Browse Topic: Methanol

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Experimental Investigation on Unburned Methanol and Formaldehyde Emissions from a Direct-Injection Diesel / Methanol Dual-Fuel Engine2026-99-1646To be published on 07/24/2026
For large-bore marine methanol / diesel dual-fuel engines, this study investigates the formation characteristics of unregulated emissions through experimental methods and explores the mechanisms by which engine load and injection timing influence the emissions of unburned methanol and formaldehyde. The study was carried out on a supercharged intercooled inline six-cylinder engine, and Fourier Transform Infrared Spectroscopy (FTIR) was used to monitor the exhaust composition in real time. The study shows that methanol released in the exhaust is due to the incomplete combustion of the methanol fuel. In the combustion process of methanol fuel, formaldehyde mainly arises from two pathways, the first of which is the partial oxidation of methanol inside the cylinder; secondly, the unburned methanol in the exhaust gas oxidizes in the exhaust pipe to generate formaldehyde. As the load increased from 25% to 100%, the unburned methanol emissions decreased by 29%, and formaldehyde emissions decreased by 71%. This is mainly attributed to the enhanced oxidation reaction and reduced wall crevice effect due to the increased combustion temperature. Methanol injection timing optimization was effective in controlling unregulated emissions, with methanol emissions lower at -7° CA ATDC and formaldehyde emissions reaching larger values under this condition. Delaying the diesel injection to -16°CA ATDC led to a 38% increase in unburned methanol emissions, caused by fuel spray interactions and longer stagnation, whereas formaldehyde emissions showed minimal change.
Jiang, Yuqi, Li, Hongmei, Zhang, Wenzheng, Li, Xiao, Zheng, Liang, Meng, Yangqian, Gu, Xianan, Hua, Hanqing
Study on Diesel-Methanol Non-Premixed Combustion Characteristics of a Marine Dual-Fuel Engine at Different Methanol Substitution Rate2026-99-05177/10/2026
Methanol use in marine engines has the potential to reduce nitrogen oxide emissions, particulates, and greenhouse gas emissions. A turbocharged four-stroke marine diesel powerplant was converted to run as a double-DI (direct injection) diesel-methanol hybrid engine. Experimental studies using a non-premixed combustion scheme showed that higher methanol substitution ratios (MSR) led to increased peak heat release rates. The combustion process displayed distinctive two-phase behaviors. Increasing MSR caused retarded ignition timing, shortened combustion duration, and improved thermal efficiency. Combustion stability was significantly improved at higher MSR. Emissions results showed NOX and HC were increased in proportion to MSR, whilst particulate emissions and CO concentrations were inversely reduced. Methanol enrichment was found to enhance NOX and HC formation processes but also accelerate soot particulate decomposition and CO oxidation mechanisms.
Li, Xiao, Jiang, Yuqi, Yan, Ping, Zheng, Liang, Li, Hongmei, Zhang, Wenzheng, Chen, Chao, Man, Zhongguo
Alcohol-Based Energy Carriers in Transportation: Status, Standards, and Outlook2026-37-00426/9/2026
The global transport sector accounts for approximately 30 % of total final energy consumption and 15.9 % of worldwide greenhouse gas (GHG) emissions, with road transport alone accounting for the largest share at 11.8 %. Decarbonizing this sector requires energy sources that combine scalable generation from renewable sources with compatibility with various modes of transportation and existing infrastructure. Methanol and ethanol emerge as promising alternative energy carriers that can leverage existing logistics infrastructure while reducing dependence on fossil fuels. Global methanol production reached 112 million metric tons, and global ethanol production totaled approximately 93.5 million metric tons in 2024, compared to more than 2 billion metric tons of gasoline and diesel produced annually. The review assesses production pathways and cost trajectories for both alcohols, evaluates fuel requirements across multiple transport modes, including passenger vehicles, light- and heavy-duty vehicles, maritime shipping, aviation, and rail, and provides regulatory frameworks governing fuel standards in six major markets, the European Union, the USA, Brazil, China, Japan, and India. From a technical perspective, the internal combustion engine is examined in greater detail as the energy conversion system, synthesizing current combustion research on engine performance, emissions characteristics, and cold-start behavior. Current standards predominantly accommodate ethanol blending for spark-ignition (SI) engines in passenger vehicle applications, with permitted concentration limits ranging from 3 % in Japan to nearly pure ethanol in Brazil. Methanol applications remain more limited in road applications. In the maritime sector, recent ISO 8217:2024 specifications and International Maritime Organization (IMO) interim guidelines have established frameworks for the use of methanol and ethanol as marine fuels. Aviation remains the most restrictive sector, with alcohol fuels explicitly prohibited in certified aviation fuels due to material compatibility and safety concerns. To unlock the decarbonization potential of methanol and ethanol in the transport sector, coordinated policy support and continued technological innovation will be essential. As production scales and regulatory frameworks mature, both alcohol fuels may play an increasingly central role in the transition toward sustainable mobility.
