Pub Date : 2024-04-30DOI: 10.1016/j.fuproc.2024.108093
Xiaosong Luo, Qibin Li
In order to understand the effect of traditional solvents on lignin pyrolysis, the decarbonylation and decarboxylation reactions of various phenylic lignin model compounds were theoretically investigated using DFT methods at M06-2×/6–31++G(d,p) level. The calculation results show that activation energy of the decarbonylation and decarboxylation reactions of lignin model compounds can be reduced when H2O/CH3OH existed. There are two types of reaction for the H2O/CH3OH during the pyrolysis. For first type, the synergistic reaction of lignin with H2O/CH3OH as hydrogen transfer carrier. The energy barriers of the main elemental reaction steps during this type of pyrolysis are about 285.0–300.0 kJ/mol (H2O) and 275.0–290.0 kJ/mol (CH3OH) (decarbonylation), 170.0–210.0 kJ/mol and 155.0–200.0 kJ/mol (decarboxylation). For another type, the synergistic reaction of lignin with H2O/CH3OH as hydrogen source. The energy barriers of the main elemental reaction steps during this type of pyrolysis are about 260.0–278.0 kJ/mol and 240.0–260.0 kJ/mol, 303.0–312.0 kJ/mol and 291.0–297.0 kJ/mol. Furthermore, the reaction temperature has the most significant impact on decomposition reaction of lignin in a methanol medium, suggesting that the reaction in the methanol medium is better than that in the water environment.
{"title":"Effect of traditional solvent on thermal decomposition mechanism of lignin: A density functional theory study","authors":"Xiaosong Luo, Qibin Li","doi":"10.1016/j.fuproc.2024.108093","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108093","url":null,"abstract":"<div><p>In order to understand the effect of traditional solvents on lignin pyrolysis, the decarbonylation and decarboxylation reactions of various phenylic lignin model compounds were theoretically investigated using DFT methods at M06-2×/6–31++G(d,p) level. The calculation results show that activation energy of the decarbonylation and decarboxylation reactions of lignin model compounds can be reduced when H<sub>2</sub>O/CH<sub>3</sub>OH existed. There are two types of reaction for the H<sub>2</sub>O/CH<sub>3</sub>OH during the pyrolysis. For first type, the synergistic reaction of lignin with H<sub>2</sub>O/CH<sub>3</sub>OH as hydrogen transfer carrier. The energy barriers of the main elemental reaction steps during this type of pyrolysis are about 285.0–300.0 kJ/mol (H<sub>2</sub>O) and 275.0–290.0 kJ/mol (CH<sub>3</sub>OH) (decarbonylation), 170.0–210.0 kJ/mol and 155.0–200.0 kJ/mol (decarboxylation). For another type, the synergistic reaction of lignin with H<sub>2</sub>O/CH<sub>3</sub>OH as hydrogen source. The energy barriers of the main elemental reaction steps during this type of pyrolysis are about 260.0–278.0 kJ/mol and 240.0–260.0 kJ/mol, 303.0–312.0 kJ/mol and 291.0–297.0 kJ/mol. Furthermore, the reaction temperature has the most significant impact on decomposition reaction of lignin in a methanol medium, suggesting that the reaction in the methanol medium is better than that in the water environment.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"258 ","pages":"Article 108093"},"PeriodicalIF":7.5,"publicationDate":"2024-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000638/pdfft?md5=7d96e6eec487bcd5d81a3624fc64c316&pid=1-s2.0-S0378382024000638-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140815395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper explores pyrolysis potential for effective modified biochar (MB) production, serving as a green and novel carbon-based catalyst support in Fischer-Tropsch to olefins synthesis. For this purpose, the MB produced from the pyrolysis of pre-treated Peanut shell (PS) and Cladophora glomerata algae (CG) was used as a high porosity support for cobalt catalyst synthesis. The impregnation technique was applied to prepare the cobalt catalysts, and the catalysts were promoted with potassium. Various methods examine catalysts physico-chemical properties. After 10 h of reduction at 400 °C, the catalysts' activity and selectivity were studied in a fixed-bed reactor. TEM images show that the metal particles are suitably distributed on the porous surface of the modified biochars. The majority of the particles were between 5 and 15 nm in size. Also, TPR results indicate a suitable metal dispersion of about 10% and good catalyst reducibility have been achieved. The cobalt catalysts produced on MBs of CG and PS exhibited FT rates of 0.245 and 0.223 (g HC/g cat.h), with CO conversion rates of 50.25% and 45.68% in each case. Finally, K-promoted cobalt catalysts supported on MBs of CG and PS showed the α-olefins selectivities of 38.67% and 35.49% for C2-C13 hydrocarbons, respectively.
