Article
Chemistry, Applied
Qimeng Duan, Hailiang Kou, Tao Li, Xiaojun Yin, Ke Zeng, Long Wang
Summary: Experimental investigations were conducted to study the effects of intake pressure and injection timing on combustion, performance, and emissions characteristics of a high compression ratio DI SI methanol engine. It was found that retarding injection timing could reduce ignition delay and burn duration, but decreased volumetric efficiency and combustion efficiency. Delaying spark timing could mitigate NO and CO emissions, but led to deterioration in heat release rate, thermal efficiency, and methanol/formaldehyde emissions. Overall, an injection timing range of -270 to -240 degrees CA aTDC would be optimal for good performance.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Energy & Fuels
Haoye Liu, Rafiu Olalere, Chongming Wang, Xiao Ma, Hongming Xu
Summary: 2-Methylfuran (MF) is considered a promising second-generation biofuel for spark ignition engines due to its better anti-knock ability and close lower heating value to conventional fuels. The study investigates the effects of engine control parameters on MF combustion at typical DISI engine operating conditions, showing that MF has a wider achievable spark timing range and more robustness to lean burn compared to gasoline and ethanol at high load. The combustion characteristics and heat release of MF are less sensitive to injection timings variations, but longer injection durations are required compared to gasoline to achieve the same engine load.
Article
Energy & Fuels
Hao Feng, Kaichang Lai, Zunqing Zheng, Sicong Lin, Xiang Wu, Qinglong Tang
Summary: The high octane number and high latent heat of vaporization of methanol are beneficial for suppressing knock and increasing compression ratio in spark ignition engines, leading to improved thermal efficiency. This study investigated the potential of high compression ratio and methanol direct injection (MDI) on the performance of a 1.5-liter spark ignition passenger car engine. The results showed that integrating a high compression ratio of 15.3 and MDI improved brake thermal efficiency (BTE) compared to low CR with gasoline, but also resulted in extended combustion durations and increased THC and CO emissions.
Article
Energy & Fuels
Saket Sahu, Parmod Kumar, Atul Dhar
Summary: The effect of start of injection (SOI) on the engine characteristics of a methanol-fueled direct injection spark ignition (DISI) engine is numerically studied in this paper. The simulations were performed using CONVERGE CFD software on a wall-guided, four-stroke gasoline direct injection (GDI) engine. It is observed that there exists an optimum injection timing for a given spark timing at which the best compromise is obtained between the performance and emissions. A maximum indicated thermal efficiency (ITE) of 41.66% is obtained in the case of -115 degrees CA ATDC SOI. Emissions like formaldehyde and soot are also found to be the lowest in this case. Engine's ITE is 36% higher for methanol fuel than gasoline when simulated by supplying the same energy input, keeping all the other parameters the same. The total hydrocarbon (THC), carbon monoxide (CO), and soot emissions are 58.2%, 68%, and 73.9% lower for optimized methanol injection timing as compared to gasoline. The NOX emissions are found to be higher for methanol than gasoline due to higher in-cylinder temperature in the case of methanol engine, which is due to higher heat release and proper combustion than gasoline.
Article
Thermodynamics
Binbin Wang, Hechun Wang, Chuanlei Yang, Deng Hu, Baoyin Duan, Yinyan Wang
Summary: This study investigates the impact of diesel-ignited ammonia/methanol engines on combustion and emission performance. It reveals that mixing methanol improves combustion efficiency, reduces ammonia escape, and decreases N2O emissions. The optimal mixing ratio is determined to be 8:2.
APPLIED THERMAL ENGINEERING
(2024)
Article
Chemistry, Multidisciplinary
Farhad Salek, Meisam Babaie, Amin Shakeri, Seyed Vahid Hosseini, Timothy Bodisco, Ali Zare
Summary: The study found that ammonia port injection significantly reduces NOx emissions, but has negative impacts on engine efficiency, CO, and HC emissions. It also decreases the minimum octane number required to prevent knock when added to the fuel mixture.
APPLIED SCIENCES-BASEL
(2021)
Article
Thermodynamics
Ke Chang, Changwei Ji, Shuofeng Wang, Jinxin Yang, Huaiyu Wang, Hao Meng, Dianqing Liu
Summary: A double spark plugs direct injection rotary engine was used in this study to investigate the effects of synchronous and asynchronous changes of ignition timing on combustion and emission performance. The three-dimensional dynamic model was established and validated by experimental data. The results show that setting the fuel injector toward the spark plug can reduce fuel distribution at the tail of the combustion chamber, and in-cylinder mixture inhomogeneity index increases with advance of ignition timing. Advancing the ignition timing of the tailing spark plug promotes the combustion process. Synchronous and asynchronous changes of ignition timing result in gradual increase of CA 0-10, while CA 10-90 change is more stable. Increasing ignition timing leads to higher in-cylinder pressure. Synchronous change shows slightly higher mean in-cylinder pressure compared to asynchronous change. Adopting a synchronous advance of 30 degrees CA achieves a peak pressure 16.4% higher than that of the original engine, with the lowest temperature and NOx mole fraction in the combustion chamber.