Fitz, Patrick, Fellner, Felix, Rößlhuemer, Raphael, Härtl, Martin, Jaensch, Malte
Effect of Injector Tip Temperature on Methanol Spray Dynamics during Cold-Start Conditions2026-01-03404/7/2026
Methanol is one of the most readily produced e-fuels and remains in liquid form at ambient conditions, making storage and transportation relatively simple. In the marine sector, methanol has already been actively adopted as a pathway toward carbon neutrality. For automotive sectors, methanol offers significant potential for carbon emission reduction owing to its higher octane number and lower carbon content compared with gasoline. However, its high latent heat of vaporization and low vapor pressure suppress evaporation at low ambient temperatures, leading to increased emissions during cold-start operation. To address this issue, previous studies have explored heating the injector tip or fuel rail to enhance evaporation and atomization. The present study focuses on visualizing and quantifying the improvement in methanol evaporation characteristics under cold-start conditions by applying controlled heating to the injector tip. Experiments were conducted in a constant-volume chamber where the ambient temperature was carefully regulated, while a laterally mounted injector tip was subjected to different heating levels. Extinction images were acquired to determine spatial and temporal liquid volume fraction and to visualize spray morphology and penetration behavior for both methanol and gasoline surrogate fuel E00. Moreover, three-dimensional tomography reconstructed from extinction images taken at multiple viewing angles provided an in-depth assessment of methanol spray structure, droplet distribution, and evaporation behavior with varying injector tip temperatures under simulated cold-start conditions. These findings highlight the crucial role of injector thermal management in improving methanol-fueled engine performance during low-temperature operation.
Lee, Seungwon, Kim, Hyunsoo, Bae, Sumin, Hwang, Joonsik, Bae, Choongsik
Achieving Euro 7 WHSC NOx Emission Targets from a Spark Ignited Engine Using Methanol-Hydrogen Co-Fuelling2026-01-03214/7/2026
E-methanol is increasingly seen as a promising clean fuel because its chemical makeup is close to fossil fuels, making it easier to use in existing engines. It offers a carbon-neutral option to help reduce greenhouse gases in sectors where cutting emissions is especially difficult, such as transportation. However, while e-methanol avoids adding new carbon dioxide, burning it in internal combustion engines still releases harmful gases like oxides of nitrogen (NOx) and other toxic by-products like formaldehyde and formic acid that damage both health and the environment. This report explores a new strategy that combines methanol with hydrogen to run engines under “ultra-lean” conditions and its impact on emissions, performance and efficiency. Experiments were carried out on a single-cylinder spark ignition engine, with directly injected methanol and port fuelled injection of hydrogen. The findings show that adding about 10% hydrogen (energy basis) at low engine loads can extend the lean limit from air-fuel equivalence ratio (λ) of 1.7 to 2. This change cut NOx emissions by 99% and reduced formaldehyde emissions by 18% compared to pure methanol operation at stoichiometric. Furthermore, the NOx emissions were reduced sufficiently that engine could operate within Euro 7 World Harmonic Stationary Cycle (WHSC) limits.
