Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101931
Ye Tian, Wenze Liu, Chongzhe Zeng, Xiong Zhou, Shihan Du, Yihao Wang, Heng Li
Co-gasification of biomass and MSW represents an effective approach for the waste recovery and carbon emission reduction. The optimal conditions for biomass/MSW gasification is important in planning large–scale setups. Here, an experimental study was conducted in a lab-scale fluidized bed gasification system at various temperatures (700–850 °C), steam/feedstock ratio (S/F: 0.25–1.0), MSW mixing ratio (MMR: 0–100 %) and Ni contents (0–20 %) for H2-rich gas production. Ni/dolomite was selected as an in-bed material for tar reformer and solid absorption. The motivation of this work is to find out the suitable conditions for obtaining high-quality and low-tar syngas appropriate to use in engineering applications. Compared with calcined dolomite, Ni/dolomite revealed better catalytic activity in terms of tar modification. The results showed that there is an optimal value for Ni content. Increasing Ni content from 0 to 15 % resulted in more H2 production, higher gas yield (Yg) and lower tar yield (YT). However, a slight reduction in the catalytic activity of Ni/dolomite with a further increase of Ni content from 15 % to 20 % was observed, probably due to a slight coke deposition on Ni/dolomite catalyst for Ni content> 15 %. With the growth of MSW content, YG showed a slight variation due to a slight change in carbon content of biomass-MSW mixtures at high MMRs.
{"title":"Experimental study on steam co-gasification of biomass/municipal solid waste (MSW) for H2-rich gas production","authors":"Ye Tian, Wenze Liu, Chongzhe Zeng, Xiong Zhou, Shihan Du, Yihao Wang, Heng Li","doi":"10.1016/j.joei.2024.101931","DOIUrl":"10.1016/j.joei.2024.101931","url":null,"abstract":"<div><div>Co-gasification of biomass and MSW represents an effective approach for the waste recovery and carbon emission reduction. The optimal conditions for biomass/MSW gasification is important in planning large–scale setups. Here, an experimental study was conducted in a lab-scale fluidized bed gasification system at various temperatures (700–850 °C), steam/feedstock ratio (S/F: 0.25–1.0), MSW mixing ratio (MMR: 0–100 %) and Ni contents (0–20 %) for H<sub>2</sub>-rich gas production. Ni/dolomite was selected as an in-bed material for tar reformer and solid absorption. The motivation of this work is to find out the suitable conditions for obtaining high-quality and low-tar syngas appropriate to use in engineering applications. Compared with calcined dolomite, Ni/dolomite revealed better catalytic activity in terms of tar modification. The results showed that there is an optimal value for Ni content. Increasing Ni content from 0 to 15 % resulted in more H<sub>2</sub> production, higher gas yield (Y<sub>g</sub>) and lower tar yield (Y<sub>T</sub>). However, a slight reduction in the catalytic activity of Ni/dolomite with a further increase of Ni content from 15 % to 20 % was observed, probably due to a slight coke deposition on Ni/dolomite catalyst for Ni content> 15 %. With the growth of MSW content, Y<sub>G</sub> showed a slight variation due to a slight change in carbon content of biomass-MSW mixtures at high MMRs.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101931"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101910
Sunyong Park , Seok Jun Kim , Kwang Cheol Oh , Seon Yeop Kim , Ha Eun Kim , DaeHyun Kim
Biomass utilization as an alternative to fossil fuels is increasingly prioritized due to its potential to mitigate environmental pollution and enhance energy security. Torrefaction, a thermochemical process conducted under oxygen-lean conditions, improves biomass fuel quality by increasing energy density and hydrophobicity. However, optimizing this process requires a comprehensive understanding of biomass changes, particularly mass loss and its impact on elemental composition, proximate analysis, and energy indices. This study developed a predictive model that leverages enhancement ratio criterions to improve accuracy in forecasting changes during torrefaction. The proposed model exhibited superior performance compared to previous approaches, achieving an R2 of 0.9725 for energy yield and 0.9339 for energy density enhancement factor. Distinct trends were observed, with a linear relationship for energy yield and logarithmic correlations for other parameters. The findings emphasize the importance of tailoring torrefaction conditions based on biomass types (e.g., herbaceous or lignocellulosic) to achieve optimal energy output. Compared to earlier models, this approach demonstrated higher precision and broader applicability by incorporating characteristics of untreated biomass. This research provides a robust framework for sustainable energy production, advancing the field of bioenergy and offering valuable insights for future studies targeting efficient biomass utilization and process optimization.
