Pub Date : 2025-11-24DOI: 10.1016/j.joei.2025.102387
Lei Huang , Lingxue Kong , Guanghui Zhang , Tiantian Ma , Xiaojun Xuan , Jin Bai , Wen Li
This study elucidates the dual mechanisms governing PM10 formation during high-sodium coal gasification through integrated experimental and modeling approaches. Utilizing a flat-flame burner reactor at 1200–1400 °C, we systematically investigated temperature-dependent particle morphology evolution and chemical speciation. The bimodal particle size distribution revealed distinct formation pathways: ultrafine particles (<0.154 μm) predominantly originated from vaporization-nucleation of alkali/refractory elements, while larger particulates (0.154–10 μm) stemmed from mineral fragmentation. Elevated temperatures (Δ200 °C) enhanced Na/Si/Ca vaporization by 7.2/165/243-fold respectively, correlating with 178 % PM0.05 yield increase. Notably, H2-mediated reduction dominated Si/Ca/Mg release (53–68 %), contrasting with CO-driven Fe volatilization (66 %). The developed multiscale model incorporating char conversion kinetics, mineral thermodynamics, and aerosol dynamics successfully predicted particulate yields and particle size distribution transitions. These findings provide critical insights for optimizing gasifier operations to mitigate PM emissions in high-sodium coal utilization.
{"title":"Deciphering PM10 formation in high-sodium coal gasification: Synergistic effects of mineral vaporization and fragmentation","authors":"Lei Huang , Lingxue Kong , Guanghui Zhang , Tiantian Ma , Xiaojun Xuan , Jin Bai , Wen Li","doi":"10.1016/j.joei.2025.102387","DOIUrl":"10.1016/j.joei.2025.102387","url":null,"abstract":"<div><div>This study elucidates the dual mechanisms governing PM<sub>10</sub> formation during high-sodium coal gasification through integrated experimental and modeling approaches. Utilizing a flat-flame burner reactor at 1200–1400 °C, we systematically investigated temperature-dependent particle morphology evolution and chemical speciation. The bimodal particle size distribution revealed distinct formation pathways: ultrafine particles (<0.154 μm) predominantly originated from vaporization-nucleation of alkali/refractory elements, while larger particulates (0.154–10 μm) stemmed from mineral fragmentation. Elevated temperatures (Δ200 °C) enhanced Na/Si/Ca vaporization by 7.2/165/243-fold respectively, correlating with 178 % PM<sub>0.05</sub> yield increase. Notably, H<sub>2</sub>-mediated reduction dominated Si/Ca/Mg release (53–68 %), contrasting with CO-driven Fe volatilization (66 %). The developed multiscale model incorporating char conversion kinetics, mineral thermodynamics, and aerosol dynamics successfully predicted particulate yields and particle size distribution transitions. These findings provide critical insights for optimizing gasifier operations to mitigate PM emissions in high-sodium coal utilization.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102387"},"PeriodicalIF":6.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614516","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}
In this study, hydrothermal liquefaction (HTL) of rice straw (RS) an abundant agricultural waste was carried out to produce bio-oil. Silica (SiO2)-rich ash derived from RS was used as a catalyst. Different reaction parameters such as reaction temperatures (230–270 °C), residence times (15–45 min), catalytic dosage (5–15 wt%) and different solvents such as water (H2O), Ethanol (EtOH), water-ethanol (H2O-EtOH), water-methanol (H2O-MeOH), and water-isopropyl alcohol (H2O-IPA) solvent mixtures were employed. In non-catalytic HTL, the highest bio-oil yield (52.5 wt%) was obtained using an H2O-EtOH solvent mixture compared to H2O (14.75 wt%), EtOH (25.2 wt%), H2O-MeOH (45.7 wt%), and H2O-IPA (51.2 wt%) at temperature 250 °C for 30 min of reaction time. Using a SiO2-rich ash catalyst further improved the bio-oil yield to 59.16 wt% at 250 °C for 30 min under the H2O-EtOH solvent system. Catalytic HTL bio-oil showed a high content of phenolics (24.12 %), ketones/aldehydes (22.12 %), and hydrocarbons (18.61 %). The hydrogenation reaction was promoted in the presence of catalyst and the higher phenolic and hydrocarbon content was found in the catalytic bio-oil. The bio-oil obtained under catalytic conditions exhibited lower oxygen content (30.6 wt%) and a higher heating value (26.61 MJ/kg) compared to bio-oil obtained under non-catalytic reactions. This study highlights the potential of SiO2 rich ash catalysts from RS biomass for producing quality bio-oil.