Ambalakatte, Ajith, Geng, Sikai, Cairns, Alasdair, Varaei, Amirata, Harrington, Anthony, Hall, Jonathan, Bassett, Mike, Cracknell, Roger
Challenges of Mixture Formation in Methanol Port Fuel Injection Engines2026-01-03374/7/2026
Port fuel injection (PFI) is an attractive strategy for methanol adoption in both spark-ignition and dual-fuel compression-ignition engines due to its lower cost and simpler hardware compared to direct-injection. However, methanol PFI mixture formation can be challenging due to methanol’s high heat of vaporization, low volatility at cold conditions and high tendency to wall wetting. Understanding and addressing these challenges is critical to ensure robust engine operation. In this study, the effects of injector geometry, coolant temperature, intake temperature and fueling rate on mixture formation of methanol PFI have been investigated for anhydrous methanol and for a blend of 90%vol methanol plus 10%vol water in an optical engine. Mie scattering and infrared imaging were applied to assess the liquid and vapor methanol distribution in the cylinder. For a high-flow injector compatible with methanol, significant amounts of liquid were detected in the cylinder at all conditions tested, leading to poor mixing and high fuel stratification during the compression stroke. This effect was mitigated by using a multi-hole injector that promoted better atomization, indicating that high atomization is preferred over high flow for methanol PFI. The probability of detecting liquid in the cylinder decreased as the coolant temperature or the intake temperature increased or if the fueling rate decreased, with coolant temperature being the dominant parameter to control methanol vaporization. Liquid probability increased with water addition mainly because of the high heat capacity of water. Liquid methanol accumulated in the intake port, decreasing the effective engine intake temperature and limiting fuel vaporization. This accumulation led to a delay of the system response to changes in the PFI settings, with injected fuel requiring one cycle to reach the cylinder and additional 50 cycles required to completely flush the fuel accumulated in the port. Finally, the operating envelope for liquid-free operation was defined.
Lee, Sanguk, Narayanan, Abhinandhan
Methanol Mixing Controlled Combustion Process Enabled by Methanol Dehydration to Dimethyl Ether2026-01-03224/7/2026
This work demonstrates an initial proof-of-concept approach for operating a compression ignition off-road and marine relevant engine using neat methanol. The approach utilizes mixing controlled compression ignition (MCCI) of methanol that is enabled by a homogeneous charge compression ignition (HCCI) pre-burn of premixed dimethyl ether (DME). Although two fuels are used, this work explores and evaluates the opportunity and performance to generate the premixed fuel via methanol catalytic dehydration over an alumina catalyst at engine relevant temperatures, pressures, and space velocities. Conversion purity and species output results from catalytic dehydration bench flow reactor studies were coupled with single-cylinder experiments of the characterized output species for pre-burn HCCI performance. Subsequently, methanol MCCI performance is also evaluated and compared to conventional diesel combustion. The detailed flow reactor results show that the catalytic dehydration conversion efficiency of methanol to DME is a function of system pressure, temperature, and space velocity. The engine results demonstrate that a 100% conversion of methanol to DME is not required for successful pre-burn HCCI, and the water formed during the dehydration process does not need to be removed to achieve the desired HCCI event from this pre-burn mixture. Subsequent methanol MCCI combustion results show that the level of methanol slip in the dehydration process affects the pre-burn HCCI phasing, low temperature heat release process, and magnitude of energy release, all of which can dictate the available window for direct-injection of methanol for MCCI combustion. 1
Jatana, Gurneesh, Splitter, Derek, Park, Yeonshil, Szybist, James, Svensson, Kenth, Montgomery, David
Effect of Pre-Chamber Geometry on Methanol Cold-Start Combustion in an SI Engine2026-01-03074/7/2026
Vehicle pollutant emissions are a major challenge in the development of internal combustion engines. To meet increasingly strict regulations, the automotive sector is exploring alternative fuels and lean-burn strategies. Methanol is gaining importance as a carbon-neutral fuel due to advances in green production technologies. Methanol, despite its potential for renewable production, faces severe limitations due to its inherent poor cold-start performance with conventional ignition systems. In this context, the present study aims to investigate the influence of pre-chamber ignition on cold-start combustion by using high-speed optical diagnostics to visualize flame propagation while simultaneously measuring in-cylinder pressure and engine performance. A major result concerns the significant cyclic variability of conventional spark ignition (SI) under cold-start conditions, which exhibits significant cyclic variability. Instead, passive pre-chamber ignition significantly enhances cold-start combustion stability, lowering CoV IMEP to below 3% at λ = 1.0 and sustaining stability under 5% even in ultra-lean conditions (λ = 1.6), where conventional SI operation fails. Flame visualization quantitatively confirms that this stability stems from distributed, multi-point ignition, which accelerates initial flame propagation by 3-4x compared to SI. These findings demonstrate that pre-chamber ignition can effectively overcome the traditional "cold-start" problem for methanol, enabling stable combustion from the first cycles. This provides an invaluable dataset for CFD model validation, as it captures a highly stable combustion process largely independent of the adverse thermal boundary conditions typical of cold start, thereby simplifying the modeling challenge.