{"title":"Green catalyst innovation: Enhanced Fischer-Tropsch synthesis using potassium-promoted cobalt catalysts supported on pyrolyzed peanut shells and Cladophora Glomerata modified biochars","authors":"Fatemeh Bayat , S.M. Pirbazari , Nastaran Shojaei , Shiva Kiani , Ahmad Tavasoli","doi":"10.1016/j.fuproc.2024.108094","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108094","url":null,"abstract":"<div><p>This paper explores pyrolysis potential for effective modified biochar (MB) production, serving as a green and novel carbon-based catalyst support in Fischer-Tropsch to olefins synthesis. For this purpose, the MB produced from the pyrolysis of pre-treated Peanut shell (PS) and <em>Cladophora glomerata</em> algae (CG) was used as a high porosity support for cobalt catalyst synthesis. The impregnation technique was applied to prepare the cobalt catalysts, and the catalysts were promoted with potassium. Various methods examine catalysts physico-chemical properties. After 10 h of reduction at 400 °C, the catalysts' activity and selectivity were studied in a fixed-bed reactor. TEM images show that the metal particles are suitably distributed on the porous surface of the modified biochars. The majority of the particles were between 5 and 15 nm in size. Also, TPR results indicate a suitable metal dispersion of about 10% and good catalyst reducibility have been achieved. The cobalt catalysts produced on MBs of CG and PS exhibited FT rates of 0.245 and 0.223 (g HC/g cat.h), with CO conversion rates of 50.25% and 45.68% in each case. Finally, K-promoted cobalt catalysts supported on MBs of CG and PS showed the α-olefins selectivities of 38.67% and 35.49% for C2-C13 hydrocarbons, respectively.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"258 ","pages":"Article 108094"},"PeriodicalIF":7.5,"publicationDate":"2024-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S037838202400064X/pdfft?md5=cc2d8473c9367e66eaed8cf09e5f78e5&pid=1-s2.0-S037838202400064X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140807874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-26DOI: 10.1016/j.fuproc.2024.108091
Pavel Milčák, Marek Baláš, Martin Lisý, Hana Lisá, Petr Kracík, Jakub Lachman
Digestate is the secondary product of the fermentation process in biogas plants. The use of digestate as a fertilizer is very common. However, this is more and more limited nowadays and therefore alternative uses for digestate are sought. The research described in this article maps the possibilities of using digestate from the wet fermentation process for the syngas generation. This work is focuses on the gasification of the digestate with spruce chips mixtures. The mixtures were prepared with a proportion of 0, 25, 50, 75 and 100% of the digestate. The experiments were carried out on a semi-operational fluidized bed gasifier at atmospheric pressure. The working temperature of the fluidized bed was 810 °C; the gasification was autothermal. The gasification was carried out with three types of gasification agents, i.e. air, air-steam, and oxygen-steam for each fuel mixture. The aim of the research was to assess the effect of the digestate with wood chips on the qualitative and quantitative properties of the syngas. The digestate can be characterized as a secondary energy source reducing the consumption of primary energy sources. The produced syngas is of high quality and the digestate can become a very desirable fuel for the syngas production.
