Article
Energy & Fuels
Yuhua Liu, Jingzhang Liu, Qinggang Lyu, Jianguo Zhu, Fei Pan
Summary: In this study, the microstructure changes of fuel during preheating process were analyzed to reveal the impact on particle change behavior during combustion. It was found that during preheating, the main forms of N, C, and O elements in coal were pyrrole, hydrocarbon, and carbon-oxygen single bond respectively.
Article
Thermodynamics
Siqi Liu, Yanqing Niu, Liping Wen, Yaqian Kang, Yufeng Wang, Denghui Wang, Shi'en Hui
Summary: The study focuses on the impact of ash minerals and the mechanisms of ash film and ash dilution on char reactivity during the burnout stage. The research aims to provide detailed data on the variation of ash film fraction with carbon conversion ratio, and integrate it into the kinetic model to predict the behavior of ash minerals during combustion.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Aoyang Zhang, Xiaowei Liu, Yishu Xu, Tianpeng Zhang, Minghou Xu
Summary: An improved model of fine particulate matter formation, which combines the mechanisms of mineral coalescence and char fragmentation under different pulverized coal combustion environments, has been developed. The model includes a three-dimensional sub-model of char particles and a sub-model of mineral melting coalescence. The model has shown good fitting effects with experimental data and provides a better understanding of the particulate matter formation process.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Energy & Fuels
Zhenghong Zhao, Zewu Zhang, Xiaojian Zha, Ge Gao, Xiaoshan Li, Fan Wu, Cong Luo, Liqi Zhang
Summary: Moderate or intense low-oxy dilution oxy-fuel (MILD-oxy) combustion can synergistically reduce CO2 and NOx emissions. Numerical simulations show that increasing O2 concentration weakens flue gas recirculation and promotes combustion intensity. Dry recycle mode has a more uniform temperature distribution, while wet recycle mode achieves diffusion/kinetics-controlled MILD regime. Dry recycle mode slows down coal char burnout, while wet recycle mode has more potential in achieving low NOx emission.
Article
Energy & Fuels
Fangqi Liu, Jingying Xu, Congming Yu, Jianqun Wu, Jingkun Han, Dunxi Yu
Summary: The novel compound additive prepared from kaolin and limestone shows promising prospects for reducing the emission of PM2.5. The addition of kaolin or limestone alone can reduce the aerosol emissions in the size range of 0.3-2.5 μm but increase the emissions of ultrafine aerosols less than 0.3 μm. However, the addition of the kaolin-limestone additive leads to a significant reduction in both PM0.3 and PM0.3-2.5, resulting in a high reduction of PM2.5.
Article
Energy & Fuels
Sheng Qi, Zhihua Wang, Mario Costa, Yong He, Kefa Cen
Summary: The ignition and combustion characteristics of biomass and lignite particles were found to be homogeneous, while bituminous coal and anthracite particles ignited heterogeneously. Biomass particles ignited earlier than coal particles and the ignition delay time decreased with increasing volatile content in coal. Replacing N2 with CO2 delayed the ignition of all solid fuels and extended the burnout time of volatiles, leading to less intense combustion in a CO2/O2 environment compared to N2/O2 due to lower binary diffusivity of O2 in CO2 and higher volumetric heat capacity of CO2.
Article
Chemistry, Applied
Ao Zhou, Wenjing Ma, Renhui Ruan, Yuan Li, Qingfu Zhang, Rui Mao, Shilin Yu, Shuanghui Deng, Houzhang Tan, Xuebin Wang
Summary: This study investigates the formation characteristics of particulate matter (PM10) produced by the co-combustion of sludge and pulverized coal. The results show that the furnace temperature and sludge mixing ratio have an impact on the mass-based particle size distribution and elemental composition of PM10. Increasing the furnace temperature increases the yield of PM10, while increasing the sludge mixing ratio reduces the yield of PM10.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Thermodynamics
Luis I. Diez, Alexander Garcia-Mariaca, Paula Canalis, Eva Llera
Summary: The oxy-fuel combustion of two torrefied biomasses is experimentally investigated in this study. It is found that increasing the share of torrefied biomass leads to significantly higher burnout degrees and CO2 conversion rates. When torrefied biomass is used alone, the formation rates of NO are reduced. The best results are obtained with 25% H2O atmospheres in most cases.