Sementa, Paolo, Altieri, Nunzio, Tornatore, Cinzia
Rolls-Royce pursues pure methanol for marine engines26TOFHP02_052/1/2026
Rolls-Royce has successfully tested the world's first high-speed marine engine powered exclusively by methanol on its test bench in Friedrichshafen, Germany. The company began this engine-development journey six years ago when it gathered experts to determine what the future fuel of the maritime industry should be, according to Denise Kurtulus, senior vice president of global marine at Rolls-Royce. “For us, it's clear. It's methanol,” she said. Rolls-Royce worked with industry partners as part of the joint project meOHmare, which is funded by the German Federal Ministry for Economic Affairs and Energy. Injection system specialist Woodward L'Orange and the WTZ Roßlau technology and research center contributed their expertise. Their goal was to not only develop a comprehensive concept for a CO2-neutral marine engine based on green methanol, but also to run it on the test bench by the end of 2025.
Gehm, Ryan
Performance Analysis of Methanol- Ethanol Blend Fuel in a Spark-Ignition Flex-Fuel Engine2025-36-014812/18/2025
Flex-fueled vehicles (FFV) dominate the Brazilian market, accounting for over 75% of the national fleet. Ethanol fuel is widely used, primarily in the form of hydrated ethyl alcohol fuel (HEAF). Given the similar physicochemical properties of ethanol and methanol, fuel adulteration is a growing concern, often involving the addition of anhydrous ethanol, methanol, or even water to hydrated ethanol. These adulterants are visually imperceptible and can only be detected through analyses conducted by regulatory agencies using specialized instruments. However, they can significantly affect vehicle performance and accelerate engine component deterioration. The experiment was performed with a small displacement 3-cylinder port fuel injection flex-fuel engine on an engine test bench (dynamometer) and compared when fueled with ethanol and methanol. Data acquisition included combustion pressure, spark plug temperature, torque, air-fuel ratio, fuel flow, spark maps, and the overall effects of methanol adulteration on combustion. The results indicate that engines designed and calibrated to operate with hydrated ethanol exhibit different combustion behaviors when methanol is present in the fuel mixture. Methanol increases combustion pressure and temperature inside the chamber, creating a highly corrosive environment due to both the elevated temperature and the chemical properties of methanol. Fuel consumption increased when methanol was used in the engine calibrated for ethanol. The findings highlight the potential risks associated with fuel adulteration, emphasizing its impact on engine durability, vehicle fuel economy, and maintenance costs.
Mascarenhas, Giovana Rebellato, Gomes, Ederson, Cruz, Diego, Duque, Edson Luciano
Biodiesel Production via Homogeneous Route (KOH) and Heterogeneous Route (K 2 O/Nb 2 O 5 )2025-36-011612/18/2025
Biodiesel, a renewable biofuel obtained from vegetable oils or animal fats, has emerged as a sustainable alternative to fossil fuels. This fuel has stood out for its ability to reduce greenhouse gas emissions, helping to mitigate environmental impacts. Biodiesel is produced by reacting oil with an alcohol in the presence of a catalyst, which can be homogeneous or heterogeneous. Heterogeneous catalysis has advantages such as ease of separation, greater tolerance to oils with a high fatty acid content and the possibility of reusing the catalyst, which reduces costs and minimizes waste generation. Among the various heterogeneous catalysts available, niobium-based compounds stand out. The use of niobium-based catalysts is advantageous due to the vast reserves of this element in Brazil, guaranteeing autonomy in production and strengthening the national biofuels industry. This work investigated the production of biodiesel from soybean oil using the homogeneous and heterogeneous transesterification routes. The homogeneous route used 0.7% KOH dissolved in methanol, operating at 60 °C for 1 hour with a methanol:oil molar ratio of 6:1. The heterogeneous route used a solid K2O catalyst supported on Nb2O5, in a ratio of 4% by mass, with a molar ratio of 10:1 and a reaction time of 4 hours. The yield obtained was 85% for the homogeneous route and 90% for the heterogeneous route. The biodiesel from the homogeneous route had a slightly basic pH, requiring neutralization with hydrochloric acid, while the product from the heterogeneous route had a neutral pH, requiring no additional treatment. The results indicate that although the homogeneous route is faster and uses less catalyst, the heterogeneous route has advantages in terms of yield and quality of the final product, as well as less environmental impact. Heterogeneous catalysts such as K2O/Nb2O5 are therefore promising for the sustainable production of biodiesel.
