high-resolution mass spectrometry, we propose here a new form of graphical representation of the chemical structure of polymers that visualizes the distribution of a set of pyrolysates on a two-dimensional plot that is based on the retention index (RI). When the elution time of a chromatographic peak is expressed relative to the carbon number of the n-alkane, the integer part should reflect the carbon number, and the decimal part should reflect the structural difference from the saturated version of the same hydrocarbon. We proceeded by dividing the RI/100 values into integer and decimal parts and created a two-dimensional plot, which we call an RI defect (RID) plot. To explain the features and effectiveness of this method, we present here several examples of its application to the characterization of polyolefins. The RID plot is first demonstrated by applying it to the identification of polyethylenes (PEs) with different short-chain branching patterns and polypropylenes (PPs) with different stereoregularities. This technique was further applied to the characterization of recycled PP resins, by which we were able to visualize the compositional distribution of minor PE components of major PP. Furthermore, a differential reading technique combined with the RID plot allowed for a rough classification of recycled PP based on the composition of the PE components.
{"title":"Two-dimensional plot of Py-GC based on retention index to depict the compositional distribution of pyrolysates of olefin polymers","authors":"Hiroaki Sato , Sayaka Nakamura , Hideyuki Shinzawa","doi":"10.1016/j.jaap.2025.107056","DOIUrl":"10.1016/j.jaap.2025.107056","url":null,"abstract":"<div><div>Pyrolysis-gas chromatography is utilized as an effective method for the characterization of polymers. The notorious complexity of the resultant pyrograms, however, makes it difficult to overview and compare the numerous pyrogram differences. Inspired by Kendrick mass defect plots used in high-resolution mass spectrometry, we propose here a new form of graphical representation of the chemical structure of polymers that visualizes the distribution of a set of pyrolysates on a two-dimensional plot that is based on the retention index (RI). When the elution time of a chromatographic peak is expressed relative to the carbon number of the n-alkane, the integer part should reflect the carbon number, and the decimal part should reflect the structural difference from the saturated version of the same hydrocarbon. We proceeded by dividing the RI/100 values into integer and decimal parts and created a two-dimensional plot, which we call an RI defect (RID) plot. To explain the features and effectiveness of this method, we present here several examples of its application to the characterization of polyolefins. The RID plot is first demonstrated by applying it to the identification of polyethylenes (PEs) with different short-chain branching patterns and polypropylenes (PPs) with different stereoregularities. This technique was further applied to the characterization of recycled PP resins, by which we were able to visualize the compositional distribution of minor PE components of major PP. Furthermore, a differential reading technique combined with the RID plot allowed for a rough classification of recycled PP based on the composition of the PE components.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"189 ","pages":"Article 107056"},"PeriodicalIF":5.8,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143520982","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 : 2025-02-25DOI: 10.1016/j.jaap.2025.107062
Francesca Cerciello, Carmela Russo, Osvalda Senneca, Renata Migliaccio, Maria Maddalena Oliano, Barbara Apicella
Thermal decomposition of a reconstituted cast-leaf tobacco used in heated tobacco products (HTP) was investigated at heating rates of 5–100 °C/min both in inert and oxidative atmospheres, up to 550 °C. Experiments were carried out in a thermogravimetric apparatus, to obtain a global apparent kinetic model, and in a fixed-bed reactor, for sampling of the emitted decomposition products at a wide range of heating rates. An array of diagnostics was used to analyze liquid and gaseous products.
Under the experimental conditions tested, oxygen did not induce combustion of fixed carbon until 400 °C, but did affect the rate of formation and chemical composition of condensable and gaseous products. The most remarkable effect of oxygen was to favour the formation of small hydrocarbons, such as methane and unsaturated species, particularly acetylene. Above 400 °C acetylene was shown to decrease when enhancing the growth of polycyclic aromatic hydrocarbons (PAHs) with up to six aromatic rings.
The kinetic model obtained from fitting of thermogravimetric curves accounted for the existence within the sample of six components, which could be traced back to the main components and ingredients of reconstituted cast-leaf tobacco. Even though the model provided only a global simplified description of thermal degradation in terms of mass loss, neglecting both the interactions among solid components and the complex cracking and recombination reactions within the volatiles, it served as basis for the discussion of the results of the reactor experiments and to extend them further to heating rates relevant for HTP operating conditions.