{"title":"Digestate and woodchips gasification: A comparison of different gasifying agents","authors":"Pavel Milčák, Marek Baláš, Martin Lisý, Hana Lisá, Petr Kracík, Jakub Lachman","doi":"10.1016/j.fuproc.2024.108091","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108091","url":null,"abstract":"<div><p>Digestate is the secondary product of the fermentation process in biogas plants. The use of digestate as a fertilizer is very common. However, this is more and more limited nowadays and therefore alternative uses for digestate are sought. The research described in this article maps the possibilities of using digestate from the wet fermentation process for the syngas generation. This work is focuses on the gasification of the digestate with spruce chips mixtures. The mixtures were prepared with a proportion of 0, 25, 50, 75 and 100% of the digestate. The experiments were carried out on a semi-operational fluidized bed gasifier at atmospheric pressure. The working temperature of the fluidized bed was 810 °C; the gasification was autothermal. The gasification was carried out with three types of gasification agents, i.e. air, air-steam, and oxygen-steam for each fuel mixture. The aim of the research was to assess the effect of the digestate with wood chips on the qualitative and quantitative properties of the syngas. The digestate can be characterized as a secondary energy source reducing the consumption of primary energy sources. The produced syngas is of high quality and the digestate can become a very desirable fuel for the syngas production.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"258 ","pages":"Article 108091"},"PeriodicalIF":7.5,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000614/pdfft?md5=e33a614c7b223b61fed86a66d715ec51&pid=1-s2.0-S0378382024000614-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140806967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work pyrolysis of palm oil and lignin has been investigated using a two-stage process at 550 °C, with a first step configuration of continuous condensation for vapors and separation of gases, and a second step with distillation of vapors. Experiments were realized as pyrolysis of palm oil, palmitic acid, and Kraft lignin, as well as co-pyrolysis of palm oil/lignin, palmitic acid/lignin and palmitic acid/guaiacol. It has been shown that the addition of lignin improves the quality of palm oil pyrolysis bio-oil, thanks to the conversion of fatty acids coproduct to fatty acid methyl esters (FAME). The production of methyl esters in the reaction environment using palm oil and lignin was studied by conducting experiments with palmitic acid and lignin, as well as palmitic acid and guaiacol (the main product obtained from lignin pyrolysis). The results highlighted that during pyrolysis, the production of FAME is a consequence of a direct esterification reaction on palmitic acid. The formation of FAMEs during pyrolysis presents a promising avenue to optimize the utilization of palm oil by generating FAMEs as supplementary fuel products, Furthermore, it is possible to consider the application of the studied process for the conversion of free fatty acids into FAME.
在这项工作中,研究人员在 550 °C 温度下采用两步法热解棕榈油和木质素,第一步是连续冷凝蒸汽和分离气体,第二步是蒸馏蒸汽。实验实现了棕榈油、棕榈酸和牛皮纸木质素的热解,以及棕榈油/木质素、棕榈酸/木质素和棕榈酸/愈创木酚的共热解。研究表明,添加木质素可将脂肪酸副产品转化为脂肪酸甲酯(FAME),从而提高棕榈油热解生物油的质量。通过对棕榈酸和木质素以及棕榈酸和愈创木酚(木质素热解产生的主要产品)进行实验,研究了在使用棕榈油和木质素的反应环境中产生甲酯的情况。研究结果表明,在热解过程中,棕榈酸直接发生酯化反应生成了二甲醚。在热解过程中形成的二甲醚为优化棕榈油的利用提供了一个很有前景的途径,它可以产生二甲醚作为补充燃料产品,此外,还可以考虑应用所研究的工艺将游离脂肪酸转化为二甲醚。
{"title":"Two-stage co-pyrolysis of Kraft lignin and palm oil mixture to biofuels: The role of lignin as a methylation agent for methyl ester formation","authors":"Matteo Borella , Alessandro A. Casazza , Guido Busca , Gabriella Garbarino","doi":"10.1016/j.fuproc.2024.108092","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108092","url":null,"abstract":"<div><p>In this work pyrolysis of palm oil and lignin has been investigated using a two-stage process at 550 °C, with a first step configuration of continuous condensation for vapors and separation of gases, and a second step with distillation of vapors. Experiments were realized as pyrolysis of palm oil, palmitic acid, and Kraft lignin, as well as co-pyrolysis of palm oil/lignin, palmitic acid/lignin and palmitic acid/guaiacol. It has been shown that the addition of lignin improves the quality of palm oil pyrolysis bio-oil, thanks to the conversion of fatty acids coproduct to fatty acid methyl esters (FAME). The production of methyl esters in the reaction environment using palm oil and lignin was studied by conducting experiments with palmitic acid and lignin, as well as palmitic acid and guaiacol (the main product obtained from lignin pyrolysis). The results highlighted that during pyrolysis, the production of FAME is a consequence of a direct esterification reaction on palmitic acid. The formation of FAMEs during pyrolysis presents a promising avenue to optimize the utilization of palm oil by generating FAMEs as supplementary fuel products, Furthermore, it is possible to consider the application of the studied process for the conversion of free fatty acids into FAME.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"257 ","pages":"Article 108092"},"PeriodicalIF":7.5,"publicationDate":"2024-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000626/pdfft?md5=1c85b9dcbfcec0c35f2fd9ff0d4a38f6&pid=1-s2.0-S0378382024000626-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140645849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-23DOI: 10.1016/j.fuproc.2024.108090