Article
Energy & Fuels
Siqi Liu, Yanqing Niu, Liping Wen, Yang Liang, Bokang Yan, Denghui Wang, Shi'en Hui
Summary: This research investigates the impact of ash content on the fraction of ash film in pulverized coal combustion, and how it varies under different conditions. The results demonstrate that the ash film fraction increases with temperature and carbon conversion ratio, but decreases with larger coal particle sizes.
FRONTIERS IN ENERGY
(2021)
Article
Geochemistry & Geophysics
Ulung Muhammad Sutopo, Erda Rahmilaila Desfitri, Yukio Hayakawa, Shinji Kambara
Summary: The study found that all mineral oxides had good correlations with arsenic, boron had good relationships with aluminum, calcium, and magnesium, chromium had good correlations with potassium and calcium, and interactions of fluorine with Fe2O3, K2O, and Al2O3 were predicted. The effects of mineral oxides on selenium partitioning were not observed. The inhibition order of trace elements by mineral oxides was determined. These results will be useful for controlling trace element emissions.
Article
Energy & Fuels
Ming Lei, Cen Sun, Yanchao Zhang
Summary: The study found that pressurized pyrolysis intensified the decomposition of aromatic ring structure and hydroxyl hydrogen bonds in coal char, leading to the formation of low-substituted single rings, as well as shortening of aliphatic chains and carboxyl groups in char. Pressurized pyrolysis also increased the graphitization degree of char and inhibited the decomposition of low-temperature minerals. Furnace temperature had a more significant impact on mineral transformations compared to furnace pressure. Additionally, in pressurized conditions, the primary minerals in coal ash remained consistent but their relative contents changed, with combustion temperature influencing mineral transformations. The mixture of O-2/CO(2) restrained the decomposition of low-temperature minerals and formation of high-temperature minerals, with furnace temperature being the primary factor influencing ash mineral transformations.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2021)
Article
Energy & Fuels
Shuai Wang, Yanqing Niu, Guangqing Zhu, Yiyu Ding, Xiaolian Guo, Shi'en Hui
Summary: This study found that increasing the combustion temperature can promote both the formation and destruction of NO during the oxidation of high-temperature preheated pulverized coal. The increase in NO formation rate was steeper than its destruction rate, leading to an overall increase in NO emissions.
JOURNAL OF THE ENERGY INSTITUTE
(2021)
Article
Energy & Fuels
Sheng Chen, Mingkai Cheng, Jingying Xu, Xiaowei Liu, Dunxi Yu, Minghou Xu
Summary: This study developed a numerical framework to predict the effect of additives on reducing particulate matter during coal combustion and validated the reduction effect when burning high-sodium Zhundong coal in a lab-scale furnace. The experimental results showed that adding kaolin can significantly reduce the mass yield of smaller particulate matter (PM0.3), with chemical adsorption being the dominant mechanism for PM reduction.
Article
Energy & Fuels
Mingzi Xu, Changdong Sheng
Summary: In this study, a mathematical model based on the plug flow model and coarse fly ash particles' fragmentation model was developed to describe the behavior and evolution of ash formation and the influence of biomass feeding rate and flue gas cooling rate on ash properties. The model was validated using literature data and was applied to study ash formation characteristics in practical boiler pulverized fuel combustion and SO2 sulfation cases. The results demonstrate that the model can reasonably describe ash formation and the effects of biomass feeding rate and flue gas cooling rate on particle size distributions and elemental compositions of PM10.
Article
Energy & Fuels
Jingkun Han, Dunxi Yu, Jianqun Wu, Xin Yu, Fangqi Liu, Minghou Xu
Summary: Torrefaction technology has positive effects on ash fouling during biomass combustion and co-combustion. The interactions between fuels during co-combustion inhibit the formation of inside fouling deposits while the incorporation of alkalis in aluminosilicates promotes the growth of outside deposits. Torrefaction reduces the formation of chlorides and sulfates, thus inhibiting the inside deposition. However, the elemental repartitioning during torrefaction leads to more retention of alkalis, which aggravates the formation of mixed aluminosilicates and favors the outside deposition.
Article
Energy & Fuels
Yingna Du, Chen Huang, Wei Jiang, Qiangwei Yan, Yongfei Li, Gang Chen
Summary: In this study, anionic surfactants modified hydrotalcite was used as a flow improver for crude oil under low-temperature conditions. The modified hydrotalcite showed a significant viscosity reduction effect on crude oil. The mechanism of the modified hydrotalcite on viscosity and pour point of crude oil was explored through characterization and analysis of the modified hydrotalcite and oil samples.