Results indicate that for temperature conditions relevant for HTPs, glycerol release and hemicellulose decomposition can occur in parallel and could in principle favour acetylene formation, even if it has not been reported in HTP aerosols in the literature. Nevertheless, the temperature in HTPs is typically kept below 350 °C, which ensures that combustion of the tobacco does not occur, limits the onset of lignin thermal degradation, and prevents the formation and growth of PAHs and subsequent formation of soot from happening.
{"title":"Volatile species and polycyclic aromatic hydrocarbons upon thermal (oxidative) decomposition of lignocellulosic biomass: The insightful case of reconstituted cast-leaf tobacco","authors":"Francesca Cerciello, Carmela Russo, Osvalda Senneca, Renata Migliaccio, Maria Maddalena Oliano, Barbara Apicella","doi":"10.1016/j.jaap.2025.107062","DOIUrl":"10.1016/j.jaap.2025.107062","url":null,"abstract":"<div><div>Thermal decomposition of a reconstituted cast-leaf tobacco used in heated tobacco products (HTP) was investigated at heating rates of 5–100 °C/min both in inert and oxidative atmospheres, up to 550 °C. Experiments were carried out in a thermogravimetric apparatus, to obtain a global apparent kinetic model, and in a fixed-bed reactor, for sampling of the emitted decomposition products at a wide range of heating rates. An array of diagnostics was used to analyze liquid and gaseous products.</div><div>Under the experimental conditions tested, oxygen did not induce combustion of fixed carbon until 400 °C, but did affect the rate of formation and chemical composition of condensable and gaseous products. The most remarkable effect of oxygen was to favour the formation of small hydrocarbons, such as methane and unsaturated species, particularly acetylene. Above 400 °C acetylene was shown to decrease when enhancing the growth of polycyclic aromatic hydrocarbons (PAHs) with up to six aromatic rings.</div><div>The kinetic model obtained from fitting of thermogravimetric curves accounted for the existence within the sample of six components, which could be traced back to the main components and ingredients of reconstituted cast-leaf tobacco. Even though the model provided only a global simplified description of thermal degradation in terms of mass loss, neglecting both the interactions among solid components and the complex cracking and recombination reactions within the volatiles, it served as basis for the discussion of the results of the reactor experiments and to extend them further to heating rates relevant for HTP operating conditions.</div><div>Results indicate that for temperature conditions relevant for HTPs, glycerol release and hemicellulose decomposition can occur in parallel and could in principle favour acetylene formation, even if it has not been reported in HTP aerosols in the literature. Nevertheless, the temperature in HTPs is typically kept below 350 °C, which ensures that combustion of the tobacco does not occur, limits the onset of lignin thermal degradation, and prevents the formation and growth of PAHs and subsequent formation of soot from happening.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"189 ","pages":"Article 107062"},"PeriodicalIF":5.8,"publicationDate":"2025-02-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512272","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 : 2025-02-24DOI: 10.1016/j.jaap.2025.107059
Fu Wei , Jing-Pei Cao , Jing-Ping Zhao , Xiao-Yan Zhao
Biomass, a renewable resource, presents inherent challenges for selective conversion into high-value chemicals based on the compositional structure of biomass via conventional pyrolysis. This study introduced an innovative two-stage pyrolysis, combining acid-catalyzed low-temperature pyrolysis with catalytic upgrading over ZSM-5, for the targeted valorization of H3PO4-loaded corncobs. This approach notably outperformed conventional non-catalytic/catalytic and two-stage non-catalytic pyrolysis, achieving higher yields of levoglucosenone, furfural, and cumulative target products. Mechanistic analyses revealed that H3PO4 loading enhanced selective conversion of cellulose and hemicellulose to levoglucosenone and furfural at reduced temperatures by passivating metals and enhancing dehydration reactions. Notably, the maximum furfural yield remained stable across a broad range of acid loadings, ensuring that fluctuations in the actual H3PO4 loading did not significantly impact maximum levoglucosenone yield within practical limits. Furthermore, lignin-rich char residue was effectively converted to light aromatics in the catalytic upgrading stage with high selectivity, albeit at a lower overall yield. Optimal conditions were achieved with 5.5 wt% H3PO4 at 325 °C for the first stage, followed by catalytic upgrading at 550 °C, producing a maximum total yield of 62.6 mg/g of target products. Peak yields of levoglucosenone and furfural reached 23.5 and 34.5 mg/g, respectively, while light aromatics reached 4.6 mg/g with over 98 % selectivity. This study underscores the potential of coupling acid-catalyzed pyrolysis with catalytic upgrading to achieve targeted co-production of valuable chemicals, providing new insights into biomass valorization.