Qing Li , Bo Tian , Lei Xu , Yu Wang
Co-firing NH3 with conventional hydrocarbon fuels is an important approach for reducing CO2 emissions in existing combustion systems. Besides CO2, the blending of NH3 would also notably affect soot formation and its oxidation behaviors. In the present study, we focus on the effects of NH3 on the nanostructure and oxidation characteristics of soot produced in diffusion flames of n-heptane/toluene mixtures. Two configurations of laminar co-flow diffusion flame, including both normal and inverse diffusion flames (NDF and IDFs), were used for investigation. High-resolution transmission electron microscopy (HRTEM), Raman spectroscopy (Raman), and Thermogravimetric analysis (TGA) were employed for soot characterization. The HRTEM and Raman spectra showed that with the increase of NH3 blending ratio, the fringe length (La) and the degree of graphitization decreased while the microcrystal tortuosity (Tf) increased. The results are in consistent with TGA analysis which suggests the promoting effects of NH3 on the soot oxidation reactivity. Difference between NDF and IDF with respect to the soot nanostructure and oxidation activity were discussed. It is our hope that the present results could deepen our understanding on the effects of NH3 on soot nanostructure and oxidation behavior and benefit the design of particulate filters for combustion devices fueled with hydrocarbon/NH3 mixtures.
{"title":"Effects of ammonia addition on the soot nanostructure and oxidation reactivity in n-heptane/toluene diffusion flames","authors":"Qing Li , Bo Tian , Lei Xu , Yu Wang","doi":"10.1016/j.fuproc.2024.108090","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108090","url":null,"abstract":"<div><p>Co-firing NH<sub>3</sub> with conventional hydrocarbon fuels is an important approach for reducing CO<sub>2</sub> emissions in existing combustion systems. Besides CO<sub>2</sub>, the blending of NH<sub>3</sub> would also notably affect soot formation and its oxidation behaviors. In the present study, we focus on the effects of NH<sub>3</sub> on the nanostructure and oxidation characteristics of soot produced in diffusion flames of <em>n</em>-heptane/toluene mixtures. Two configurations of laminar co-flow diffusion flame, including both normal and inverse diffusion flames (NDF and IDFs), were used for investigation. High-resolution transmission electron microscopy (HRTEM), Raman spectroscopy (Raman), and Thermogravimetric analysis (TGA) were employed for soot characterization. The HRTEM and Raman spectra showed that with the increase of NH<sub>3</sub> blending ratio, the fringe length (<em>L</em><sub>a</sub>) and the degree of graphitization decreased while the microcrystal tortuosity (<em>T</em><sub>f</sub>) increased. The results are in consistent with TGA analysis which suggests the promoting effects of NH<sub>3</sub> on the soot oxidation reactivity. Difference between NDF and IDF with respect to the soot nanostructure and oxidation activity were discussed. It is our hope that the present results could deepen our understanding on the effects of NH<sub>3</sub> on soot nanostructure and oxidation behavior and benefit the design of particulate filters for combustion devices fueled with hydrocarbon/NH<sub>3</sub> mixtures.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"257 ","pages":"Article 108090"},"PeriodicalIF":7.5,"publicationDate":"2024-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000602/pdfft?md5=f61b089f767b1dfdcb543451374cd245&pid=1-s2.0-S0378382024000602-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140638773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-16DOI: 10.1016/j.fuproc.2024.108088
Cahyani Windarto , Ocktaeck Lim
In the current study, we examined the impact of spark duration strategy on a large bore compression ignition engine fueled with propane direct injection. An artificial neural network also was used to forecast engine in-cylinder performance characteristics. A rapid compression and expansion machine (RCEM) with a spark plug was tested with a high-pressure direct injection propane of 200 bar. While the timing of the injection was set to 20 °CA bTDC, the spark duration can range from 0.7 to 5.0 milliseconds. Crank angle degree, pressure, ignition coil number and spark duration were used as input parameters in the ANN model to predict in-cylinder performance, while engine performance parameters such as heat release rate (HRR), turbulent kinetic energy (TKE), tumble ratio, indicated power, and combustion efficiency () were used as output parameters. The ANN model was created using the neural network toolbox and standard backpropagation with the Levenberg-Marquardt training algorithm was used with the learning rate and training epochs of the ANN model set to 0.001 and 1000, respectively. The accuracy of the model was validated by comparing the predicted datasets with the experimental data. The five projected parameters of heat release rate (HRR), turbulent kinetic energy (TKE), tumble ratio, indicated power, and combustion efficiency () showed values of 0.9833, 0.9860, 0.9728, 0.9807, 0.9052, and 0.9999, respectively, and values of 0.1419, 0.0023, 0.6428, 0.0106, 0.0050, and 0.0134. The of the validation dataset was nearly 0.98, which is close to that of the training dataset. The coefficients of determination () were greater than 0.9 in the projected results, and the was reasonably low, indicating that a predictive model based on ANN model could predict in-cylinder performance of a large bore compression ignition engine.
