Article
Thermodynamics
M. Zuhaib Akram, Fanhua Ma, M. Waqar Akram
Summary: The study demonstrates that under hydrogen enrichment conditions, the utilization of H-2 and hydrocarbon fuels can reduce the formation of benzene and pyrene in combustion products, mitigate CO2 emissions, and decrease the mass concentration and particle number density of soot.
ENERGY CONVERSION AND MANAGEMENT
(2022)
Article
Energy & Fuels
M. Zuhaib Akram, Fanhua Ma, Muhammad Aziz, Yangbo Deng, Han Wu
Summary: The use of hydrogen as a zero-carbon fuel alongside hydrocarbon fuels can effectively reduce the environmental impact and dependence on nonrenewable energy resources caused by internal combustion engines. A numerical approach was conducted to investigate the influence of hydrogen on combustion kinetics, soot formation, and NOx emission of hydrocarbon fuel under different flame conditions. The results demonstrated that hydrogen hindered the formation of soot, carbon monoxide, carbon dioxide, and polycyclic aromatic hydrocarbons by reducing small chain hydrocarbons. Furthermore, the presence of hydrogen decreased NO3 emissions by reducing the molar fraction of small chain hydrocarbons and C-H-O related species. C3H3 was found to play a dominant role in reducing CO2 and NO3 emissions, while C2H2 and C5H4CH2 controlled the formation of soot precursors in hydrocarbon fuel flames. Additionally, C2H2 limited the emission of NH3 in diffusion flame conditions.
Article
Thermodynamics
Kevin Gleason, Alessandro Gomez
Summary: We performed measurements of light scattering of soot in atmospheric pressure counterflow diffusion flames, comparing a baseline ethylene flame and a toluene-seeded flame. The goal was to bypass the formation of the first aromatic ring and assess the impact of toluene on soot formation. The results showed that doping with toluene increased the aromatic content and soot volume fraction, while only modestly affecting the soot number density and nucleation rate. Nucleation conditions had a significant impact on the size of the initial particle, ultimately affecting subsequent growth.
COMBUSTION AND FLAME
(2023)
Article
Energy & Fuels
Mariam Nasser Al Shebli, Abhijeet Raj, Mirella Elkadi, Dalaver Anjum, Gerardo D. J. Pena, Azhagapillai Prabhu
Summary: Blending gasoline with oxygenated aromatics can reduce soot emission and improve the properties of soot particles.
Article
Energy & Fuels
Mohammed A. Fayad, Hind A. Al-Salihi, Hayder A. Dhahad, Farag M. Mohammed, Bashar R. Al-Ogidi
Summary: The study showed that the use of post-injection strategy and alternative fuels can reduce nitrogen oxide emissions from diesel engines, while also lowering the concentration of particulate matter and altering the characteristics of particles.
ENERGY SOURCES PART A-RECOVERY UTILIZATION AND ENVIRONMENTAL EFFECTS
(2021)
Review
Engineering, Environmental
Tao Cai, Dan Zhao, Ephraim Gutmark
Summary: This article provides an overview of the latest research progress in ammonia combustion, summarizing the reaction mechanisms, NOx generation mechanism and mitigation strategies, and the impact of ammonia on soot formation. Furthermore, technical challenges and future research prospects in ammonia combustion with lower NOx emissions are discussed.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Energy & Fuels
Mohammed A. Fayad, Slafa I. Ibrahim, Salman H. Omran, Francisco J. Martos, Tawfik Badawy, Ayad M. Al Jubori, Hayder A. Dhahad, Miqdam T. Chaichan
Summary: This study investigated the effects of adding CuO2 nanoparticles and exhaust gas recirculation (EGR) on combustion characteristics and soot nanoparticle morphology in a diesel engine. The results showed that the addition of CuO2 nanoparticles improved combustion characteristics and reduced exhaust emissions. Furthermore, combining CuO2 with EGR technology further reduced NOX emissions.
Article
Energy & Fuels
Gelu Varghese, Khizer Saeed, Xinming Lu, Ken J. Rutt
Summary: This study investigates the effects of biodiesel degree of unsaturation and chain length on NOx emissions in engines and presents a methodology to decouple these effects. The results show that NOx emissions increase with increasing degree of unsaturation, peaking at an average degree of unsaturation of 1.5. Shorter chain length esters are found to result in lower NOx emissions, with a decrease observed until a chain length factor of 0.765 is reached.
JOURNAL OF THE ENERGY INSTITUTE
(2022)
Review
Green & Sustainable Science & Technology
Wai Siong Chai, Yulei Bao, Pengfei Jin, Guang Tang, Lei Zhou
Summary: The combustion of fuels for energy generation is crucial for human activities, but it results in emissions that cause environmental complications and health risks. The replacement of conventional fuels for zero carbon emission is important, with ammonia offering advantages over hydrogen as a carbon-free fuel, but facing challenges such as low burning velocity and high emissions. Therefore, the study of secondary fuels like hydrogen and methane to assist ammonia combustion is essential.