Article
Energy & Fuels
T. Sathish Kumar, B. Ashok
Summary: A novel approach has been explored to examine the most appropriate conditions for methanol flex-fuel operation in a direct injection spark ignition (DISI) engine. The research findings show significant improvement in brake thermal efficiency (BTE) from 18.27% to 27.73%. However, brake-specific fuel consumption (BSFC) increases, with M40 exhibiting the highest value of 506 g/kWhr. On the other hand, carbon monoxide (CO) and hydrocarbon (HC) emissions decrease, while carbon dioxide (CO2) and nitrogen oxides (NOx) emissions increase for blended fuel.
Article
Thermodynamics
Changming Gong, Jingzhen Sun, Fenghua Liu
Summary: The study showed that optimal injection timing of 110 degrees crank angle before top dead center and ignition timing of 21 degrees crank angle before top dead center can achieve the best compromise for a medium compression ratio direct-injection twin-spark plug synchronous ignition methanol engine under steady-state lean-burn conditions. Twin-spark plug synchronous ignition can ensure stable combustion and yield good performance with a medium compression ratio under lean burn conditions.
Article
Energy & Fuels
Hao Yuan, Karl Giles, Sipeng Zhu, Simeon Howson, Andrew Lewis, Sam Akehurst, Niall Turner, James Harris, Gavin Fowler, John Geddes
Summary: This study models the impact of direct water injection on the combustion process in a spark ignition engine, highlighting the thermodynamic and chemical-kinetic interactions between gasoline combustion and water injection. It shows that water injection can advance the combustion phasing by reducing in-cylinder temperature, thereby affecting the knock limited spark advance and improving engine performance.
Article
Energy & Fuels
Yanju Wei, Zengqiang Zhu, Shenghua Liu, He Liu, Zihang Shi, Zhixin Zeng
Summary: Methanol is considered a promising alternative fuel for SI engines, but there is a lack of investigation into the mixture formation process in heavy-duty methanol engines. This study found that the injection timing has a significant impact on mixture formation, combustion, and emissions. The premix and spray mode was found to be the optimal strategy for improving mixture homogeneity and reducing in-cylinder mixture temperature. Leaner mixture and lower mixture prolonged or retarded combustion characteristics were observed at certain injection timings. HC and CO emissions were influenced by the mixture richness in the combustion chamber and in-cylinder temperature. The premix and spray mode could improve engine efficiency and reduce both HC and CO emissions.
Article
Thermodynamics
Deborah Domingos da Rocha, Fabio de Castro Radicchi, Gustavo Santos Lopes, Marcello Francisco Brunocilla, Paulo Cesar de Ferreira Gomes, Nathalia Duarte Souza Alvarenga Santos, Augusto Cesar Teixeira Malaquias, Fernando Antonio Rodrigues Filho, Jose Guilherme Coelho Baeta
Summary: This study experimentally validated the impact of different water injection strategies on engine combustion parameters, finding that variations in water injection temperature had limited influence on fuel conversion efficiency, while proper injection timing and pressure calibration significantly reduced specific fuel consumption.
Article
Energy & Fuels
Xiaoyu Cong, Changwei Ji, Shuofeng Wang
Summary: The study found that blending DME can extend flame development and propagation periods, increase power output of the neat hydrogen engine, and reduce nitrogen oxides emissions. However, blending DME may increase cyclic variation due to weakened flame kernel and propagation process, but emissions can be controlled by adjusting the DME fraction.
Article
Thermodynamics
Qimeng Duan, Tao Li, Dong Liu, Xiaojun Yin, Ke Zeng, Long Wang
Summary: The study demonstrates that using multiple-injection strategies can improve the combustion efficiency and stability of methanol engines, while reducing cycle-to-cycle variations. In experimental evaluations, the triple-injection strategy shows superior performance, especially in terms of thermal efficiency and nitrogen oxide emissions.
APPLIED THERMAL ENGINEERING
(2024)
Article
Thermodynamics
Ziyoung Lee, Sungwook Park
Summary: The research proposed an index for predicting particle number (PN) emissions from a direct injection spark ignition engine for various fuel compositions and injection strategies based on the correlation between PN emissions and various parameters. Experiments were conducted using a single-cylinder engine with different fuel blends and injection timings, showing that dodecane blended fuel increased PN emissions due to its higher viscosity, while divinylbenzene blend promoted particle growth leading to increased particles emitted. The proposed PN index showed high predictability with a correlation coefficient of 0.9354.
ENERGY CONVERSION AND MANAGEMENT
(2021)
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.