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
Shuo Zhang, Zhenfeng Zhao, Chuncun Yu, Zhao Geng, Zhenhuan Yang, Shangxue Wang
Summary: This study aims to solve the cold-start problem of heavy fuel piston engines and develop a cold-start control strategy. The experiments show that the engine can start quickly and smoothly within a specific range of control parameters, and the cold-start time and IMEP are most sensitive to the injection advance angle.
Article
Thermodynamics
Tiankui Zhu, Zhan Gao, Yuxiao Qiu, Xin Yan, Lei Zhu, Zhen Huang
Summary: Polyoxymethylene dimethyl ethers (PODE) and methanol show promise as alternative fuels for internal combustion engines. A modified gasoline engine was used to study the combustion characteristics of a dual-fuel SACI engine fueled with direct injection PODE and port injection methanol. The study analyzed the effects of PODE mass ratio, spark ignition timing, and start of injection timing. The results showed multiple heat-release stages during dual-fuel SACI combustion and demonstrated the potential for high brake thermal efficiency and low hydrocarbon emissions with the appropriate control of parameters.
APPLIED THERMAL ENGINEERING
(2023)
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
Ke Chang, Changwei Ji, Shuofeng Wang, Jinxin Yang, Hao Meng, Huaiyu Wang, Gu Xin
Summary: The study shows that direct injection leads to fuel stratification in the combustion chamber, while dual spark plug ignition can improve combustion efficiency. However, using only the leading spark plug for ignition results in a large unburned area, affecting power performance.
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
Thermodynamics
Fangsi Ren, Naoto Takehara, Shinji Nakaya, Mitsuhiro Tsue, Ryo Adachi, Kunihiko Suganuma
Summary: The influences of spark-plug mounting angle on spark ignition in high velocity flows were investigated. Negative mounting angle resulted in early short circuits/restrikes, while positive mounting angles led to longer discharge channel length and induction time. The shape and induction time of the flame kernel varied with different flow velocities.
INTERNATIONAL JOURNAL OF ENGINE RESEARCH
(2023)
Article
Engineering, Multidisciplinary
Huichao Jiao, Jinxiang Liu, Run Zou, Nana Wang
Summary: The comprehensive optimization of the ignition environment in the small spark ignition Wankel rotary engine showed that engine performance was largely limited by ignition chamber characteristics, including volume and spark plug channel diameter, which affected short-term and long-term flow losses, combustion speed, and operational stability.
ENGINEERING APPLICATIONS OF COMPUTATIONAL FLUID MECHANICS
(2021)
Review
Energy & Fuels
Anh Tuan Hoang, Sandro Nizetic, Van Viet Pham, Anh Tuan Le, Van Ga Bui, Van Vang Le
Summary: This paper discusses the production process and properties of DMF derived from biomass, as well as the oxidation, pyrolysis mechanisms, and combustion characteristics of DMF in engines. DMF could potentially become a fuel for both SI and CI engines, but optimization of the production process is necessary before application.
Article
Chemistry, Applied
Antonio Garcia, Javier Monsalve-Serrano, Carlos Mico, Maria Guzman-Mendoza
Summary: This study investigates the feasibility of using neat methanol in high-efficiency compression ignition engines and its potential to reduce CO2 emissions. The research reveals that combustion of neat methanol poses challenges due to its low ignition capability, requiring higher compression ratios and temperatures than diesel. However, despite its lower energy density, methanol combustion achieves comparable efficiency with remarkable improvements in NOx and soot emissions.
FUEL PROCESSING TECHNOLOGY
(2023)
Article
Chemistry, Applied
Ahmad O. Hasan, Ahmed I. Osman, Ala'a H. Al-Muhtaseb, Hani Al-Rawashdeh, Ahmad Abu-jrai, Riad Ahmad, Mohamed R. Gomaa, Tanmay J. Deka, David W. Rooney
Summary: The study found that blended methanol can reduce HC and CO emissions in tailpipe, but increase NOx emissions; smoke emissions significantly decrease as the percentage of methanol in blends increases. Pure diesel showed higher brake thermal efficiency and lower fuel consumption at all engine loads.
FUEL PROCESSING TECHNOLOGY
(2021)
Article
Energy & Fuels
Jianan Wei, Hongqing Feng, Haifeng Liu, Hongyan Zhu, Zongyu Yue, Mingfa Yao
Summary: The study showed that adding 10% ethanol to iso-octane can accelerate combustion speed with higher heat release rate and pressure rise rate after knocking onset. Additionally, blending methanol with iso-octane enhances knock intensity, particularly at a 30% blend ratio. The new parameter I, measuring the interaction between flame core and pressure wave, revealed that methanol induces more intense knock compared to iso-octane and ethanol.
Article
Thermodynamics
Qinhao Fan, Shang Liu, Yunliang Qi, Kaiyuan Cai, Zhi Wang
Summary: Blending ethanol into non-oxygenated gasoline can achieve stable compression ignition, high thermal efficiency, and low particle emission under SICI mode. Ethanol addition can reduce knock tendency, but synergistic effects with aromatics may result in higher knock intensity when maintaining the same fuel type.
Article
Thermodynamics
Haiyan Chen, Zhongjie Shi, Yue Wu, Yikai Li, Dongfang Wang
Summary: This paper investigates the effect of injection pressure on the two-stage ignition process of fuel spray under cold-start conditions and establishes an analytical model accordingly. The experimental results show that increasing injection pressure leads to a decrease in low-temperature ignition delay time and an increase in cool flame propagation time, resulting in a non-monotonic trend for high-temperature ignition delay.
APPLIED THERMAL ENGINEERING
(2023)
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
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.