{"title":"Unlocking biofuel potential: Synergistic production of biofuel precursors from acid-loaded corncobs via staged pyrolysis","authors":"Fu Wei , Jing-Pei Cao , Jing-Ping Zhao , Xiao-Yan Zhao","doi":"10.1016/j.jaap.2025.107059","DOIUrl":"10.1016/j.jaap.2025.107059","url":null,"abstract":"<div><div>Biomass, a renewable resource, presents inherent challenges for selective conversion into high-value chemicals based on the compositional structure of biomass via conventional pyrolysis. This study introduced an innovative two-stage pyrolysis, combining acid-catalyzed low-temperature pyrolysis with catalytic upgrading over ZSM-5, for the targeted valorization of H<sub>3</sub>PO<sub>4</sub>-loaded corncobs. This approach notably outperformed conventional non-catalytic/catalytic and two-stage non-catalytic pyrolysis, achieving higher yields of levoglucosenone, furfural, and cumulative target products. Mechanistic analyses revealed that H<sub>3</sub>PO<sub>4</sub> loading enhanced selective conversion of cellulose and hemicellulose to levoglucosenone and furfural at reduced temperatures by passivating metals and enhancing dehydration reactions. Notably, the maximum furfural yield remained stable across a broad range of acid loadings, ensuring that fluctuations in the actual H<sub>3</sub>PO<sub>4</sub> loading did not significantly impact maximum levoglucosenone yield within practical limits. Furthermore, lignin-rich char residue was effectively converted to light aromatics in the catalytic upgrading stage with high selectivity, albeit at a lower overall yield. Optimal conditions were achieved with 5.5 wt% H<sub>3</sub>PO<sub>4</sub> at 325 °C for the first stage, followed by catalytic upgrading at 550 °C, producing a maximum total yield of 62.6 mg/g of target products. Peak yields of levoglucosenone and furfural reached 23.5 and 34.5 mg/g, respectively, while light aromatics reached 4.6 mg/g with over 98 % selectivity. This study underscores the potential of coupling acid-catalyzed pyrolysis with catalytic upgrading to achieve targeted co-production of valuable chemicals, providing new insights into biomass valorization.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"188 ","pages":"Article 107059"},"PeriodicalIF":5.8,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487637","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 : 2025-02-24DOI: 10.1016/j.jaap.2025.107061
Oybek Mirzayev, Firdavs Aliev , Sergei Sitnov, Temurali Kholmurodov, Rezeda Mukhamatdinova, Mustafa Ismael, Sofya Trubitsina, Abdulvahhab Mohammed Al-Qaz, Alexey Vakhin
The CO2-assisted aqueous pyrolysis of heavy oil in the reservoir formations is one of the most promising methods to enhance heavy oil recovery and utilize carbon dioxide into value-added products. The study examines the performance of the oil-soluble catalysts and dispersed sodium nanoparticles on the upgrading degree of heavy oil and carbon dioxide hydrogenation degree. Various analytical tools such as SARA analysis, viscosity measurements, elemental analysis, gas chromatography, spectroscopy-based analysis methods (EPR, GC-MS and FT-IR analysis) were employed to evaluate the upgrading efficiency of the synthesized catalysts. The relative content of the evolved CO2 in the presence of Fe-Na nanoparticles was reduced from 78 % (blank) to 31 %, while the sum of C1-C5 n-alkanes was increased from 9.2 % to 41.6 %. The Ni-Na nanoparticles exhibited high activity on destructive hydrogenation of resins and asphaltenes such that reduced the mass ratio of heavy fragments by 35 % and increased the mass content of light fractions by 21 %. The CO2-assisted aqueous pyrolysis of heavy oil in the presence of sodium-promoted transition metal oxides and sulfides contributed to the viscosity reduction by 89 %. Taken together, we have found a cutting-edge solution for carbon dioxide utilization and obtained comprehensive experimental results for upgrading of heavy oil in-situ.