{"title":"Predictive modelling of lignocellulosic biomass fuel changes during torrefaction via mass reduction","authors":"Sunyong Park , Seok Jun Kim , Kwang Cheol Oh , Seon Yeop Kim , Ha Eun Kim , DaeHyun Kim","doi":"10.1016/j.joei.2024.101910","DOIUrl":"10.1016/j.joei.2024.101910","url":null,"abstract":"<div><div>Biomass utilization as an alternative to fossil fuels is increasingly prioritized due to its potential to mitigate environmental pollution and enhance energy security. Torrefaction, a thermochemical process conducted under oxygen-lean conditions, improves biomass fuel quality by increasing energy density and hydrophobicity. However, optimizing this process requires a comprehensive understanding of biomass changes, particularly mass loss and its impact on elemental composition, proximate analysis, and energy indices. This study developed a predictive model that leverages enhancement ratio criterions to improve accuracy in forecasting changes during torrefaction. The proposed model exhibited superior performance compared to previous approaches, achieving an R<sup>2</sup> of 0.9725 for energy yield and 0.9339 for energy density enhancement factor. Distinct trends were observed, with a linear relationship for energy yield and logarithmic correlations for other parameters. The findings emphasize the importance of tailoring torrefaction conditions based on biomass types (e.g., herbaceous or lignocellulosic) to achieve optimal energy output. Compared to earlier models, this approach demonstrated higher precision and broader applicability by incorporating characteristics of untreated biomass. This research provides a robust framework for sustainable energy production, advancing the field of bioenergy and offering valuable insights for future studies targeting efficient biomass utilization and process optimization.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101910"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101914
Lei Shi , Yinhai Su , Liren Yang , Yuanquan Xiong , Shuping Zhang
Using metal-zeolite catalysts to improve the catalytic efficiency for tar cracking during biomass pyrolysis has attracted a lot of attention of scholars. Herein, the Ni@ZSM-5 catalyst with a hollow structure encapsulating Ni metal was synthesized by hydrothermal-recrystallization. The properties of the catalysts were evaluated by a series of characterization and compared with the solid ZSM-5 as well as nickel loaded ZSM-5. Through TEM observation, it was found that a regular cavity was constructed inside ZSM-5 with Ni particles encapsulated in it successfully. The unique hollow structure facilitated Ni@ZSM-5 owning greater Brønsted acidity and coke resistance, presenting a great activity and stability in tar catalytic cracking. The microporous shell prevented the sintering and loss of Ni significantly. Tar removal efficiency reached 92.2 %, and remained around 90 % after 10 cycles. Pyrolysis gas yield increased by 27.2 %, simultaneously. The reasons for excellent catalyst performance was analyzed as well as the potential evolutionary mechanism for tar molecule over Ni@ZSM-5. The utilization of this unique catalyst provides a reference in the field of biomass utilization.