{"title":"Rice straw derived silica rich ash catalyst for efficient hydrothermal liquefaction of rice straw to value added chemicals","authors":"Bijoy Biswas , Mridusmita Dutta , Shivani Thakur , Yogalakshmi Kadapakkam Nandabalan , Sandeep Kumar , Rawel Singh","doi":"10.1016/j.joei.2025.102393","DOIUrl":"10.1016/j.joei.2025.102393","url":null,"abstract":"<div><div>In this study, hydrothermal liquefaction (HTL) of rice straw (RS) an abundant agricultural waste was carried out to produce bio-oil. Silica (SiO<sub>2</sub>)-rich ash derived from RS was used as a catalyst. Different reaction parameters such as reaction temperatures (230–270 °C), residence times (15–45 min), catalytic dosage (5–15 wt%) and different solvents such as water (H<sub>2</sub>O), Ethanol (EtOH), water-ethanol (H<sub>2</sub>O-EtOH), water-methanol (H<sub>2</sub>O-MeOH), and water-isopropyl alcohol (H<sub>2</sub>O-IPA) solvent mixtures were employed. In non-catalytic HTL, the highest bio-oil yield (52.5 wt%) was obtained using an H<sub>2</sub>O-EtOH solvent mixture compared to H<sub>2</sub>O (14.75 wt%), EtOH (25.2 wt%), H<sub>2</sub>O-MeOH (45.7 wt%), and H<sub>2</sub>O-IPA (51.2 wt%) at temperature 250 °C for 30 min of reaction time. Using a SiO<sub>2</sub>-rich ash catalyst further improved the bio-oil yield to 59.16 wt% at 250 °C for 30 min under the H<sub>2</sub>O-EtOH solvent system. Catalytic HTL bio-oil showed a high content of phenolics (24.12 %), ketones/aldehydes (22.12 %), and hydrocarbons (18.61 %). The hydrogenation reaction was promoted in the presence of catalyst and the higher phenolic and hydrocarbon content was found in the catalytic bio-oil. The bio-oil obtained under catalytic conditions exhibited lower oxygen content (30.6 wt%) and a higher heating value (26.61 MJ/kg) compared to bio-oil obtained under non-catalytic reactions. This study highlights the potential of SiO<sub>2</sub> rich ash catalysts from RS biomass for producing quality bio-oil.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102393"},"PeriodicalIF":6.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614628","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 : 2025-11-24DOI: 10.1016/j.joei.2025.102391
Qingyang Liu, Haoye Liu, Tianyou Wang
In this study, the effect of nitrogen-containing functional groups introduced by nitrogen-containing species on the oxidation characteristics of polycyclic aromatic hydrocarbons (PAHs) was explored with reactive force field molecule dynamics (ReaxFF MD) simulations and quantum chemical calculations. The results of oxidation degrees indicate nitrogen-containing functional groups promote the oxidation of PAHs to varying extents. The evolution of the number of aromatic rings further demonstrates that nitrogen-containing functional groups accelerate oxidative cleavage of aromatic rings into chain molecules more effectively than isoelectronic hydrocarbon functional groups. Reaction mechanism analysis indicates that nitrogen-containing functional groups have higher reactivity, making them more likely to react with O2 and active radicals (O and OH radicals). Energy barrier analysis shows that the energy barrier for the H-abstraction by O2 involving the amino group is lower than that of isoelectronic hydrocarbon functional groups. Meanwhile, the amino group lowers the energy barriers for both H-abstraction and O-addition reactions on the aromatic ring, greatly reducing the difficulty for active radicals to attack the aromatic ring. Overall, nitrogen-containing functional groups affect the oxidation characteristics of PAHs through two main effects: (1) Nitrogen-containing functional groups exhibit high reactivity, making them prone to rapid oxidation reactions with O2 and active radicals; (2) Nitrogen-containing functional groups reduce the energy barriers of key oxidation reactions involving the aromatic ring, or maintain it at a lower level, facilitating the attack of active radicals on the aromatic rings. The synergistic effect of these two factors makes PAHs with nitrogen-containing functional groups more susceptible to oxidation.