{"title":"Carbon dioxide-assisted aqueous pyrolysis of heavy oil in the presence of oil-soluble catalysts and sodium nanoparticles","authors":"Oybek Mirzayev, Firdavs Aliev , Sergei Sitnov, Temurali Kholmurodov, Rezeda Mukhamatdinova, Mustafa Ismael, Sofya Trubitsina, Abdulvahhab Mohammed Al-Qaz, Alexey Vakhin","doi":"10.1016/j.jaap.2025.107061","DOIUrl":"10.1016/j.jaap.2025.107061","url":null,"abstract":"<div><div>The CO<sub>2</sub>-assisted aqueous pyrolysis of heavy oil in the reservoir formations is one of the most promising methods to enhance heavy oil recovery and utilize carbon dioxide into value-added products. The study examines the performance of the oil-soluble catalysts and dispersed sodium nanoparticles on the upgrading degree of heavy oil and carbon dioxide hydrogenation degree. Various analytical tools such as SARA analysis, viscosity measurements, elemental analysis, gas chromatography, spectroscopy-based analysis methods (EPR, GC-MS and FT-IR analysis) were employed to evaluate the upgrading efficiency of the synthesized catalysts. The relative content of the evolved CO<sub>2</sub> in the presence of Fe-Na nanoparticles was reduced from 78 % (blank) to 31 %, while the sum of C1-C5 n-alkanes was increased from 9.2 % to 41.6 %. The Ni-Na nanoparticles exhibited high activity on destructive hydrogenation of resins and asphaltenes such that reduced the mass ratio of heavy fragments by 35 % and increased the mass content of light fractions by 21 %. The CO<sub>2</sub>-assisted aqueous pyrolysis of heavy oil in the presence of sodium-promoted transition metal oxides and sulfides contributed to the viscosity reduction by 89 %. Taken together, we have found a cutting-edge solution for carbon dioxide utilization and obtained comprehensive experimental results for upgrading of heavy oil in-situ.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"189 ","pages":"Article 107061"},"PeriodicalIF":5.8,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512271","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}
To explore the coal types appropriate for direct reduction in rotary kiln, this paper focuses on three distinct coal types—lignite, bituminous coal, and anthracite—as the subjects of our experiments. The aim is to comprehend their pyrolysis properties and evaluate their suitability for direct reduction in rotary kiln. First, the requirement of coal quality in direct reduction process of rotary kiln was analyzed. Pyrolysis experiments and thermogravimetry–mass spectrometry (TG–MS) analyses of different coal types were carried out. Brunauer–Emmett–Teller (BET) method and thermogravimetry–differential scanning calorimetry (TG–DSC) were employed to analyze pore structure characteristics reactivity of the coals at different ranks. Furthermore, In order to further characterize properties of coals at different ranks，X-ray diffraction (XRD) was employed to analyze the molecular configuration of the raw coal and resulting coke samples after pyrolysis. Finally, a comprehensive evaluation system for coal was established by comparing the pyrolysis products, pore structural parameters, and gasification reactivity of coals at different ranks. The results indicate that the proportions of pyrolysis gas from lignite and bituminous coal are relatively high. The char of lignite has the largest BET surface area and total pore volume. In the gasification stage, the maximum weight loss rate of lignite reaches 5.89(%·min−1) for the first time at 894℃.The crystallite structure parameters confirm the accuracy of pore parameters and gasification reaction results from the microscopic perspective. Comprehensive analysis shows thatlignite have the highest pyrolysis gas content was, the largest BET specific surface area and total pore volume, and the lowest peak temperature of gasification rate, which is undoubtedly more suitable for the direct iron reduction process in rotary kiln.