Coelho, Gabriella Vilela, Alvarez, Carlos Eduardo Castilla, Ribeiro, Jessica Oliveira Notório
Experimental Investigations on Lean Burn Spark-Ignition Engine Using Alcohol-Gasoline Blends2025-28-021311/6/2025
Alcohol fuels are regarded as a feasible approach to address rising energy demands and reduce the dependency on fossil fuels, with ethanol and methanol emerging as a promising renewable fuel for spark-ignition engines. In this research work, tests were performed on a spark ignition engine altered from a diesel engine that employs ethanol/methanol-gasoline blend as fuel operating under lean conditions. The experiments were conducted at 10.5:1 compression ratio and 1500 rpm under full throttle condition with three fuel blends namely M10 (10% of methanol+ 90% gasoline), E10 (10% of ethanol+ 90% gasoline), E5M5 (5% of each ethanol and methanol+ 90% gasoline). Investigational results reveals that alcohol-gasoline blends displayed low COV of IMEP. Furthermore, the alcohol-gasoline mixtures enhanced the peak in-cylinder pressure owing to improved flame speed and flammability limits. Adopting lean-burn operation and high compression ratio can efficiently improve combustion attributes in an alcohol-gasoline fuel operated spark ignition engine.
Devunuri, Suresh, Porpatham, Dr. E
Study of Combustion Characteristics of a Two-Stroke Opposed Piston Engine using Low-Octane Fuels2025-32-002811/3/2025
Various fuels are being considered as the next generation of carbon neutral fuels, including methanol, ethanol, and SAF. These have widely different ignition properties. Methanol and ethanol are high-octane fuels, so there are no major problems with their use in gasoline engines. However, SAF is a hydrocarbon with a large molecular weight, so it has a fundamentally low octane rating and is not easy to use in SI engines. In order to put carbon-neutral fuels of various properties into practical use, it is effective to develop a technology that allows fuels with low octane to be operated in SI engines. Therefore, in this study, basic research was conducted on the combustion of fuels with low octane using PRF fuel in opposed-piston engines. Opposed piston engines are characterized by their light weight due to the absence of a cylinder head, low S/V ratio due to the ultra-long stroke, reduced cooling loss due to the long stroke, and reduced vibration due to the offsetting of the reciprocating inertial forces of the left and right pistons, resulting in high efficiency and output. In addition, one of the disadvantages of low-octane fuel is that it tends to auto-ignite, but combustion under high residual gas conditions has the effect of suppressing fuel auto-ignition, and by using a 2-stroke engine with a high percentage and high concentration of residual gas and locally high temperatures, auto-ignition is suppressed and low The use of two-stroke engines with high residual gas content and high concentration and high local temperatures can be expected to suppress auto-ignition and allow the use of low-octane fuels.