{"title":"Effect of nitrogen-containing functional groups on the oxidation characteristics of polycyclic aromatic hydrocarbons: A combined study of ReaxFF MD simulations and quantum chemical calculations","authors":"Qingyang Liu, Haoye Liu, Tianyou Wang","doi":"10.1016/j.joei.2025.102391","DOIUrl":"10.1016/j.joei.2025.102391","url":null,"abstract":"<div><div>In this study, the effect of nitrogen-containing functional groups introduced by nitrogen-containing species on the oxidation characteristics of polycyclic aromatic hydrocarbons (PAHs) was explored with reactive force field molecule dynamics (ReaxFF MD) simulations and quantum chemical calculations. The results of oxidation degrees indicate nitrogen-containing functional groups promote the oxidation of PAHs to varying extents. The evolution of the number of aromatic rings further demonstrates that nitrogen-containing functional groups accelerate oxidative cleavage of aromatic rings into chain molecules more effectively than isoelectronic hydrocarbon functional groups. Reaction mechanism analysis indicates that nitrogen-containing functional groups have higher reactivity, making them more likely to react with O<sub>2</sub> and active radicals (O and OH radicals). Energy barrier analysis shows that the energy barrier for the H-abstraction by O<sub>2</sub> involving the amino group is lower than that of isoelectronic hydrocarbon functional groups. Meanwhile, the amino group lowers the energy barriers for both H-abstraction and O-addition reactions on the aromatic ring, greatly reducing the difficulty for active radicals to attack the aromatic ring. Overall, nitrogen-containing functional groups affect the oxidation characteristics of PAHs through two main effects: (1) Nitrogen-containing functional groups exhibit high reactivity, making them prone to rapid oxidation reactions with O<sub>2</sub> and active radicals; (2) Nitrogen-containing functional groups reduce the energy barriers of key oxidation reactions involving the aromatic ring, or maintain it at a lower level, facilitating the attack of active radicals on the aromatic rings. The synergistic effect of these two factors makes PAHs with nitrogen-containing functional groups more susceptible to oxidation.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102391"},"PeriodicalIF":6.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614596","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 : 2025-11-24DOI: 10.1016/j.joei.2025.102398
Yongfeng Liu , Yuanchao Shao , Jiahao Zhang , Shengzhuo Yao , Zhandong Wang , Bin Guan , Zijian Zhou , Hua Sun
To investigate the oxidation of n-heptane (C7H16) under CO2/O2 atmosphere, an oxidation model (COO model) is developed using quantum chemistry and Synchrotron Vacuum Ultraviolet Photoionization Mass Spectrometry (SVUV-PIMS) technology. Electrostatic potential (ESP) and Fukui-function analyses identify reaction sites for CO2 with OH, H, CH3, and CH2 radicals and reveal reaction pathways. Oxidation experiment of C7H16 under CO2/O2 atmosphere is conducted using a jet-stirred reactor (JSR) developed with SVUV-PIMS, and the oxidation products at an equivalence ratio of 2/3, temperature range of 700–1000 K, and 1 atm are quantitatively analyzed. The results show that the COO model is applicable for the oxidation of C7H16 under CO2/O2 atmosphere, with a maximum error of 8.9 % in the oxidation of C7H16. A total of 29 oxidation products are identified, with C2H4 having the highest peak molar fraction of 1.7 × 10−2. The Negative Temperature Coefficient (NTC) region for C7H16 oxidation under CO2/O2 atmosphere is delayed by 125 K compared to O2, with the maximum reaction rate occurring at 750 K. CO2 primarily inhibits the formation of OH and other radicals before 800 K and also reacts minimally with radicals such as OH, H, CH3, and CH2, thereby delaying the NTC temperature region of C7H16. In the reaction pathways CO2+H→CO + OH and CO2+OH→CO + HO2, the highest intermediate energies are 1.75 kcal/mol higher and 73.17 kcal/mol lower than the reactants, respectively. In the pathways CO2+CH3→CO + H2O + CH and CO2+CH2→CH2O + CO, the highest intermediate energies are 147.65 kcal/mol higher and 64.13 kcal/mol lower than the reactants.