{"title":"Enhancing the tar removal efficiency and gas production for the pyrolysis of biomass through the nickel-based hollow zeolite","authors":"Lei Shi , Yinhai Su , Liren Yang , Yuanquan Xiong , Shuping Zhang","doi":"10.1016/j.joei.2024.101914","DOIUrl":"10.1016/j.joei.2024.101914","url":null,"abstract":"<div><div>Using metal-zeolite catalysts to improve the catalytic efficiency for tar cracking during biomass pyrolysis has attracted a lot of attention of scholars. Herein, the Ni@ZSM-5 catalyst with a hollow structure encapsulating Ni metal was synthesized by hydrothermal-recrystallization. The properties of the catalysts were evaluated by a series of characterization and compared with the solid ZSM-5 as well as nickel loaded ZSM-5. Through TEM observation, it was found that a regular cavity was constructed inside ZSM-5 with Ni particles encapsulated in it successfully. The unique hollow structure facilitated Ni@ZSM-5 owning greater Brønsted acidity and coke resistance, presenting a great activity and stability in tar catalytic cracking. The microporous shell prevented the sintering and loss of Ni significantly. Tar removal efficiency reached 92.2 %, and remained around 90 % after 10 cycles. Pyrolysis gas yield increased by 27.2 %, simultaneously. The reasons for excellent catalyst performance was analyzed as well as the potential evolutionary mechanism for tar molecule over Ni@ZSM-5. The utilization of this unique catalyst provides a reference in the field of biomass utilization.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101914"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101926
Jiatao Xiang , Xiong Zhang , Han Zhang , Anmin Dong , Shaohui Ren , Shihong Zhang , Jing'ai Shao , Xianhua Wang , Haiping Yang , Hanping Chen
Asphalt rock, characterized by high viscosity and low grade, poses challenges in fuel feeding and is prone to ash deposition and slagging in boilers. Low-temperature oxidation (LTO) is a promising method for modifying and upgrading inferior fuels. In this study, orthogonal experiments were conducted to determine the optimal LTO conditions and assess its effects on the bonding and combustion characteristics of asphalt rock. The results indicate that the optimal LTO conditions are an oxidation temperature of 240 °C, oxidation time of 20 min, and particle size of 1.0–1.4 mm. Under these conditions, the initial bonding temperature (IBT) of asphalt rock increases to 255 °C, a 35 °C improvement over the untreated sample (220 °C) of the control group (CG), while the weight loss ratio (WLR) is 2.52 %. The oxidation temperature has the most significant impact on both IBT and WLR. When subjected to LTO at 240 °C, the asphalt rock exhibits improved combustion characteristics, with better values for DTGmax, DTGmean, ignition temperature (Ti), peak temperature (Tp), ignition index (Di), and comprehensive combustion index (CCI), compared to the CG. However, the burnout temperature (Tb) and burnout index (Db) are slightly lower than those of CG. Furthermore, both the activation energy (Ea) and frequency factor (A) of asphalt rock increase after LTO, suggesting a significant enhancement in its combustion characteristics. Therefore, LTO proves to be an effective and promising method for improving the bonding and combustion characteristics of asphalt rock.
{"title":"Effect of low-temperature oxidation on the bonding and combustion characteristics of asphalt rock","authors":"Jiatao Xiang , Xiong Zhang , Han Zhang , Anmin Dong , Shaohui Ren , Shihong Zhang , Jing'ai Shao , Xianhua Wang , Haiping Yang , Hanping Chen","doi":"10.1016/j.joei.2024.101926","DOIUrl":"10.1016/j.joei.2024.101926","url":null,"abstract":"<div><div>Asphalt rock, characterized by high viscosity and low grade, poses challenges in fuel feeding and is prone to ash deposition and slagging in boilers. Low-temperature oxidation (LTO) is a promising method for modifying and upgrading inferior fuels. In this study, orthogonal experiments were conducted to determine the optimal LTO conditions and assess its effects on the bonding and combustion characteristics of asphalt rock. The results indicate that the optimal LTO conditions are an oxidation temperature of 240 °C, oxidation time of 20 min, and particle size of 1.0–1.4 mm. Under these conditions, the initial bonding temperature (<em>IBT</em>) of asphalt rock increases to 255 °C, a 35 °C improvement over the untreated sample (220 °C) of the control group (CG), while the weight loss ratio (<em>WLR</em>) is 2.52 %. The oxidation temperature has the most significant impact on both <em>IBT</em> and <em>WLR</em>. When subjected to LTO at 240 °C, the asphalt rock exhibits improved combustion characteristics, with better values for <em>DTG</em><sub><em>max</em></sub>, <em>DTG</em><sub><em>mean</em></sub>, ignition temperature (<em>T</em><sub><em>i</em></sub>), peak temperature (<em>T</em><sub><em>p</em></sub>), ignition index (<em>D</em><sub><em>i</em></sub>), and comprehensive combustion index (<em>CCI</em>), compared to the CG. However, the burnout temperature (<em>T</em><sub><em>b</em></sub>) and burnout index (<em>D</em><sub><em>b</em></sub>) are slightly lower than those of CG. Furthermore, both the activation energy (<em>E</em><sub><em>a</em></sub>) and frequency factor (<em>A</em>) of asphalt rock increase after LTO, suggesting a significant enhancement in its combustion characteristics. Therefore, LTO proves to be an effective and promising method for improving the bonding and combustion characteristics of asphalt rock.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101926"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101936