{"title":"Comprehensive evaluation and analysis of coal used for direct reduction in rotary kiln","authors":"Weiyang Zhang , Hanjie Guo , Shusen Cheng , Xiaodong Ren , Jing Guo","doi":"10.1016/j.jaap.2025.107060","DOIUrl":"10.1016/j.jaap.2025.107060","url":null,"abstract":"<div><div>To explore the coal types appropriate for direct reduction in rotary kiln, this paper focuses on three distinct coal types—lignite, bituminous coal, and anthracite—as the subjects of our experiments. The aim is to comprehend their pyrolysis properties and evaluate their suitability for direct reduction in rotary kiln. First, the requirement of coal quality in direct reduction process of rotary kiln was analyzed. Pyrolysis experiments and thermogravimetry–mass spectrometry (TG–MS) analyses of different coal types were carried out. Brunauer–Emmett–Teller (BET) method and thermogravimetry–differential scanning calorimetry (TG–DSC) were employed to analyze pore structure characteristics reactivity of the coals at different ranks. Furthermore, In order to further characterize properties of coals at different ranks，X-ray diffraction (XRD) was employed to analyze the molecular configuration of the raw coal and resulting coke samples after pyrolysis. Finally, a comprehensive evaluation system for coal was established by comparing the pyrolysis products, pore structural parameters, and gasification reactivity of coals at different ranks. The results indicate that the proportions of pyrolysis gas from lignite and bituminous coal are relatively high. The char of lignite has the largest BET surface area and total pore volume. In the gasification stage, the maximum weight loss rate of lignite reaches 5.89(%·min<sup>−1</sup>) for the first time at 894℃.The crystallite structure parameters confirm the accuracy of pore parameters and gasification reaction results from the microscopic perspective. Comprehensive analysis shows thatlignite have the highest pyrolysis gas content was, the largest BET specific surface area and total pore volume, and the lowest peak temperature of gasification rate, which is undoubtedly more suitable for the direct iron reduction process in rotary kiln.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"188 ","pages":"Article 107060"},"PeriodicalIF":5.8,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487639","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 : 2025-02-24DOI: 10.1016/j.jaap.2025.107058
Irek I. Mukhamatdinov , Saleem M.A. Saif , Mohammed O.N. Ali , Rezeda E. Mukhamatdinova , Boudkhil Affane , Alexey V. Vakhin , Sergey V. Tsvetkov , Alexander N. Protsenko , Dmitry A. Volkov
This study explored the catalytic upgrading of high-viscosity oil from the Aksenovsk field in the Samara region during catalytic aquathermolysis on the composition and properties of the resulting products. Catalysts containing iron, nickel, cobalt, chromium, and copper were successfully synthesized. The results revealed significant oil transformation with copper tallate, leading to a 2.6-fold reduction in viscosity compared to the control. SARA analysis showed an 8 % mass decrease in high-molecular-weight compounds, especially resins, when using an iron-nickel (1:1) catalyst mixture. Iron tallate in the conversion products resulted in a 17 % increase in light saturates. X-ray structural analysis revealed that nickel, cobalt, and copper tallates primarily decompose into metal sulfides, while iron and chromium tallates break down into oxides and hydroxides. Based on these findings, a catalyst precursor with an 85/15 iron-nickel ratio was selected, and field tests at well 407 G in the Aksenovsk field demonstrated increased production rates and reduced water content.