{"title":"A neural network approach on forecasting spark duration effect on in-cylinder performance of a large bore compression ignition engine fueled with propane direct injection","authors":"Cahyani Windarto , Ocktaeck Lim","doi":"10.1016/j.fuproc.2024.108088","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108088","url":null,"abstract":"<div><p>In the current study, we examined the impact of spark duration strategy on a large bore compression ignition engine fueled with propane direct injection. An artificial neural network also was used to forecast engine in-cylinder performance characteristics. A rapid compression and expansion machine (RCEM) with a spark plug was tested with a high-pressure direct injection propane of 200 bar. While the timing of the injection was set to 20 °CA bTDC, the spark duration can range from 0.7 to 5.0 milliseconds. Crank angle degree, pressure, ignition coil number and spark duration were used as input parameters in the ANN model to predict in-cylinder performance, while engine performance parameters such as heat release rate (HRR), turbulent kinetic energy (TKE), tumble ratio, indicated power, and combustion efficiency (<span><math><msub><mi>η</mi><mi>c</mi></msub></math></span>) were used as output parameters. The ANN model was created using the neural network toolbox and standard backpropagation with the Levenberg-Marquardt training algorithm was used with the learning rate and training epochs of the ANN model set to 0.001 and 1000, respectively. The accuracy of the model was validated by comparing the predicted datasets with the experimental data. The five projected parameters of heat release rate (HRR), turbulent kinetic energy (TKE), tumble ratio, indicated power, and combustion efficiency (<span><math><msub><mi>η</mi><mi>c</mi></msub></math></span>) showed <span><math><msup><mi>R</mi><mn>2</mn></msup></math></span> values of 0.9833, 0.9860, 0.9728, 0.9807, 0.9052, and 0.9999, respectively, and <span><math><mi>MSE</mi></math></span> values of 0.1419, 0.0023, 0.6428, 0.0106, 0.0050, and 0.0134. The <span><math><msup><mi>R</mi><mn>2</mn></msup></math></span> of the validation dataset was nearly 0.98, which is close to that of the training dataset. The coefficients of determination (<span><math><msup><mi>R</mi><mn>2</mn></msup></math></span>) were greater than 0.9 in the projected results, and the <span><math><mi>MSE</mi></math></span> was reasonably low, indicating that a predictive model based on ANN model could predict in-cylinder performance of a large bore compression ignition engine.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"257 ","pages":"Article 108088"},"PeriodicalIF":7.5,"publicationDate":"2024-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000584/pdfft?md5=c972f3c6162025038b85108075a98a03&pid=1-s2.0-S0378382024000584-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140555059","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-04-15DOI: 10.1016/j.fuproc.2024.108089
Mumtaj Shah , Mohammed K. Al Mesfer , Mohd Danish , Prasenjit Mondal , Hemant Goyal , Subhasis Das
In this study, Co-based catalysts supported over Ti-Al oxide and promoted with La, Ce, Mg, and K metals were assessed for CO2 reforming of methane reaction to produce syngas. Titania-alumina mixed oxide supports were prepared using the template-assisted-solvothermal method, and then Co and promotors were co-impregnated over the as-prepared support. Different characterizations of catalysts showed that variation in promotor metal impacts these catalysts' physical and chemical properties. The Ti-Al oxide support possessed the perfect hexagonal morphology. Potassium-promoted catalysts possessed the highest number of basic sites, whereas the La-promoted catalyst possessed the highest number of acidic sites. La promotion improved the Co dispersion, while Mg promotion enhanced the metal support integration. La-promoted catalysts are deactivated because of active metal oxidation and the generation of hard carbon. The carbon was deposited in all catalysts; however, the activity of the Mg-promoted catalyst was unaffected. The intermediate surface basicity and strong metal support interaction improved the Mg-promoted catalyst's stability. The La and Mg-promoted catalysts possessed lower apparent activation energies.