Article
Energy & Fuels
Mohammad Saeid Rostami, Mohammad Mehdi Khodaei
Summary: In this study, a hybrid structure, MIL-53(Al)@MWCNT, was synthesized by combining MIL-53(Al) particles and -COOH functionalized multi-walled carbon nanotube (MWCNT). The hybrid structure was then embedded in a polyethersulfone (PES) polymer matrix to prepare a mixed matrix membrane (MMM) for CO2/CH4 and CO2/N2 separation. The addition of MWCNTs prevented MIL-53(Al) aggregation, improved membrane mechanical properties, and enhanced gas separation efficiency.
Article
Energy & Fuels
Yunlong Li, Desheng Huang, Xiaomeng Dong, Daoyong Yang
Summary: This study develops theoretical and experimental techniques to determine the phase behavior and physical properties of DME/flue gas/water/heavy oil systems. Eight constant composition expansion (CCE) tests are conducted to obtain new experimental data. A thermodynamic model is used to accurately predict saturation pressure and swelling factors, as well as the phase boundaries of N2/heavy oil systems and DME/CO2/heavy oil systems, with high accuracy.
Article
Energy & Fuels
Morteza Afkhamipour, Ebad Seifi, Arash Esmaeili, Mohammad Shamsi, Tohid N. Borhani
Summary: Non-conventional amines are being researched worldwide to overcome the limitations of traditional amines like MEA and MDEA. Adequate process and thermodynamic models are crucial for understanding the applicability and performance of these amines in CO2 absorption, but studies on process modeling for these amines are limited. This study used rate-based modeling and Deshmukh-Mather method to model CO2 absorption by DETA solution in a packed column, validated the model with experimental data, and conducted a sensitivity analysis of mass transfer correlations. The study also compared the CO2 absorption efficiency of DETA solution with an ionic solvent [bmim]-[PF6] and highlighted the importance of finding optimum operational parameters for maximum absorption efficiency.
Article
Energy & Fuels
Arastoo Abdi, Mohamad Awarke, M. Reza Malayeri, Masoud Riazi
Summary: The utilization of smart water in EOR operations has gained attention, but more research is needed to understand the complex mechanisms involved. This study investigated the interfacial tension between smart water and crude oil, considering factors such as salt, pH, asphaltene type, and aged smart water. The results revealed that the hydration of ions in smart water plays a key role in its efficacy, with acidic and basic asphaltene acting as intrinsic surfactants. The pH also influenced the interfacial tension, and the aged smart water's interaction with crude oil depended on asphaltene type, salt, and salinity.
Article
Energy & Fuels
Dongao Zhu, Kun Zhu, Lixian Xu, Haiyan Huang, Jing He, Wenshuai Zhu, Huaming Li, Wei Jiang
Summary: In this study, cobalt-based metal-organic frameworks (Co-based MOFs) were used as supports and co-catalysts to confine the NHPI catalyst, solving the leaching issue. The NHPI@Co-MOF with carboxyl groups exhibited stronger acidity and facilitated the generation of active oxygen radicals O2•, resulting in enhanced catalytic activity. This research provides valuable insights into the selection of suitable organic linkers and broadens the research horizon of MOF hybrids in efficient oxidative desulfurization (ODS) applications.
Article
Energy & Fuels
Edwin G. Hoyos, Gloria Amo-Duodu, U. Gulsum Kiral, Laura Vargas-Estrada, Raquel Lebrero, Rail Munoz
Summary: This study investigated the impact of carbon-coated zero-valent nanoparticle concentration on photosynthetic biogas upgrading. The addition of nanoparticles significantly increased microalgae productivity and enhanced nitrogen and phosphorus assimilation. The presence of nanoparticles also improved the quality of biomethane produced.
Article
Energy & Fuels
Yao Xiao, Asma Leghari, Linfeng Liu, Fangchao Yu, Ming Gao, Lu Ding, Yu Yang, Xueli Chen, Xiaoyu Yan, Fuchen Wang
Summary: Iron is added as a flocculant in wastewater treatment and the hydrothermal carbonization (HTC) of sludge produces wastewater containing Fe. This study investigates the effect of aqueous phase (AP) recycling on hydrochar properties, iron evolution and environmental assessment during HTC of sludge. The results show that AP recycling process improves the dewatering performance of hydrochar and facilitates the recovery of Fe from the liquid phase.