{"title":"Development of a catalyst based on metal tallates for intensification of heavy oil production","authors":"Irek I. Mukhamatdinov , Saleem M.A. Saif , Mohammed O.N. Ali , Rezeda E. Mukhamatdinova , Boudkhil Affane , Alexey V. Vakhin , Sergey V. Tsvetkov , Alexander N. Protsenko , Dmitry A. Volkov","doi":"10.1016/j.jaap.2025.107058","DOIUrl":"10.1016/j.jaap.2025.107058","url":null,"abstract":"<div><div>This study explored the catalytic upgrading of high-viscosity oil from the Aksenovsk field in the Samara region during catalytic aquathermolysis on the composition and properties of the resulting products. Catalysts containing iron, nickel, cobalt, chromium, and copper were successfully synthesized. The results revealed significant oil transformation with copper tallate, leading to a 2.6-fold reduction in viscosity compared to the control. SARA analysis showed an 8 % mass decrease in high-molecular-weight compounds, especially resins, when using an iron-nickel (1:1) catalyst mixture. Iron tallate in the conversion products resulted in a 17 % increase in light saturates. X-ray structural analysis revealed that nickel, cobalt, and copper tallates primarily decompose into metal sulfides, while iron and chromium tallates break down into oxides and hydroxides. Based on these findings, a catalyst precursor with an 85/15 iron-nickel ratio was selected, and field tests at well 407 G in the Aksenovsk field demonstrated increased production rates and reduced water content.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"189 ","pages":"Article 107058"},"PeriodicalIF":5.8,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143512270","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 : 2025-02-22DOI: 10.1016/j.jaap.2025.107046
Bing Wang , Ying-Bo Song , Feng Wang , Yun-Chang Fan , Nuo Cheng , Pei-Gao Duan
Pyrolysis offers significant advantages for the resourceful recycling of waste tyre (WT), while molecular distillation can efficiently separate and non-destructively collect the resulting pyrolysis oil for high-value utilisation of different oil fractions. Herein, WT was pyrolysed at various temperatures (350 °C, 400 °C, 450 °C and 500 °C) to obtain the desired pyrolysis products. The optimal pyrolysis temperature of 400 °C was selected based on the analysis of WT pyrolysis at temperatures ranging from 350 °C to 500 °C. Subsequently, molecular distillation experiments were conducted on the waste tyre pyrolysis oil (WTPO) obtained at 400 °C. The distillation process was carried out at varying temperatures (100 °C, 115 °C, 130 °C, 145 °C and 160 °C) to separate the WTPO into light oil (LO) and heavy oil (HO), including LO130 °C (LO obtained at 130 °C) and HO130 °C (HO obtained at 130 °C). The characteristics of the pyrolysis products and WTPO fractions were investigated, with a focus on the effect of temperature on the yield and composition distribution of the pyrolysis products as well as the distribution pattern of WTPO fractions. The maximum pyrolysis oil output was obtained at 400 °C (58.23 wt%), with a high proportion of alkane (9.42 %) and aromatics (75.07 %). LO130 °C contained more olefins (16.55 %) and ketones (7.37 %) than HO130 °C, whereas HO130 °C had more alkanes (5.65 %) and aromatic hydrocarbons (61.99 %). The findings of this study suggest the effectiveness of using molecular distillation to separate WTPO fractions.
{"title":"Comparative study on properties of waste tyre pyrolysis oil and its distillates obtained by molecular distillation","authors":"Bing Wang , Ying-Bo Song , Feng Wang , Yun-Chang Fan , Nuo Cheng , Pei-Gao Duan","doi":"10.1016/j.jaap.2025.107046","DOIUrl":"10.1016/j.jaap.2025.107046","url":null,"abstract":"<div><div>Pyrolysis offers significant advantages for the resourceful recycling of waste tyre (WT), while molecular distillation can efficiently separate and non-destructively collect the resulting pyrolysis oil for high-value utilisation of different oil fractions. Herein, WT was pyrolysed at various temperatures (350 °C, 400 °C, 450 °C and 500 °C) to obtain the desired pyrolysis products. The optimal pyrolysis temperature of 400 °C was selected based on the analysis of WT pyrolysis at temperatures ranging from 350 °C to 500 °C. Subsequently, molecular distillation experiments were conducted on the waste tyre pyrolysis oil (WTPO) obtained at 400 °C. The distillation process was carried out at varying temperatures (100 °C, 115 °C, 130 °C, 145 °C and 160 °C) to separate the WTPO into light oil (LO) and heavy oil (HO), including LO<sub>130 °C</sub> (LO obtained at 130 °C) and HO<sub>130 °C</sub> (HO obtained at 130 °C). The characteristics of the pyrolysis products and WTPO fractions were investigated, with a focus on the effect of temperature on the yield and composition distribution of the pyrolysis products as well as the distribution pattern of WTPO fractions. The maximum pyrolysis oil output was obtained at 400 °C (58.23 wt%), with a high proportion of alkane (9.42 %) and aromatics (75.07 %). LO<sub>130 °C</sub> contained more olefins (16.55 %) and ketones (7.37 %) than HO<sub>130 °C</sub>, whereas HO<sub>130 °C</sub> had more alkanes (5.65 %) and aromatic hydrocarbons (61.99 %). The findings of this study suggest the effectiveness of using molecular distillation to separate WTPO fractions.