Yamazaki, Yoshiaki, Okawara, Ikumi, Liu, Jinru, Iijima, Akira
Computational Investigation on a Boosted Uniflow Scavenged Direct-Injection Combustion Engine (BUSDICE) with Alcohol Fuels2025-32-002711/3/2025
Alcohol fuels, produced from renewable energy sources, are considered a crucial solution for achieving life-cycle carbon neutrality in internal combustion engines. The Boosted Uniflow Scavenged Direct-Injection Combustion Engine (BUSDICE) exhibits significant potential for high thermal efficiency with an aggressive downsizing design. In this study, a computational investigation was carried out to assess the spray mixing and combustion characteristics of BUSDICE fuelled with methanol and ethanol, compared with gasoline, under a high-load condition. The injection duration of methanol and ethanol is significantly longer than that of iso-octane, leading to incomplete evaporation. The mixture exhibits an “outer-rich, central-lean” stratification pattern due to the short mixing time and swirl flow transportation for all three fuels. However, the prolonged injection of methanol induces stronger turbulence, which can enhance the local mixing. The spatial mixture stratification, particularly near the spark-local area, has a strong influence on the initial kernel development and flame propagation. Consequently, methanol exhibits a shorter ignition delay than ethanol under the same spark timing, leading to faster flame propagation attributed to a richer equivalence ratio around the spark plug. Nevertheless, the ignition and combustion performance of ethanol can be improved by advancing the spark timing. The spark timing study reveals that alcohol fuels can operate under high load without knocking, whereas iso-octane requires retarded ignition timing to prevent knocking. As a result, methanol and ethanol provide a better IMEP and ITE than iso-octane under high-load conditions. From an emissions perspective, due to their low carbon-to-hydrogen (C/H) ratio and high oxygen content, unburnt hydrocarbon emissions decrease significantly when using alcohol fuels, especially methanol, for which these emissions are almost zero. However, the soot of ethanol shows a slight increase than iso-octane, due to the highly stratified mixture and incomplete combustion. Additionally, the NOx of ethanol and methanol increases due to the higher combustion temperatures than iso-octane. Overall, the results highlight the strong potential of alcohol-fuelled BUSDICE engines as compact and sustainable solutions for small-displacement powertrains, offering high thermal efficiency and substantially reduced pollutant emissions.
Feng, Yizhuo, Lu, Enshen, Dong, Shuo, Keshtkar, Hossein, Wang, Xinyan, Zhao, Hua
Methanol Cold Start Procedure for a Serial Hybrid Powertrain2025-24-00749/7/2025
Methanol obtained from regenerative sources is a renewable fuel with many advantages when used in a spark ignition combustion process. Methanol has a comparatively high enthalpy of vaporization, leading to lower combustion temperatures (compared to gasoline combustion) and, hence, lower wall heat losses as well as a reduced tendency to autoignition. Several cold start methods were examined for this paper. In a serial hybrid powertrain with one internal combustion engine, ICE, and one electric machine, the load demand of the ICE can be controlled for best efficiency. The ICE is operated on liquid renewable fuel, which provides a high volumetric and gravimetric power density, easy energy storage, delivered from a very cost effective already existing infrastructure of fuel distribution. The electric machine provides comfortable electric driving, high efficiency, locally and temporary zero emissions. The eFuel should be produced from a closed carbon cycle. Methanol is a challenging fuel, since it has a high flash point at 11 °C indicating a challenging cold start. Feasible solutions are fuel or intake air heating or blending with lightly boiling components. All of these incur expenses for additional component and processes. One of the cold start procedures presented in this paper enables the cold start of pure methanol down to –20 °C, without the necessity for additional engine components. For this the serial hybrid propulsion system is used. The electric machine was used to motor the ICE at high engine speeds and strongly throttled with minimal fuel mass, to allow for fuel evaporation in the intake and heating during the compression stroke. A 3D-CFD simulation was setup the explore the procedure. The new procedure is compared to a conventional process with air and fuel heating.