Article
Energy & Fuels
He Liang, Tao Wang, Zhenmin Luo, Jianliang Yu, Weizhai Yi, Fangming Cheng, Jingyu Zhao, Xingqing Yan, Jun Deng, Jihao Shi
Summary: This study investigated the influence of inhibitors (carbon dioxide, nitrogen, and heptafluoropropane) on the lower flammability limit of hydrogen and determined the critical inhibitory concentration needed for complete suppression. The impact of inhibitors on explosive characteristics was evaluated, and the inhibitory mechanism was analyzed with chemical kinetics. The results showed that with the increase of inhibitor quantity, the lower flammability limit of hydrogen also increased. The research findings can contribute to the safe utilization of hydrogen energy.
Article
Energy & Fuels
Zonghui Liu, Zhongze Zhang, Yali Zhou, Ziling Wang, Mingyang Du, Zhe Wen, Bing Yan, Qingxiang Ma, Na Liu, Bing Xue
Summary: In this study, high-performance solid catalysts based on phosphotungstic acid (HPW) supported on Zr-SBA-15 were synthesized and evaluated for the one-pot conversion of furfural (FUR) to γ-valerolactone (GVL). The catalysts were characterized using various techniques, and the ratio of HPW and Zr was found to significantly affect the selectivity of GVL. The HPW/Zr-SBA-15 (2-4-15) catalyst exhibited the highest GVL yield (83%) under optimized reaction conditions, and it was determined that a balance between Bronsted acid sites (BAS) and Lewis acid sites (LAS) was crucial for achieving higher catalytic performance. The reaction parameters and catalyst stability were also investigated.
Article
Energy & Fuels
Michael Stoehr, Stephan Ruoff, Bastian Rauch, Wolfgang Meier, Patrick Le Clercq
Summary: As part of the global energy transition, an experimental study was conducted to understand the effects of different fuel properties on droplet vaporization for various conventional and alternative fuels. The study utilized a flow channel to measure the evolution of droplet diameters over time and distance. The results revealed the temperature-dependent effects of physical properties, such as boiling point, liquid density, and enthalpy of vaporization, and showed the complex interactions of preferential vaporization and temperature-dependent influences of physical properties for multi-component fuels.
Article
Energy & Fuels
Yuan Zhuang, Ruikang Wu, Xinyan Wang, Rui Zhai, Changyong Gao
Summary: Through experimental validation and optimization of the chemical kinetic model, it was found that methanol can accelerate the oxidation reaction of ammonia, and methanol can be rapidly oxidized at high concentration. HO2 was found to generate a significant amount of OH radicals, facilitating the oxidation of methanol and ammonia. Rating: 7.5/10.
Article
Energy & Fuels
Radwan M. EL-Zohairy, Ahmed S. Attia, A. S. Huzayyin, Ahmed I. EL-Seesy
Summary: This paper presents a lab-scale experimental study on the impact of diethyl ether (DEE) as an additive to waste cooking oil biodiesel with Jet A-1 on combustion and emission features of a swirl-stabilized premixed flame. The addition of DEE to biodiesel significantly affects the flame temperature distribution and emissions. The W20D20 blend of DEE, biodiesel, and Jet A-1 shows similar flame temperature distribution to Jet A-1 and significantly reduces UHC, CO, and NOx emissions compared to Jet A-1.
Article
Energy & Fuels
Jiang Bian, Ziyuan Zhao, Yang Liu, Ran Cheng, Xuerui Zang, Xuewen Cao
Summary: This study presents a novel method for ammonia separation using supersonic flow and develops a mathematical model to investigate the condensation phenomenon. The results demonstrate that the L-P nucleation model accurately characterizes the nucleation process of ammonia at low temperatures. Numerical simulations also show that increasing pressure and concentration can enhance ammonia condensation efficiency.
Article
Energy & Fuels
Shiyuan Pan, Xiaodan Shi, Beibei Dong, Jan Skvaril, Haoran Zhang, Yongtu Liang, Hailong Li
Summary: Integrating CO2 capture with biomass-fired combined heat and power (bio-CHP) plants is a promising method for achieving negative emissions. This study develops a reliable data-driven model based on the Transformer architecture to predict the flowrate and CO2 concentration of flue gas in real time. The model validation shows high prediction accuracy, and the potential impact of meteorological parameters on model accuracy is assessed. The results demonstrate that the Transformer model outperforms other models and using near-infrared spectral data as input features improves the prediction accuracy.