Alexander Backa , Nikola Čajová Kantová , Radovan Nosek , Marek Patsch
The increasing demand for renewable energy sources has increased interest in utilizing agricultural residues as a sustainable fuel alternative for small-scale heating systems. This study examined the combustion of various agricultural pellets — wheat straw, hay, alfalfa, as well as spruce pellets — in a household underfeed 18 kW burner designed for wood pellets. The aim was to evaluate emissions and ash behavior under different air supply settings to identify the most efficient combustion conditions in terms of performance, emissions, and sintered ash formation while minimizing environmental impacts. While adjustments to the air supply could not fully prevent ash sintering, they played a crucial role in optimizing emission and performance parameters. Measurements of CO, NOx, and SO2 emissions, and temperature-related parameters such as burning bed and flame temperatures, were conducted. Altering the air supply setting led to a substantial decrease in device performance, particularly for spruce pellets, where a reduction of up to 2.6 kW was observed at the measured settings. Hay pellets exhibited a significant increase in average CO production from 7944 to 12764 mg/Nm3 and NOx from 307 to 851 mg/Nm3 with varying fan settings. For alfalfa pellets, changes in air supply resulted in higher SO2 emissions, ranging from 1479 to 1683 mg/Nm3. Upon analysis of ashes, Si, K, Ca, and Mg were identified as the predominant elements in the ash from the fuels, along with Cl, S, and P. Among the tested ashes from fuels, wheat straw had the lowest ash deformation temperature at 797.0 ± 9.9 °C, in contrast to alfalfa, which had the highest at 1115.0 ± 19.2 °C. These results highlight the operational challenges of burning agricultural pellets in underfeed pellet burners, particularly given that the average measured burning bed temperature exceeded 1000 °C in some cases.
{"title":"Evaluating the combustion of various biomass pellets in a small heat source with underfeed pellet burner: Heat output, gas emission and ash melting behavior","authors":"Alexander Backa , Nikola Čajová Kantová , Radovan Nosek , Marek Patsch","doi":"10.1016/j.joei.2024.101936","DOIUrl":"10.1016/j.joei.2024.101936","url":null,"abstract":"<div><div>The increasing demand for renewable energy sources has increased interest in utilizing agricultural residues as a sustainable fuel alternative for small-scale heating systems. This study examined the combustion of various agricultural pellets — wheat straw, hay, alfalfa, as well as spruce pellets — in a household underfeed 18 kW burner designed for wood pellets. The aim was to evaluate emissions and ash behavior under different air supply settings to identify the most efficient combustion conditions in terms of performance, emissions, and sintered ash formation while minimizing environmental impacts. While adjustments to the air supply could not fully prevent ash sintering, they played a crucial role in optimizing emission and performance parameters. Measurements of CO, NO<sub>x</sub>, and SO<sub>2</sub> emissions, and temperature-related parameters such as burning bed and flame temperatures, were conducted. Altering the air supply setting led to a substantial decrease in device performance, particularly for spruce pellets, where a reduction of up to 2.6 kW was observed at the measured settings. Hay pellets exhibited a significant increase in average CO production from 7944 to 12764 mg/Nm<sup>3</sup> and NO<sub>x</sub> from 307 to 851 mg/Nm<sup>3</sup> with varying fan settings. For alfalfa pellets, changes in air supply resulted in higher SO<sub>2</sub> emissions, ranging from 1479 to 1683 mg/Nm<sup>3</sup>. Upon analysis of ashes, Si, K, Ca, and Mg were identified as the predominant elements in the ash from the fuels, along with Cl, S, and P. Among the tested ashes from fuels, wheat straw had the lowest ash deformation temperature at 797.0 ± 9.9 °C, in contrast to alfalfa, which had the highest at 1115.0 ± 19.2 °C. These results highlight the operational challenges of burning agricultural pellets in underfeed pellet burners, particularly given that the average measured burning bed temperature exceeded 1000 °C in some cases.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101936"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101928
Rajneesh Yadav, R. Santhosh