RENEWABLE & SUSTAINABLE ENERGY REVIEWS
(2021)
Article
Energy & Fuels
Manish Kumar, Srinibas Karmakar, Cheng Tung Chong
Summary: The scientific community is currently researching new alternative fuels to meet the growing energy demand for domestic energy security, fuel supply diversity, and long-term fuel cost reduction. Alcohol-based fuels and acetone-butanol-ethanol mixture are potential candidates for clean combustion to drive gas turbine engines. However, suitable alternatives for micro gas turbine fuels are still in early stages of development.
Article
Thermodynamics
Kevin Wan, Julien Manin, Hyung Sub Sim, Ioannis Karathanassis
Summary: Time-resolved formation of soot and PAHs from gasoline and diesel combustion was studied using DBI and LIF techniques. The results show that increasing temperature reduces the delay time and enhances the formation rate of both soot and PAHs. The mass-based YSI is a better predictor of sooting propensity than the mole-based YSI.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Christopher Betrancourt, Damien Aubagnac-Karkar, Xavier Mercier, Abderrahman El-Bakali, Pascale Desgroux
Summary: This study investigates nucleation flames and their contribution to soot formation and growth. Experimental measurements and modeling simulations of flames with different equivalence ratios were conducted. The results show that nucleation flames produce very small-sized soot particles with negligible growth. The study validates the capability of the combustion model to predict soot volume fraction and emphasizes the need for improvements in particle inception modeling.
COMBUSTION AND FLAME
(2022)
Article
Thermodynamics
Peng Liu, Zepeng Li, William L. Roberts Clean
Summary: This study systematically investigated the growth mechanism of PAHs with a 5-membered ring and their reaction characteristics under flame conditions. The results showed that H abstraction reactions on the 5-membered ring were unfavorable, while subsequent C2H2 addition reactions were most favorable. The formation of planar PAHs with C2H substitution was found to be more favorable compared to the formation of new 5-membered rings and 6-membered rings.
COMBUSTION AND FLAME
(2021)
Article
Energy & Fuels
A. V. Minakov, V. A. Kuznetsov, I. S. Anufriev, E. P. Kopyev
Summary: This study numerically investigates the combustion of diesel fuel in a pre-chamber vortex burner with a steam blast atomizer. The results show that the burner can achieve almost complete combustion while meeting environmental emission standards.
Article
Environmental Sciences
Cavan McCaffery, Hanwei Zhu, Georgios Karavalakis, Thomas D. Durbin, J. Wayne Miller, Kent C. Johnson
Summary: This study evaluated the gaseous and particulate emissions from a Tier 2 oceangoing vessel using two emission control area (ECA) compliant fuels. Results showed that the novel ultra-low sulfur heavy fuel oil (ULSHFO) had slightly higher nitrogen oxide (NOx) emissions for both the main and auxiliary engines, and significantly increased NOx emissions for the auxiliary boiler. Additionally, ULSHFO had higher PM2.5 and black carbon emissions, with little contribution of sulfate due to the low sulfur content in both fuels.
ATMOSPHERIC ENVIRONMENT
(2021)
Article
Thermodynamics
Yifan Yang, Haodong Zhang, Linye Li, Mingming Gu, Xi Xia, Fei Qi
Summary: This paper investigates the formation of a blue whirl by controlling tangential and radial airflows. By using a unique fire whirl apparatus, the blue whirl can be formed directly upon ignition without going through the transient phase. The study also discovers new flame regimes and explores the mechanism behind the formation and transition of the blue whirl.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Xiaobin Qi, Songyan Gao, Zhiping Zhu, Qinggang Lyu, Haixia Zhang
Summary: This study experimentally investigated the propagation characteristics of reverse combustion under oxygen-limited and enriched conditions. The contribution of volatiles gas-phase oxidation and char surface oxidation to reverse combustion was evaluated. The results showed that oxygen enrichment expanded the operating range of oxygen flow rate for reverse combustion and enhanced the low-temperature oxidation of the solid fuel. The findings provide a better understanding of the driving mechanism of reverse combustion and have important implications for efficient thermal conversion of solid fuels.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Bingjie Chen, Peng Liu, Bingzhi Liu, Zhandong Wang, Xiang Gao, William L. Roberts
Summary: In this study, the low temperature oxidation of 1,2,4-trimethylbenzene was investigated using experiments and numerical simulations. The results showed the presence of toxic oxygenated aromatic compounds and proposed potential formation pathways. The numerical simulations accurately predicted the mole fractions of most compounds, but some compounds were missing.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Meng Sui, Zhiheng Zhu, Fashe Li, Hua Wang
Summary: The effect of adding ferrocene as a combustion catalyst to Jatropha biodiesel on its pyrolysis and combustion performance is investigated. The results show that adding ferrocene reduces activation energy and harmful emissions while improving combustion efficiency.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Manaf Sheyyab, Mohammed Abdulrahman, Subharaj Hossain, Patrick T. Lynch, Eric K. Mayhew, Kenneth Brezinsky