{"title":"Oxidation of n-heptane under CO2/O2: Quantum chemistry and SVUV-PIMS experiment","authors":"Yongfeng Liu , Yuanchao Shao , Jiahao Zhang , Shengzhuo Yao , Zhandong Wang , Bin Guan , Zijian Zhou , Hua Sun","doi":"10.1016/j.joei.2025.102398","DOIUrl":"10.1016/j.joei.2025.102398","url":null,"abstract":"<div><div>To investigate the oxidation of n-heptane (C<sub>7</sub>H<sub>16</sub>) under CO<sub>2</sub>/O<sub>2</sub> atmosphere, an oxidation model (COO model) is developed using quantum chemistry and Synchrotron Vacuum Ultraviolet Photoionization Mass Spectrometry (SVUV-PIMS) technology. Electrostatic potential (ESP) and Fukui-function analyses identify reaction sites for CO<sub>2</sub> with OH, H, CH<sub>3</sub>, and CH<sub>2</sub> radicals and reveal reaction pathways. Oxidation experiment of C<sub>7</sub>H<sub>16</sub> under CO<sub>2</sub>/O<sub>2</sub> atmosphere is conducted using a jet-stirred reactor (JSR) developed with SVUV-PIMS, and the oxidation products at an equivalence ratio of 2/3, temperature range of 700–1000 K, and 1 atm are quantitatively analyzed. The results show that the COO model is applicable for the oxidation of C<sub>7</sub>H<sub>16</sub> under CO<sub>2</sub>/O<sub>2</sub> atmosphere, with a maximum error of 8.9 % in the oxidation of C<sub>7</sub>H<sub>16</sub>. A total of 29 oxidation products are identified, with C<sub>2</sub>H<sub>4</sub> having the highest peak molar fraction of 1.7 × 10<sup>−2</sup>. The Negative Temperature Coefficient (NTC) region for C<sub>7</sub>H<sub>16</sub> oxidation under CO<sub>2</sub>/O<sub>2</sub> atmosphere is delayed by 125 K compared to O<sub>2</sub>, with the maximum reaction rate occurring at 750 K. CO<sub>2</sub> primarily inhibits the formation of OH and other radicals before 800 K and also reacts minimally with radicals such as OH, H, CH<sub>3</sub>, and CH<sub>2</sub>, thereby delaying the NTC temperature region of C<sub>7</sub>H<sub>16</sub>. In the reaction pathways CO<sub>2</sub>+H→CO + OH and CO<sub>2</sub>+OH→CO + HO<sub>2</sub>, the highest intermediate energies are 1.75 kcal/mol higher and 73.17 kcal/mol lower than the reactants, respectively. In the pathways CO<sub>2</sub>+CH<sub>3</sub>→CO + H<sub>2</sub>O + CH and CO<sub>2</sub>+CH<sub>2</sub>→CH<sub>2</sub>O + CO, the highest intermediate energies are 147.65 kcal/mol higher and 64.13 kcal/mol lower than the reactants.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102398"},"PeriodicalIF":6.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614633","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}
This study investigates the CO and NO emission characteristics of laminar premixed CH4-NH3 jet impinging flames under various conditions. Effects of equivalence ratio (φ), ammonia fraction in the fuel blends (ηNH3) and Reynolds number (Re) on pollutant formation are analyzed comprehensively under different impingement conditions. Results show that CO emissions generally increase with φ due to oxidizer deficiency, with their variations mainly controlled by wall-cooling effects on CO oxidation in lean flames. In contrast, NO emissions exhibit a V-shaped dependence on φ, with higher levels in fuel-rich flames. Additional air entrainment at fuel-rich conditions promotes NH3 oxidation and suppresses DeNOx reactions, leading to the elevated NO levels. Meanwhile, strong wall cooling at small nozzle-to-wall distance (H) favors the HNO pathway, further increasing NO emissions near the wall. When increasing ηNH3, CO emissions decrease steadily owing to reduced carbon input. However, the extent of reduction depends on the impingement condition, showing a moderate decrease at large H and a more pronounced decline at small H. NO emissions initially rise with ηNH3 up to about 60 %, driven by enhanced NH/NH2 radical formation and thermal-NO production, and then decrease at higher ηNH3 as reduced reactivity slows NH3 oxidation and strengthens DeNOx reactions. Besides, CO emissions decrease with increasing Re at small H because stronger impingement suppresses premixed combustion and CO generation, while they increase at large H due to enhanced CO formation resulting from the coupling effects of the reduced wall cooling, extended post-flame zones and limited ambient oxidizer. NO emissions rise monotonically with Re, driven by higher flame temperatures, enhanced NH3 consumption and inhibited NO destruction. Overall, flame impingement dominates the overall CO/NO emission levels, while φ, ηNH3 and Re modulate detailed emission behaviors through coupled effects of wall cooling and air entrainment.