The present experimental investigation concerns identification of stable flame regimes and blowout limits of ammonia-hydrogen-nitrogen flames in confined coaxial swirling jet configuration with a confinement ratio () of 1.82. Volumetric fraction of ammonia is varied from 20 to 70 %. Methane flames are also tested as benchmark case. Flames are imaged using CCD camera fitted with bandpass filters. The binarized Abel-deconvoluted ∗ and ∗ chemiluminescence images are analysed to classify different flame shape transitions. In the non-premixed coaxial swirl combustor, it is observed that ammonia-hydrogen-nitrogen/air flame with 70 % ammonia behaved similar to methane which is in-line with past studies. The blowout limits and time-averaged flame topological transitions as swirl number was systematically varied were also similar. However, 70 % ammonia blend produced compact flames than that of methane. Also, the lift-off height was shorter. As the ammonia fraction decreases (accompanied by consequent increase in hydrogen fraction in the fuel) the blowout limits increase indicating that a stronger swirling strength of coaxial jet is required to blowout ammonia-lean (or hydrogen-rich) fuel. The flame transition zones also widen. The flames become more compact. All in all, ammonia-hydrogen-nitrogen flames with less than 60 % ammonia fraction behave differently when compared to 70 % ammonia fraction fuel and methane. Lastly, a Reynolds number defined based on velocity characterized by strength of coflow swirl jet is shown to vary linearly with fuel Reynolds number for all the fuels. Finally, an expression involving this Reynolds number is proposed as blowout criteria for ammonia-hydrogen-nitrogen flames within the ammonia fractions tested in the present study.
{"title":"Blowout and stability limits of ammonia-hydrogen-nitrogen/air flames in non-premixed coaxial swirl combustor with varying ammonia fraction","authors":"Rajneesh Yadav, R. Santhosh","doi":"10.1016/j.joei.2024.101928","DOIUrl":"10.1016/j.joei.2024.101928","url":null,"abstract":"<div><div>The present experimental investigation concerns identification of stable flame regimes and blowout limits of ammonia-hydrogen-nitrogen flames in confined coaxial swirling jet configuration with a confinement ratio (<span><math><mrow><mi>C</mi><mi>R</mi></mrow></math></span>) of 1.82. Volumetric fraction of ammonia is varied from 20 to 70 %. Methane flames are also tested as benchmark case. Flames are imaged using CCD camera fitted with bandpass filters. The binarized Abel-deconvoluted <span><math><mrow><mi>C</mi><mi>H</mi></mrow></math></span>∗ and <span><math><mrow><msub><mrow><mi>N</mi><mi>H</mi></mrow><mn>2</mn></msub></mrow></math></span>∗ chemiluminescence images are analysed to classify different flame shape transitions. In the non-premixed coaxial swirl combustor, it is observed that ammonia-hydrogen-nitrogen/air flame with 70 % ammonia behaved similar to methane which is in-line with past studies. The blowout limits and time-averaged flame topological transitions as swirl number was systematically varied were also similar. However, 70 % ammonia blend produced compact flames than that of methane. Also, the lift-off height was shorter. As the ammonia fraction decreases (accompanied by consequent increase in hydrogen fraction in the fuel) the blowout limits increase indicating that a stronger swirling strength of coaxial jet is required to blowout ammonia-lean (or hydrogen-rich) fuel. The flame transition zones also widen. The flames become more compact. All in all, ammonia-hydrogen-nitrogen flames with less than 60 % ammonia fraction behave differently when compared to 70 % ammonia fraction fuel and methane. Lastly, a Reynolds number defined based on velocity characterized by strength of coflow swirl jet is shown to vary linearly with fuel Reynolds number for all the fuels. Finally, an expression involving this Reynolds number is proposed as blowout criteria for ammonia-hydrogen-nitrogen flames within the ammonia fractions tested in the present study.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101928"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143178150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To efficiently utilize the oxygenated structures in lignite and obtain value-added oxygenated compounds, this study proposes a low carbon cascading utilization of Zhaotong lignite (ZT) through thermal dissolution and pyrolysis. The selectivity of ethanol (ET), tetrahydrofuran (THF) and ethyl acetate (EA) for oxygenated compounds in thermal dissolution, and the enrichment of thermal dissolution-pyrolysis on oil phases were investigated. The results show that sequential thermal dissolution is selective for different oxygenated compounds in ZT. ET shows selectivity for esters at 350 °C-2 MPa and for phenols at 350 °C-6 MPa. THF and EA are selective for naphthols and esters at 350 °C-6 MPa, respectively. Compared with the single process of thermal dissolution or pyrolysis, thermal dissolution-pyrolysis can significantly increase the oil phases yield with high value-added, in which ET, THF and EA increase the oil phase yields by 24.81 wt%, 13.66 wt% and 7.90 wt%, respectively. In particular, 59.15 wt% of the oxygen is distributed in light oil, and 9.79 % phenols as well as 1.56 % esters are enriched into light oil during thermal dissolution-pyrolysis process of ET. High value-added oxygenated compounds can be selectively enriched by appropriate solvents, at the same time, the quality of pyrolysis tar can be improved and the carbon emissions could be reduced.