本研究评估了以钛铝氧化物为载体并以 La、Ce、Mg 和 K 金属为促进剂的 Co 基催化剂在二氧化碳重整甲烷反应生成合成气中的应用。采用模板辅助溶热法制备了钛铝混合氧化物载体,然后将 Co 和促进剂共同浸渍在制备好的载体上。催化剂的不同特性表明,促进剂金属的变化会影响催化剂的物理和化学特性。钛-铝氧化物载体具有完美的六边形形态。钾促进的催化剂具有最多的碱性位点,而喇促进的催化剂具有最多的酸性位点。La 促进改善了 Co 的分散,而 Mg 促进则提高了金属支撑的整合。由于活性金属氧化并生成硬碳,La 促进的催化剂失活。碳沉积在所有催化剂中;然而,镁促进催化剂的活性未受影响。中间表面碱性和强金属支撑相互作用提高了镁促进催化剂的稳定性。La 和 Mg 促进的催化剂具有较低的表观活化能。
{"title":"Study on the effect of promotors in CO2 utilization for syngas production via dry reforming of methane over Co-MOX/TiO2-Al2O3 (MOX = La, Ce, Mg, and K) catalysts","authors":"Mumtaj Shah , Mohammed K. Al Mesfer , Mohd Danish , Prasenjit Mondal , Hemant Goyal , Subhasis Das","doi":"10.1016/j.fuproc.2024.108089","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108089","url":null,"abstract":"<div><p>In this study, Co-based catalysts supported over Ti-Al oxide and promoted with La, Ce, Mg, and K metals were assessed for CO<sub>2</sub> reforming of methane reaction to produce syngas. Titania-alumina mixed oxide supports were prepared using the template-assisted-solvothermal method, and then Co and promotors were co-impregnated over the as-prepared support. Different characterizations of catalysts showed that variation in promotor metal impacts these catalysts' physical and chemical properties. The Ti-Al oxide support possessed the perfect hexagonal morphology. Potassium-promoted catalysts possessed the highest number of basic sites, whereas the La-promoted catalyst possessed the highest number of acidic sites. La promotion improved the Co dispersion, while Mg promotion enhanced the metal support integration. La-promoted catalysts are deactivated because of active metal oxidation and the generation of hard carbon. The carbon was deposited in all catalysts; however, the activity of the Mg-promoted catalyst was unaffected. The intermediate surface basicity and strong metal support interaction improved the Mg-promoted catalyst's stability. The La and Mg-promoted catalysts possessed lower apparent activation energies.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"257 ","pages":"Article 108089"},"PeriodicalIF":7.5,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000596/pdfft?md5=e7efe114b37183acd9f614bf796f55f6&pid=1-s2.0-S0378382024000596-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140555209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Numerous innovative low-carbon ironmaking technologies rely on the use of a high-temperature, highly reducing gas, with examples including the gas-based direct reduction approach, hydrogen-enriched blast furnace fuel injection, and hydrogen-rich carbon circulation oxygen blast furnaces. However, the process of obtaining high-temperature and highly reducing gases inevitably leads to carbon deposition, and effective methods for controlling carbon deposition have yet to be developed for practical applications. Thus, within the context of metallurgical process conditions, this article provides a comprehensive review of the advancements in carbon deposition research by integrating findings from the fields of fuel chemistry and carbon material synthesis. Initially, the thermodynamic fundamentals of the carbon deposition reactions are examined, and subsequently, the influences of temperature, H2, and catalysis on the carbon deposition reactions are discussed. In addition, the growth and erosion mechanisms of carbon on the surface of the medium are analyzed. Finally, this review consolidates the methods available for controlling carbon deposition, encompassing changes in the process conditions, the development of anti-carbon materials, and research into special processes. This article also identifies gaps in the literature and outlines future directions in related fields, notably proposing the application prospects of the sulfur passivation and thermal plasma reforming technologies in the reforming and heating of highly reducing gases.