{"title":"Experimental investigation on emission characteristics of laminar premixed CH4-NH3 jet impinging flames across a wide range of conditions","authors":"Zhilong Wei, Guanglong Huang, Guangyu Zeng, Haisheng Zhen","doi":"10.1016/j.joei.2025.102392","DOIUrl":"10.1016/j.joei.2025.102392","url":null,"abstract":"<div><div>This study investigates the CO and NO emission characteristics of laminar premixed CH<sub>4</sub>-NH<sub>3</sub> jet impinging flames under various conditions. Effects of equivalence ratio (<em>φ</em>), ammonia fraction in the fuel blends (<em>η</em><sub>NH3</sub>) and Reynolds number (<em>Re</em>) on pollutant formation are analyzed comprehensively under different impingement conditions. Results show that CO emissions generally increase with <em>φ</em> due to oxidizer deficiency, with their variations mainly controlled by wall-cooling effects on CO oxidation in lean flames. In contrast, NO emissions exhibit a V-shaped dependence on <em>φ</em>, with higher levels in fuel-rich flames. Additional air entrainment at fuel-rich conditions promotes NH<sub>3</sub> oxidation and suppresses DeNOx reactions, leading to the elevated NO levels. Meanwhile, strong wall cooling at small nozzle-to-wall distance (<em>H</em>) favors the HNO pathway, further increasing NO emissions near the wall. When increasing <em>η</em><sub>NH3</sub>, CO emissions decrease steadily owing to reduced carbon input. However, the extent of reduction depends on the impingement condition, showing a moderate decrease at large <em>H</em> and a more pronounced decline at small <em>H</em>. NO emissions initially rise with <em>η</em><sub>NH3</sub> up to about 60 %, driven by enhanced NH/NH<sub>2</sub> radical formation and thermal-NO production, and then decrease at higher <em>η</em><sub>NH3</sub> as reduced reactivity slows NH<sub>3</sub> oxidation and strengthens DeNOx reactions. Besides, CO emissions decrease with increasing <em>Re</em> at small <em>H</em> because stronger impingement suppresses premixed combustion and CO generation, while they increase at large <em>H</em> due to enhanced CO formation resulting from the coupling effects of the reduced wall cooling, extended post-flame zones and limited ambient oxidizer. NO emissions rise monotonically with <em>Re</em>, driven by higher flame temperatures, enhanced NH<sub>3</sub> consumption and inhibited NO destruction. Overall, flame impingement dominates the overall CO/NO emission levels, while <em>φ</em>, <em>η</em><sub>NH3</sub> and <em>Re</em> modulate detailed emission behaviors through coupled effects of wall cooling and air entrainment.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102392"},"PeriodicalIF":6.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614629","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 : 2025-11-24DOI: 10.1016/j.joei.2025.102397
Weiqi Luo , Wenjun Ding , Jianguo Du , Yu Wang
Staged burners have been widely used in industry to reduce NOx emissions. However, the overall effectiveness depends on its operation conditions. Traditional monitoring methods of NOx and CO emissions, such as gas analyzers, are too slow and impractical for real-time optimization. This study investigates flame chemiluminescence as a practical, non-intrusive indicator for combustion control. A staged-burner experimental platform was developed allowing independent control of fuel and air supply. Pollutant concentrations (CO, NOx) and flame radiative emission spectra (OH*, CH*, C2*) were measured under varied excess air ratios. Results reveal that CH*/OH* ratios decrease linearly, while C2*/CH* and C2*/OH* exhibit unimodal behaviors with increasing air ratio. These spectral signatures strongly correlate with emission levels, enabling indirect yet reliable indicators for low-emission operation. Spatially resolved measurements with ICCD imaging further validate optimal detection zones and filter bandwidth effects, ensuring applicability with cost-effective sensors. Overall, this work demonstrates the feasibility of chemiluminescence-guided closed-loop control, offering a pathway toward cleaner and more efficient industry burners.
{"title":"Chemiluminescence-based control for low-emission combustion in a rich-lean staged burner","authors":"Weiqi Luo , Wenjun Ding , Jianguo Du , Yu Wang","doi":"10.1016/j.joei.2025.102397","DOIUrl":"10.1016/j.joei.2025.102397","url":null,"abstract":"<div><div>Staged burners have been widely used in industry to reduce NO<sub>x</sub> emissions. However, the overall effectiveness depends on its operation conditions. Traditional monitoring methods of NO<sub>x</sub> and CO emissions, such as gas analyzers, are too slow and impractical for real-time optimization. This study investigates flame chemiluminescence as a practical, non-intrusive indicator for combustion control. A staged-burner experimental platform was developed allowing independent control of fuel and air supply. Pollutant concentrations (CO, NO<sub>x</sub>) and flame radiative emission spectra (OH*, CH*, C<sub>2</sub>*) were measured under varied excess air ratios. Results reveal that CH*/OH* ratios decrease linearly, while C<sub>2</sub>*/CH* and C<sub>2</sub>*/OH* exhibit unimodal behaviors with increasing air ratio. These spectral signatures strongly correlate with emission levels, enabling indirect yet reliable indicators for low-emission operation. Spatially resolved measurements with ICCD imaging further validate optimal detection zones and filter bandwidth effects, ensuring applicability with cost-effective sensors. Overall, this work demonstrates the feasibility of chemiluminescence-guided closed-loop control, offering a pathway toward cleaner and more efficient industry burners.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102397"},"PeriodicalIF":6.2,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145614517","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 : 2025-11-19DOI: 10.1016/j.joei.2025.102383
Liming Wang , Fangxi Xie , Linghai Han , Yanfeng Gong , Hanshi Qu , Zhe Zhao , Xiangyang Wang
Ammonia is a zero-carbon fuel with broad application prospects, yet it faces challenges such as difficulty in ignition and slow flame propagation speed. Active pre-chamber hydrogen jet ignition represents a highly promising technical approach to overcoming the combustion challenges of ammonia. In this experiment, the effects of pre-chamber hydrogen injection parameters on engine combustion, fuel economy, and emission characteristics were investigated. The results indicate that a hydrogen energy ratio (HER) around 6.6 % yields the most concentrated combustion, significantly increases the peak heat release rate, and shortens the combustion duration. The brake thermal efficiency (BTE) shows a non-monotonic relationship with HER, achieving its maximum value at HER = 6.6 %, which is 3.62 % higher than at HER = 1.8 %. Regarding emissions, increasing HER reduces unburned NH3 but increases NOx emissions. Excessively advanced or retarded hydrogen injection timing (HIT) delays the combustion phasing, reduces the indicated mean effective pressure (IMEP), and increases NH3 emissions. Combustion performance are optimal when HIT is between 75°CA BTDC and 100°CA BTDC. In comparison, HIP exhibits a minor influence on engine performance, with 1 MPa yielding superior performance in IMEP and BTE while maintaining the coefficient of variation of IMEP (COVIMEP) below 2.3 %. This work establishes optimized injection parameter ranges for active pre-chamber ammonia engines, providing critical insights for scaling up hydrogen-enhanced ammonia combustion systems.