{"title":"Study on enrichment of value-added oxygenated compounds from lignite by a low carbon cascading utilization","authors":"Meilu Hao , Peng Liang , Miaomiao Tian , Songze Li , Yue Gao , Yaqing Zhang , Xizhuang Qin , Wenrui Zhang , Tiantian Jiao","doi":"10.1016/j.joei.2024.101930","DOIUrl":"10.1016/j.joei.2024.101930","url":null,"abstract":"<div><div>To efficiently utilize the oxygenated structures in lignite and obtain value-added oxygenated compounds, this study proposes a low carbon cascading utilization of Zhaotong lignite (ZT) through thermal dissolution and pyrolysis. The selectivity of ethanol (ET), tetrahydrofuran (THF) and ethyl acetate (EA) for oxygenated compounds in thermal dissolution, and the enrichment of thermal dissolution-pyrolysis on oil phases were investigated. The results show that sequential thermal dissolution is selective for different oxygenated compounds in ZT. ET shows selectivity for esters at 350 °C-2 MPa and for phenols at 350 °C-6 MPa. THF and EA are selective for naphthols and esters at 350 °C-6 MPa, respectively. Compared with the single process of thermal dissolution or pyrolysis, thermal dissolution-pyrolysis can significantly increase the oil phases yield with high value-added, in which ET, THF and EA increase the oil phase yields by 24.81 wt%, 13.66 wt% and 7.90 wt%, respectively. In particular, 59.15 wt% of the oxygen is distributed in light oil, and 9.79 % phenols as well as 1.56 % esters are enriched into light oil during thermal dissolution-pyrolysis process of ET. High value-added oxygenated compounds can be selectively enriched by appropriate solvents, at the same time, the quality of pyrolysis tar can be improved and the carbon emissions could be reduced.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101930"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101938
Huabing Wen, Juntao Li, Jingrui Li, Changchun Xu
Investigating the intake-premixed ammonia engine reveals that it emits a significant amount of N2O and unburned NH3, which contradicts ammonia fuel's ability to reduce engine emissions and satisfy ever-tougher pollution regulations. To address these issues, a study utilizing CONVERGE software was conducted, and the effects of raising the intake air temperature and igniting near the Top Dead Center were examined. This study is based on the ammonia energy fraction (30%–80 %), intake air temperature (420K–480K), and O2 ratio (80%–100 % of original). As the NH3 energy fraction increases, the engine's combustion and emission performance significantly declines at an intake air temperature of 420 K. The effect of intake air temperature and O2 ratio on engine performance at 70 % ammonia energy fraction was then investigated. When the intake air temperature increases from 420K to 480K, the engine's combustion performance is greatly improved, but the NOx emissions increase from 3.17g/kWh to 7.09g/kWh. Lower O2 ratios are more effective in reducing NOx emissions and have less impact on engine performance at higher intake temperatures. Under the conditions of 70 % ammonia energy fraction, 480K intake air temperature, and 80 % of the original O2 ratio, the indicated thermal efficiency of this engine can reach 52 %, N2O and NH3 emissions can be ignored, and NOx emissions are 2.01g/kWh. At this load, an efficient combustion and low-emission operating scheme is provided for the intake-premixed ammonia engine.