{"title":"Advancements in the study of carbon deposition behavior during the metallurgical high-reductive potential gas reforming and heating processes","authors":"Xingjian Deng, Lianda Zhao, Tian Gao, Qingguo Xue, Jingsong Wang, Haibin Zuo","doi":"10.1016/j.fuproc.2024.108087","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108087","url":null,"abstract":"<div><p>Numerous innovative low-carbon ironmaking technologies rely on the use of a high-temperature, highly reducing gas, with examples including the gas-based direct reduction approach, hydrogen-enriched blast furnace fuel injection, and hydrogen-rich carbon circulation oxygen blast furnaces. However, the process of obtaining high-temperature and highly reducing gases inevitably leads to carbon deposition, and effective methods for controlling carbon deposition have yet to be developed for practical applications. Thus, within the context of metallurgical process conditions, this article provides a comprehensive review of the advancements in carbon deposition research by integrating findings from the fields of fuel chemistry and carbon material synthesis. Initially, the thermodynamic fundamentals of the carbon deposition reactions are examined, and subsequently, the influences of temperature, H<sub>2</sub>, and catalysis on the carbon deposition reactions are discussed. In addition, the growth and erosion mechanisms of carbon on the surface of the medium are analyzed. Finally, this review consolidates the methods available for controlling carbon deposition, encompassing changes in the process conditions, the development of anti-carbon materials, and research into special processes. This article also identifies gaps in the literature and outlines future directions in related fields, notably proposing the application prospects of the sulfur passivation and thermal plasma reforming technologies in the reforming and heating of highly reducing gases.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"257 ","pages":"Article 108087"},"PeriodicalIF":7.5,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000572/pdfft?md5=f7cb4b9ec15ba6fa6c2e79573920fe12&pid=1-s2.0-S0378382024000572-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140544004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The high-value recycling of discarded phenol-formaldehyde resins (PF) remains an unresolved challenge. Herein, we propose a novel approach leveraging γ-Al2O3 to convert PF into high-value hexamethylbenzene at a low temperature using a one-pot method. This study explores the degradation capability of PF, methylation reaction efficiency, and hydrodeoxygenation capacity among various cost-effective commercial catalysts: γ-Al2O3, ZrO2, and TiO2. It reveals the influence of different reaction times on PF pyrolysis and product distribution, and it was found that high value-added hexamethylbenzene exhibited the highest yield (73.33 wt%) with selectivity (75.83%) using γ-Al2O3 at 350 °C and 2 h of reaction. Experiments using PF models demonstrate the crucial synergy between γ-Al2O3 and C(aryl)-OH in the cleavage of C(aryl)-C(alkyl) bonds and methylation reactions. A pathway for PF C-C/C-O bonds cleavage-methylation tandem reaction is proposed, based on 13C methanol isotope experiments. PF undergoes C(aryl)-C(alkyl) bond cleavage to produce phenolic intermediates, which were then methylated; this is accompanied by the cleavage of C(aryl)-OH and C(aryl)-OCH3, culminating in C-alkylation to form hexamethylbenzene. This research provides new insights into the high-value recycling of PF.
{"title":"Mechanistic understanding of the C-C/C-O bonds cleavage-methylation tandem reaction for the conversion of phenolic resins to hexamethylbenzene using γ-Al2O3","authors":"Gangqi Cheng , Xueru Chen , Ruizhe Chen , Jialiang Yang , Leilei Cheng , Jing Gu","doi":"10.1016/j.fuproc.2024.108086","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108086","url":null,"abstract":"<div><p>The high-value recycling of discarded phenol-formaldehyde resins (PF) remains an unresolved challenge. Herein, we propose a novel approach leveraging γ-Al<sub>2</sub>O<sub>3</sub> to convert PF into high-value hexamethylbenzene at a low temperature using a one-pot method. This study explores the degradation capability of PF, methylation reaction efficiency, and hydrodeoxygenation capacity among various cost-effective commercial catalysts: γ-Al<sub>2</sub>O<sub>3</sub>, ZrO<sub>2</sub>, and TiO<sub>2</sub>. It reveals the influence of different reaction times on PF pyrolysis and product distribution, and it was found that high value-added hexamethylbenzene exhibited the highest yield (73.33 wt%) with selectivity (75.83%) using γ-Al<sub>2</sub>O<sub>3</sub> at 350 °C and 2 h of reaction. Experiments using PF models demonstrate the crucial synergy between γ-Al<sub>2</sub>O<sub>3</sub> and C(aryl)-OH in the cleavage of C(aryl)-C(alkyl) bonds and methylation reactions. A pathway for PF C-C/C-O bonds cleavage-methylation tandem reaction is proposed, based on <sup>13</sup>C methanol isotope experiments. PF undergoes C(aryl)-C(alkyl) bond cleavage to produce phenolic intermediates, which were then methylated; this is accompanied by the cleavage of C(aryl)-OH and C(aryl)-OCH<sub>3</sub>, culminating in C-alkylation to form hexamethylbenzene. This research provides new insights into the high-value recycling of PF.