{"title":"Research on performance improvement of ammonia engine based on optimization of active pre-chamber hydrogen injection strategy","authors":"Liming Wang , Fangxi Xie , Linghai Han , Yanfeng Gong , Hanshi Qu , Zhe Zhao , Xiangyang Wang","doi":"10.1016/j.joei.2025.102383","DOIUrl":"10.1016/j.joei.2025.102383","url":null,"abstract":"<div><div>Ammonia is a zero-carbon fuel with broad application prospects, yet it faces challenges such as difficulty in ignition and slow flame propagation speed. Active pre-chamber hydrogen jet ignition represents a highly promising technical approach to overcoming the combustion challenges of ammonia. In this experiment, the effects of pre-chamber hydrogen injection parameters on engine combustion, fuel economy, and emission characteristics were investigated. The results indicate that a hydrogen energy ratio (HER) around 6.6 % yields the most concentrated combustion, significantly increases the peak heat release rate, and shortens the combustion duration. The brake thermal efficiency (BTE) shows a non-monotonic relationship with HER, achieving its maximum value at HER = 6.6 %, which is 3.62 % higher than at HER = 1.8 %. Regarding emissions, increasing HER reduces unburned NH<sub>3</sub> but increases NO<sub>x</sub> emissions. Excessively advanced or retarded hydrogen injection timing (HIT) delays the combustion phasing, reduces the indicated mean effective pressure (IMEP), and increases NH<sub>3</sub> emissions. Combustion performance are optimal when HIT is between 75°CA BTDC and 100°CA BTDC. In comparison, HIP exhibits a minor influence on engine performance, with 1 MPa yielding superior performance in IMEP and BTE while maintaining the coefficient of variation of IMEP (COV<sub>IMEP</sub>) below 2.3 %. This work establishes optimized injection parameter ranges for active pre-chamber ammonia engines, providing critical insights for scaling up hydrogen-enhanced ammonia combustion systems.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102383"},"PeriodicalIF":6.2,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569225","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 : 2025-11-11DOI: 10.1016/j.joei.2025.102381
Peng Zhang , Guang-Hui Liu , Yao-Shun Wen , Yu-Hong Kang , Yang-Fan Yin , Sheng Li , Zhi-Xin Li , Zhi-Hao Ma
Morphology engineering plays a pivotal role in boosting catalytic performance over heterogeneous catalysis. However, although Y2O3 (a rare earth oxide) has been found to possess various morphologies, including nanoplate (NP), nanosphere (NS) and nanorod (NR), the lack of understanding of its catalytic mechanism still limits its further application. Herein, catalytic mechanism of Y2O3 morphologies in reverse water-gas shift (RWGS) reaction over Cu-based catalysts was systematically investigated. Although Y2O3 morphologies don't affect CO selectivity, it has a significant impact on CO2 conversion and stability. Systematic characterization reveals that Y2O3 morphologies not only can optimize the CO2 adsorption capacity and Cu nanoparticles size to enhance catalytic activity, but also can regulate the metal-support interaction to improve catalytic stability. The order of activity and stability of the Cu/Y2O3 catalysts from high to low is: Cu/NPY2O3 > Cu/NRY2O3 > Cu/NSY2O3. This work clarifies the morphological-performance relationship in rare earth oxide-Y2O3, providing a new approach for the design of high-performance Cu-based catalysts for RWGS reaction and promoting the application of morphology engineering in heterogeneous catalysis.