{"title":"Effect of intake air conditions on combustion and emission performance of ammonia-diesel dual fuel engine","authors":"Huabing Wen, Juntao Li, Jingrui Li, Changchun Xu","doi":"10.1016/j.joei.2024.101938","DOIUrl":"10.1016/j.joei.2024.101938","url":null,"abstract":"<div><div>Investigating the intake-premixed ammonia engine reveals that it emits a significant amount of N<sub>2</sub>O and unburned NH<sub>3</sub>, which contradicts ammonia fuel's ability to reduce engine emissions and satisfy ever-tougher pollution regulations. To address these issues, a study utilizing CONVERGE software was conducted, and the effects of raising the intake air temperature and igniting near the Top Dead Center were examined. This study is based on the ammonia energy fraction (30%–80 %), intake air temperature (420K–480K), and O<sub>2</sub> ratio (80%–100 % of original). As the NH<sub>3</sub> energy fraction increases, the engine's combustion and emission performance significantly declines at an intake air temperature of 420 K. The effect of intake air temperature and O<sub>2</sub> ratio on engine performance at 70 % ammonia energy fraction was then investigated. When the intake air temperature increases from 420K to 480K, the engine's combustion performance is greatly improved, but the NOx emissions increase from 3.17g/kWh to 7.09g/kWh. Lower O<sub>2</sub> ratios are more effective in reducing NOx emissions and have less impact on engine performance at higher intake temperatures. Under the conditions of 70 % ammonia energy fraction, 480K intake air temperature, and 80 % of the original O<sub>2</sub> ratio, the indicated thermal efficiency of this engine can reach 52 %, N<sub>2</sub>O and NH<sub>3</sub> emissions can be ignored, and NOx emissions are 2.01g/kWh. At this load, an efficient combustion and low-emission operating scheme is provided for the intake-premixed ammonia engine.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101938"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101924
Yangyi Wu , Zhixiong Huang , Haifeng Liu , Zunqing Zheng , Xiaoteng Zhang , Chao Jin , Zhao Zhang , Mingfa Yao
Methanol, as a carbon-neutral resource, exhibits significant potential in the automotive sector, but its fuel characteristics are not easily compression ignited. In this experimental study, various strategies such as the preheating of the intake charge, augmentation of the compression ratio, and the introduction of 2-ethylhexyl nitrate (EHN) as an additive were implemented to enhance the combustion stability of pure methanol. In this study, an investigation was conducted on the combustion, fuel economy, and emission characteristics of pure methanol in a heavy-duty diesel engine. The experimental results revealed that the compression ratio of 21.5:1 had a more significant effect in reducing the ignition delay and combustion duration than the addition of 7 % EHN. Further, the compression ratio of 21.5:1 also improved brake thermal efficiency (BTE) by 4 %–11.9 %. In terms of emissions, with the addition of EHN in methanol under the lower compression ratio, NO and methanol emissions were higher. The peak particulate concentration and size of methanol gradually increased with load increasing. The incorporation of EHN resulted in an elevation in both the concentration and size, but still lower than those of diesel fuel. Based on the synergistic optimization of compression ratio and EHN addition ratio, the intake temperature required for achieving stable combustion was reduced, from 290 °C down to 70 °C, which was basically equivalent to 50 °C for diesel. The peak BTE of 30.19 % was achieved under the compression ratio of 21.5:1 and with the addition of 3 % EHN. This represented an 8.29 % improvement compared to the BTE of diesel fuel at the speed of 1144 rpm and the BMEP of 0.22 MPa. Thus, the pure methanol compression-ignition engine can reach the higher-efficiency, clean, and stable operation based on higher compression ratio (21.5:1) and low-ratio EHN addition (3 %), with a relatively normal intake temperature (70 °C).