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"257 ","pages":"Article 108086"},"PeriodicalIF":7.5,"publicationDate":"2024-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000560/pdfft?md5=bdaadfe3ab936f2557af35447ad3d494&pid=1-s2.0-S0378382024000560-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140330956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-03-20DOI: 10.1016/j.fuproc.2024.108076
Yu Zhang, Chunmu Guo, Wei Wang, Chang Xu, Wei Wu
The hydroisomerization of long-chain n-alkanes proves to be an effective approach for the production of renewable second-generation biodiesel, and the development of bifunctional catalysts with synergistic effect between metal and acidic sites was the key to increase the yield of iso‐alkanes. Herein, novel hierarchical SAPO-31 nanoparticles (S31-Hi) were synthesized with varied amounts of the growth inhibitor 1-octyl-3-methylimidazolium chloride ionic liquid (OMIMCl IL) in a one-stage crystallization, and a proposed formation process was discussed. The 0.1Pd/S31-Hi bifunctional catalysts were prepared by loading only 0.1 wt% Pd based on the S31-Hi by wetness impregnation method and their catalytic performances were evaluated for the hydroisomerization of n-hexadecane. The catalytic performance of 0.1Pd/S31-H based on the S31-H synthesized by adding an appropriate amount of OMIMCl ILs was significantly improved, which can be attributed to the enhanced diffusion originating from its smaller crystal size, higher Pd dispersion, and larger CPd/CH+ value, which was beneficial for achieving synergistic catalysis. The iso‐hexadecane yield of 77.8% and proportion of multi-branched isomers of 51.5%, and catalytic stability within 100 h time on stream was obtained over the 0.1Pd/S31-H at n-hexadecane conversion of 89.3%. These catalysts have application potential for the production of second-generation clean biodiesel with excellent low temperature fluidity.
{"title":"Effect of diffusion and metal-acid synergy on catalytic behavior of the Pd/Hierarchical SAPO-31 nanoparticles for hydroisomerization of n-hexadecane","authors":"Yu Zhang, Chunmu Guo, Wei Wang, Chang Xu, Wei Wu","doi":"10.1016/j.fuproc.2024.108076","DOIUrl":"https://doi.org/10.1016/j.fuproc.2024.108076","url":null,"abstract":"<div><p>The hydroisomerization of long-chain <em>n</em>-alkanes proves to be an effective approach for the production of renewable second-generation biodiesel, and the development of bifunctional catalysts with synergistic effect between metal and acidic sites was the key to increase the yield of <em>iso</em>‐alkanes. Herein, novel hierarchical SAPO-31 nanoparticles (S31-H<em>i</em>) were synthesized with varied amounts of the growth inhibitor 1-octyl-3-methylimidazolium chloride ionic liquid (OMIMCl IL) in a one-stage crystallization, and a proposed formation process was discussed. The 0.1Pd/S31-H<em>i</em> bifunctional catalysts were prepared by loading only 0.1 wt% Pd based on the S31-H<em>i</em> by wetness impregnation method and their catalytic performances were evaluated for the hydroisomerization of <em>n</em>-hexadecane. The catalytic performance of 0.1Pd/S31-H based on the S31-H synthesized by adding an appropriate amount of OMIMCl ILs was significantly improved, which can be attributed to the enhanced diffusion originating from its smaller crystal size, higher Pd dispersion, and larger C<sub>Pd</sub>/C<sub>H</sub><sub>+</sub> value, which was beneficial for achieving synergistic catalysis. The <em>iso</em>‐hexadecane yield of 77.8% and proportion of multi-branched isomers of 51.5%, and catalytic stability within 100 h time on stream was obtained over the 0.1Pd/S31-H at <em>n</em>-hexadecane conversion of 89.3%. These catalysts have application potential for the production of second-generation clean biodiesel with excellent low temperature fluidity.</p></div>","PeriodicalId":326,"journal":{"name":"Fuel Processing Technology","volume":"256 ","pages":"Article 108076"},"PeriodicalIF":7.5,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378382024000468/pdfft?md5=6b8659cd3c3c4e0f27965ec41c1cba66&pid=1-s2.0-S0378382024000468-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140180978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}