{"title":"Morphology-engineered Y2O3 nanostructures for boosting the RWGS reaction performance over Cu-based catalysts","authors":"Peng Zhang , Guang-Hui Liu , Yao-Shun Wen , Yu-Hong Kang , Yang-Fan Yin , Sheng Li , Zhi-Xin Li , Zhi-Hao Ma","doi":"10.1016/j.joei.2025.102381","DOIUrl":"10.1016/j.joei.2025.102381","url":null,"abstract":"<div><div>Morphology engineering plays a pivotal role in boosting catalytic performance over heterogeneous catalysis. However, although Y<sub>2</sub>O<sub>3</sub> (a rare earth oxide) has been found to possess various morphologies, including nanoplate (NP), nanosphere (NS) and nanorod (NR), the lack of understanding of its catalytic mechanism still limits its further application. Herein, catalytic mechanism of Y<sub>2</sub>O<sub>3</sub> morphologies in reverse water-gas shift (RWGS) reaction over Cu-based catalysts was systematically investigated. Although Y<sub>2</sub>O<sub>3</sub> morphologies don't affect CO selectivity, it has a significant impact on CO<sub>2</sub> conversion and stability. Systematic characterization reveals that Y<sub>2</sub>O<sub>3</sub> morphologies not only can optimize the CO<sub>2</sub> adsorption capacity and Cu nanoparticles size to enhance catalytic activity, but also can regulate the metal-support interaction to improve catalytic stability. The order of activity and stability of the Cu/Y<sub>2</sub>O<sub>3</sub> catalysts from high to low is: Cu/<sub>NP</sub>Y<sub>2</sub>O<sub>3</sub> > Cu/<sub>NR</sub>Y<sub>2</sub>O<sub>3</sub> > Cu/<sub>NS</sub>Y<sub>2</sub>O<sub>3</sub>. This work clarifies the morphological-performance relationship in rare earth oxide-Y<sub>2</sub>O<sub>3</sub>, providing a new approach for the design of high-performance Cu-based catalysts for RWGS reaction and promoting the application of morphology engineering in heterogeneous catalysis.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102381"},"PeriodicalIF":6.2,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145569224","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 : 2025-11-11DOI: 10.1016/j.joei.2025.102382
Jiuyi Zhang , Yinhu Kang , Haoran Wang , Wenxuan Zhou , Xiaomei Huang , Xiaofeng Lu , Jiayi Chang , Wenjin Lai
This article studies the promotion effect as well as the underlying physics of ozone (O3) addition on the ammonia (NH3) flammability. By the aid of chemical explosive mode analysis (CEMA) and diffusion index (DI), this study systematically elucidates the mechanisms through which O3 extends the extinction limits of NH3 counterflow diffusion flames. It shows that at the O3 substitution ratio θ = 0.4 (XO3 = 8.54 %), the extinction strain rate increases by 15.68-folds, and the maximum temperature is elevated by 16.9 % compared to the pure-air condition. O atoms produced via the O3 decomposition in the low-temperature zone trigger the subsequent exothermic chain-branching reactions, substantially elevating radical pool concentrations and augmenting reactivity across both the low- and high-temperature regions. The extension of flammability limit upon O3 addition is primarily due to the ozone chemistry, while the oxygen-enrichment effect is relatively less important. Moreover, CEMA diagnostics indicate that heat and N2 diffusions play distinct roles in the low-temperature ignition chemistry, which determines the local combustion mode transition from extinction (EXTC) to diffusion-assisted ignition (DIFF), a process fundamentally-significant to the extension of extinction limit. Diffusion and chemistry in the secondary heat release zone are rather insensitive to strain rate, exerting minimal influence on extinction. In contrast, the primary reaction zone exhibits a distinct modal sequence (exhaust→DIFF→EXTC) with increasing strain rate. Extinction eventually happens when the EXTC branch encroaches into the primary heat release peak, arising from flame inhibition induced by NH3 diffusion (DI(NH3)<0, α < −1), which surpasses the augmentation effect by heat conduction. In summary, O3 enhances the NH3 flammability by reshaping the low-temperature reaction pathways and intensity and altering the local combustion modes. The findings would be fundamentally meaningful to the development of efficient and reliable ammonia-fueled combustion systems in practical scenarios.