Summary: Fuel surrogates, simplified representations of complex fuels, accurately model speciation results and reaction kinetics, reproduce the ignition quality and chemical functional group compositions of their parent fuels.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Yan Wang, Shumeng Xie, Hannes Bottler, Yiqing Wang, Xinyi Chen, Arne Scholtissek, Christian Hasse, Zheng Chen
Summary: This study investigates how flow affects the ignition and transition process of a cool flame. The results show that the ignition energy determines the highest temperature and the strain rate influences the flame propagation and the transition from cool flame to hot flame.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Tanusree Chatterjee, Mengyuan Wang, Goutham Kukkadapu, Chih-Jen Sung, William J. Pitz
Summary: Cycloalkanes, including cyclohexane, are important hydrocarbons in transportation fuels. However, limited oxidation data at low-to-intermediate temperatures and inadequate predictive ability of kinetic models have hindered the understanding and improvement of cyclohexane oxidation. This study provides experimental and modeling results to develop a more accurate kinetic model for cyclohexane oxidation.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Tao Wu, Erik Hagen, Haiyang Wang, Dylan J. Kline, Michael R. Zachariah, Carole Rossi
Summary: It was found that incorporating CuO into Al/I2O5 can significantly reduce the ignition time and enhance the combustion performance. The optimum composition of 80/20 wt% of I2O5/CuO shows a 30 times shorter ignition time and produces a peak pressure and pressurization rate 4 and 26 times greater than traditional Al/I2O5. A series of characterizations helped unravel the cause of improvement and propose a reaction mechanism for this ternary Al/I2O5/CuO system. This study proposes a facile, inexpensive, and efficient way to enhance the combustion performance of Al/I2O5 biocidal nanoenergetic materials.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Mahmoud Gadalla, Shervin Karimkashi, Islam Kabil, Ossi Kaario, Tianfeng Lu, Ville Vuorinen
Summary: In this study, the flame initiation process in dual-fuel spray assisted combustion is explored through scale-resolved simulations, providing numerical evidence on the initiation of premixed flames. It is found that there is a transient mixed-mode combustion phase after ignition, followed by a primarily deflagrative combustion mode. The interactions between turbulence and premixed flame front are characterized in the corrugated regime.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Neeraj Kumar Pradhan, Arindrajit Chowdhury, Debasis Chakraborty, Neeraj Kumbhakarna
Summary: In this study, a modified model for predicting the burn rate of composite solid propellants is proposed. The model has been validated against experimental and theoretical results, and it outperforms existing models in all cases considered. The model is highly robust and provides results quickly, making it highly efficient in terms of time, effort, and computational resources.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Lili Ye, Zhihe Zhang, Fan Wang, Xiaodong Wang, Yiming Lu, Lei Zhang
Summary: This study investigated the pyrolysis mechanism of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) explosive using ab initio and kinetic modeling simulations. The results showed that N-NO2 bond fission and C-H beta-scission are important channels in the decomposition of HMX.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Andrei N. Lipatnikov, Hsuchew Lee, Peng Dai, Minping Wan, Vladimir A. Sabelnikov
Summary: This study investigates the importance of thermodiffusive and hydrodynamic instabilities of laminar flames in turbulent flows through numerical simulations. The analysis suggests that laminar flame instabilities play a minor role at sufficiently high Karlovitz numbers.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Shijie Xu, Yue Qiu, Leilei Xu, Jianqing Huang, Shen Li, Elna J. K. Nilsson, Zhongshan Li, Weiwei Cai, Marcus Alden, Xue-Song Bai
Summary: Metal powder is a promising carbon-free and recyclable energy carrier. In this study, a computational model for the combustion and phase change of micron-sized iron particles was proposed and validated. The model successfully captures the melting, surface reactions, cooling, and solidification processes. The study also reveals a two-stage solidification phenomenon and identifies a diffusion-controlled mechanism during the melting process. The reaction between iron and CH4/O2/N2 flame products is found to play a significant role in the iron combustion process.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Khalid Aljohani, Abd El-Sabor Mohamed, Haitao Lu, Henry J. Curran, S. Mani Sarathy, Aamir Farooq
Summary: This study investigates the impact of exhaust gas recirculation (EGR) and NOx on the ignition delay time of oxygenated gasoline. A gasoline surrogate model is developed and the experimental data are useful for predicting fuel ignition behavior in internal combustion engines. The results show that EGR inhibits gasoline reactivity, while NOx has a promoting effect at high temperatures. This research is important for understanding the combustion behavior of gasoline in engines.
COMBUSTION AND FLAME
(2024)
Article
Thermodynamics
Chengcheng Ao, Jia Yan, Tong Yan, Lidong Zhang, Pan Wang
Summary: This study investigates the inhibitory effect of ammonia blended with hydrocarbon fuels on soot formation. The results show that there is a chemical interaction between ammonia and polycyclic aromatic hydrocarbons (PAHs), blocking the formation of larger PAHs.
COMBUSTION AND FLAME
(2024)