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"188 ","pages":"Article 107046"},"PeriodicalIF":5.8,"publicationDate":"2025-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487640","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 : 2025-02-21DOI: 10.1016/j.jaap.2025.107048
Michael Zeller, Daniela Merz, Luca Weigel, Salar Tavakkol, Dieter Stapf
Polyurethanes (PUR) are versatile polymers used in a broad range of applications. Conventional mechanical recycling is thus difficult. Chemical recycling such as pyrolytic waste treatment presents new recycling options. Advanced recycling by pyrolysis may help to reduce environmental impacts from PUR wastes. The knowledge of mechanisms, products and yields is essential for the design of efficient pyrolysis processes. Rigid (RPUF) and flexible foams (FPUF), a cast elastomer (CE) and a thermoplastic Polyurethane (TPU) have been investigated by thermogravimetry (TG) and FTIR-spectroscopy. Two decomposition steps have been identified. CO2 is mainly released in the first decomposition step between 250 °C and 400 °C. The second decomposition step at temperatures above 400 °C releases polyol fragments and marginal amounts of CO2. Strong feedstock dependency is evident. Quantitative tracing for the CO2 release was developed, validated and applied. This allows the resolution of specific decomposition phenomena, mass balancing and distinguishing potentially valuable volatiles from CO2 and solid residues. CO2 yields are 12.0 mass-% for RPUF, 4.0 mass-% for FPUF, 3.2 mass-% for CE and 5.3 mass-% for TPU. Considering solids and CO2 as losses, recycling potentials were determined which are 74 mass-% for RPUF, 90 mass-% for FPUF, 95 mass% for CE and 93 mass-% for TPU. This facilitates further process development based on polymer-specific data.
{"title":"TG-FTIR investigations of the pyrolysis of polyurethanes: Quantitative carbon dioxide tracing, decomposition mechanisms, products and mass balances for advanced recycling","authors":"Michael Zeller, Daniela Merz, Luca Weigel, Salar Tavakkol, Dieter Stapf","doi":"10.1016/j.jaap.2025.107048","DOIUrl":"10.1016/j.jaap.2025.107048","url":null,"abstract":"<div><div>Polyurethanes (PUR) are versatile polymers used in a broad range of applications. Conventional mechanical recycling is thus difficult. Chemical recycling such as pyrolytic waste treatment presents new recycling options. Advanced recycling by pyrolysis may help to reduce environmental impacts from PUR wastes. The knowledge of mechanisms, products and yields is essential for the design of efficient pyrolysis processes. Rigid (RPUF) and flexible foams (FPUF), a cast elastomer (CE) and a thermoplastic Polyurethane (TPU) have been investigated by thermogravimetry (TG) and FTIR-spectroscopy. Two decomposition steps have been identified. CO<sub>2</sub> is mainly released in the first decomposition step between 250 °C and 400 °C. The second decomposition step at temperatures above 400 °C releases polyol fragments and marginal amounts of CO<sub>2</sub>. Strong feedstock dependency is evident. Quantitative tracing for the CO<sub>2</sub> release was developed, validated and applied. This allows the resolution of specific decomposition phenomena, mass balancing and distinguishing potentially valuable volatiles from CO<sub>2</sub> and solid residues. CO<sub>2</sub> yields are 12.0 mass-% for RPUF, 4.0 mass-% for FPUF, 3.2 mass-% for CE and 5.3 mass-% for TPU. Considering solids and CO<sub>2</sub> as losses, recycling potentials were determined which are 74 mass-% for RPUF, 90 mass-% for FPUF, 95 mass% for CE and 93 mass-% for TPU. This facilitates further process development based on polymer-specific data.</div></div>","PeriodicalId":345,"journal":{"name":"Journal of Analytical and Applied Pyrolysis","volume":"188 ","pages":"Article 107048"},"PeriodicalIF":5.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479590","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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