{"title":"Ozone-enhanced extinction limits of ammonia counterflow diffusion flames: Detections by chemical explosive mode analysis","authors":"Jiuyi Zhang , Yinhu Kang , Haoran Wang , Wenxuan Zhou , Xiaomei Huang , Xiaofeng Lu , Jiayi Chang , Wenjin Lai","doi":"10.1016/j.joei.2025.102382","DOIUrl":"10.1016/j.joei.2025.102382","url":null,"abstract":"<div><div>This article studies the promotion effect as well as the underlying physics of ozone (O<sub>3</sub>) addition on the ammonia (NH<sub>3</sub>) flammability. By the aid of chemical explosive mode analysis (CEMA) and diffusion index (DI), this study systematically elucidates the mechanisms through which O<sub>3</sub> extends the extinction limits of NH<sub>3</sub> counterflow diffusion flames. It shows that at the O<sub>3</sub> substitution ratio <em>θ</em> = 0.4 (<em>X</em><sub>O3</sub> = 8.54 %), the extinction strain rate increases by 15.68-folds, and the maximum temperature is elevated by 16.9 % compared to the pure-air condition. O atoms produced via the O<sub>3</sub> decomposition in the low-temperature zone trigger the subsequent exothermic chain-branching reactions, substantially elevating radical pool concentrations and augmenting reactivity across both the low- and high-temperature regions. The extension of flammability limit upon O<sub>3</sub> addition is primarily due to the ozone chemistry, while the oxygen-enrichment effect is relatively less important. Moreover, CEMA diagnostics indicate that heat and N<sub>2</sub> diffusions play distinct roles in the low-temperature ignition chemistry, which determines the local combustion mode transition from extinction (EXTC) to diffusion-assisted ignition (DIFF), a process fundamentally-significant to the extension of extinction limit. Diffusion and chemistry in the secondary heat release zone are rather insensitive to strain rate, exerting minimal influence on extinction. In contrast, the primary reaction zone exhibits a distinct modal sequence (exhaust→DIFF→EXTC) with increasing strain rate. Extinction eventually happens when the EXTC branch encroaches into the primary heat release peak, arising from flame inhibition induced by NH<sub>3</sub> diffusion (DI(NH<sub>3</sub>)<0, <em>α</em> < −1), which surpasses the augmentation effect by heat conduction. In summary, O<sub>3</sub> enhances the NH<sub>3</sub> flammability by reshaping the low-temperature reaction pathways and intensity and altering the local combustion modes. The findings would be fundamentally meaningful to the development of efficient and reliable ammonia-fueled combustion systems in practical scenarios.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102382"},"PeriodicalIF":6.2,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517264","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 : 2025-11-10DOI: 10.1016/j.joei.2025.102364
Yili Zhang , Xin Su , Hao Guo , Rihong Xiao , Xuebin Wang , Junying Zhang
Coal gasification slag (GS), a solid waste from the coal chemical industry, holds promise as an efficient and environmentally friendly adsorbent. This study selected four typical gasification slag samples and conducted mercury removal experiments at different reaction temperatures. The results showed that sample refined carbon (RC) was suitable for low-temperature mercury removal, achieving an efficiency of 90.91 %, while sample fine slag (FS) was more effective at high temperatures, with a removal efficiency of 83.64 %. Subsequently, we investigated the mercury removal performance of the different types of gasifier slag samples in the presence of SO2, NO, HCl, and H2S. The results indicated that sample FS exhibited better resistance to flue gas components. Regarding the adsorption mechanism, the mercury adsorption by RC was attributed to the action of surface-adsorbed hydroxyl groups, whereas the mercury adsorption by FS was due to chemical adsorption by oxygen. The low leaching toxicity further confirms the safety of GS. This study provided valuable guidance for the application of gasification slag in mercury removal processes.
{"title":"Using waste to treat waste: elemental mercury removal from flue gas by coal gasification slag","authors":"Yili Zhang , Xin Su , Hao Guo , Rihong Xiao , Xuebin Wang , Junying Zhang","doi":"10.1016/j.joei.2025.102364","DOIUrl":"10.1016/j.joei.2025.102364","url":null,"abstract":"<div><div>Coal gasification slag (GS), a solid waste from the coal chemical industry, holds promise as an efficient and environmentally friendly adsorbent. This study selected four typical gasification slag samples and conducted mercury removal experiments at different reaction temperatures. The results showed that sample refined carbon (RC) was suitable for low-temperature mercury removal, achieving an efficiency of 90.91 %, while sample fine slag (FS) was more effective at high temperatures, with a removal efficiency of 83.64 %. Subsequently, we investigated the mercury removal performance of the different types of gasifier slag samples in the presence of SO<sub>2</sub>, NO, HCl, and H<sub>2</sub>S. The results indicated that sample FS exhibited better resistance to flue gas components. Regarding the adsorption mechanism, the mercury adsorption by RC was attributed to the action of surface-adsorbed hydroxyl groups, whereas the mercury adsorption by FS was due to chemical adsorption by oxygen. The low leaching toxicity further confirms the safety of GS. This study provided valuable guidance for the application of gasification slag in mercury removal processes.</div></div>","PeriodicalId":17287,"journal":{"name":"Journal of The Energy Institute","volume":"124 ","pages":"Article 102364"},"PeriodicalIF":6.2,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145517258","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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