{"title":"Conventional and unconventional gas emissions and particle matter emissions of methanol CI engine with different EHN addition and compression ratios","authors":"Yangyi Wu , Zhixiong Huang , Haifeng Liu , Zunqing Zheng , Xiaoteng Zhang , Chao Jin , Zhao Zhang , Mingfa Yao","doi":"10.1016/j.joei.2024.101924","DOIUrl":"10.1016/j.joei.2024.101924","url":null,"abstract":"<div><div>Methanol, as a carbon-neutral resource, exhibits significant potential in the automotive sector, but its fuel characteristics are not easily compression ignited. In this experimental study, various strategies such as the preheating of the intake charge, augmentation of the compression ratio, and the introduction of 2-ethylhexyl nitrate (EHN) as an additive were implemented to enhance the combustion stability of pure methanol. In this study, an investigation was conducted on the combustion, fuel economy, and emission characteristics of pure methanol in a heavy-duty diesel engine. The experimental results revealed that the compression ratio of 21.5:1 had a more significant effect in reducing the ignition delay and combustion duration than the addition of 7 % EHN. Further, the compression ratio of 21.5:1 also improved brake thermal efficiency (BTE) by 4 %–11.9 %. In terms of emissions, with the addition of EHN in methanol under the lower compression ratio, NO and methanol emissions were higher. The peak particulate concentration and size of methanol gradually increased with load increasing. The incorporation of EHN resulted in an elevation in both the concentration and size, but still lower than those of diesel fuel. Based on the synergistic optimization of compression ratio and EHN addition ratio, the intake temperature required for achieving stable combustion was reduced, from 290 °C down to 70 °C, which was basically equivalent to 50 °C for diesel. The peak BTE of 30.19 % was achieved under the compression ratio of 21.5:1 and with the addition of 3 % EHN. This represented an 8.29 % improvement compared to the BTE of diesel fuel at the speed of 1144 rpm and the BMEP of 0.22 MPa. Thus, the pure methanol compression-ignition engine can reach the higher-efficiency, clean, and stable operation based on higher compression ratio (21.5:1) and low-ratio EHN addition (3 %), with a relatively normal intake temperature (70 °C).</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101924"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-02-01DOI: 10.1016/j.joei.2024.101937
Runmin Wu , Xudong Song , Wenju Zhang , Juntao Wei , Jiaofei Wang , Peng Lv , Guangsuo Yu
Flame-wall collisions are common in industrial and household applications. Therefore, it is very important to carry out detailed research of flame structure and soot generation during flame-wall impingement. In this study, the reaction characteristics and soot distribution of impinging wall flames at different equivalence ratios (λ) and impact heights (L) were studied by means of spectral diagnosis and CFD simulation. The results noted that the increase of λ causes the OH∗ peak intensities and soot concentration to rise and then decrease, reaching a maximum value at λ = 0.5. With the increase of λ, the amount of precursor polycyclic aromatic hydrocarbons (A1-A4) decreased while the soot particles growth rate increased. When λ > 0.5, the soot oxidation is faster than the soot generation, and the soot is gradually oxidized, so that the soot concentration is the highest when λ = 0.5. With the increase of L, the jet flame fully develops before the impact plate, and the flame brightness gradually increases. The increase of the L leads to a weakening of the methane-oxygen mixing and at the same time to a gradual loss of the kinetic energy of the flame along the impingement plate, which further causes an increase of the temperature and the soot content in the region where the flame jet is fully developed.
{"title":"Effect of flame-wall impingement on heat transfer characteristics and soot migration in methane inverse diffusion flames","authors":"Runmin Wu , Xudong Song , Wenju Zhang , Juntao Wei , Jiaofei Wang , Peng Lv , Guangsuo Yu","doi":"10.1016/j.joei.2024.101937","DOIUrl":"10.1016/j.joei.2024.101937","url":null,"abstract":"<div><div>Flame-wall collisions are common in industrial and household applications. Therefore, it is very important to carry out detailed research of flame structure and soot generation during flame-wall impingement. In this study, the reaction characteristics and soot distribution of impinging wall flames at different equivalence ratios (λ) and impact heights (L) were studied by means of spectral diagnosis and CFD simulation. The results noted that the increase of λ causes the OH∗ peak intensities and soot concentration to rise and then decrease, reaching a maximum value at λ = 0.5. With the increase of λ, the amount of precursor polycyclic aromatic hydrocarbons (A1-A4) decreased while the soot particles growth rate increased. When λ > 0.5, the soot oxidation is faster than the soot generation, and the soot is gradually oxidized, so that the soot concentration is the highest when λ = 0.5. With the increase of L, the jet flame fully develops before the impact plate, and the flame brightness gradually increases. The increase of the L leads to a weakening of the methane-oxygen mixing and at the same time to a gradual loss of the kinetic energy of the flame along the impingement plate, which further causes an increase of the temperature and the soot content in the region where the flame jet is fully developed.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"118 ","pages":"Article 101937"},"PeriodicalIF":5.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176610","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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