Dobberkau, Maximilian, Werner, Ronny, Atzler, Frank
Mid-IR Laser Extinction Measurements of Formaldehyde Emissions in a Methanol Mixing-Controlled Compression Ignition Engine2025-24-00349/7/2025
As energy security and sustainability becomes important, the role of alternative fuels, particularly methanol, is becoming increasingly significant. While the feasibility of methanol as a substitute for diesel fuel has been explored, understanding of emissions from methanol-fueled compression-ignition engines remains limited, even though these engines are known to emit formaldehyde (CH2O) due to methanol’s chemical structure and oxidation pathways. In this study, a quantitatively measurable mid-IR laser-based extinction methodology was employed to understand CH2O formation in a methanol mixing-controlled compression ignition (MCCI) engine. Stable methanol MCCI combustion was achieved with the addition of 5%vol 2-ethylhexly nitrate (EHN) and by using a triple injection strategy (pilot + pilot + main), and CH2O emissions were measured with high temporal resolution by laser extinction while sweeping the injection timing. In addition, the injection strategy was systematically varied by enabling and disabling different injection events to investigate the effect of pilot and main injections on CH2O formation. Injection timing sweeps revealed that CH2O emissions did not monotonically increase with retarded injection, as carbon monoxide did. This decoupling suggests that CH2O formation is not governed solely by global combustion inefficiencies but is instead tied to localized mixture conditions and oxidation pathways. Cycles with elevated CH2O emissions featured minimal low-temperature heat release of pilot injections and, subsequently, more retarded combustion phasing. This indicates that combustion quality of pilot injections strongly affect engine-out emissions, and suggests that overly lean mixtures created by pilot injections promote CH2O formation when later exposed to high-temperature heat release (HTHR). Injection strategy modulation showed that the absence of HTHR results in minimal CH2O emissions, even when large amount of fuel were injected, emphasizing HTHR’s role in initiating methanol oxidation and CH2O formation. In contrast, strategies promoting lean mixtures followed by HTHR led to higher CH2O emissions due to incomplete oxidations. Additionally, acetaldehyde (CH3CHO) emissions were consistently detected. Chemical kinetic simulations revealed that CH3CHO forms through unimolecular decomposition of EHN-derived intermediates or secondary reactions between methanol and species derived from EHN oxidation like C2H5O2. These results offer new insight into the oxidation behavior of methanol under MCCI conditions and highlight the role of thermal and chemical stratification in pollutant formation.
Lee, Sanguk, Lopez Pintor, Dario, Narayanan, Abhinandhan
Optimization of the Injection Strategy to Enhance Mixture Formation in a 4-Cylinder Methanol Engine by Means of a 3D-CFD Virtual Engine Test Bench2025-24-00779/7/2025
Emissions reduction and carbon neutrality are two obligations to fulfil in order to ensure a clean and bearable planet for the future. The diversification of energy carriers is one of the keys to achieving a concrete and time-effective solution, and methanol can be one of the possible ways to reach carbon neutrality, showing many positive characteristics to be used as fuel for internal combustion engines (ICEs). Using methanol as a fuel or in a blend can greatly reduce exhaust gases composition, with a great impact on CO2 emissions. Nevertheless, some challenges have to be overcome to exploit the whole potential of methanol as a fuel. The aim of this work is to investigate which aspects can improve the mixture formation using a 4-cylinder gasoline engine fuelled with methanol. The study was conducted numerically, by means of a virtual engine test bench, considering two different operating points, the former at high engine speed and load, the latter in a lower load region of the engine map. As first step, the injection model has been validated with experimental data acquired employing methanol spray analysis which has included spray geometrical features and droplet size measurements. 3D-CFD simulations analysis of different injection methods have been conducted, to understand which parameters affect methanol mixture formation more. Two different injector temperatures are used, showing considerable differences in terms of combustion efficiency and knock onset. As a second step, a PFI injector mounted in the intake channel has been considered as a replacement for the direct injector to exploit methanol intake charge cooling power and increase volumetric and indicated efficiency. The results of these analyses are presented in this work, discussing methanol performances compared to a commercial SP98 gasoline, showing how an optimized methanol injection strategy can improve efficiency and enlarge the range for lean operations.
Tortorella, Cristian, Rossi, Edoardo, Vacca, Antonino, Chiodi, Marco, Kulzer, Andre Casal
Effects of Piston Pre-Heating and Friction Reduction on Cold-Start Charge Preparation for DI Methanol Engine: An In-Cylinder CFD Study2025-24-00409/7/2025
Methanol is gaining interest as a renewable fuel for Internal Combustion Engine (ICE) applications. A key challenge for this fuel is its low evaporation rate at low temperatures, which makes cold-starts problematic, particularly in cold climate conditions. The first combustion cycles are characterized by a low combustion chamber temperature and high engine friction. In previous work by the authors, a practical approach was presented to pre-heat the pistons and pre-condition the bearings, thereby reducing friction. In this article, in-cylinder Computational Fluid Dynamics (CFD) modeling is used to study the charge preparation of a DI-SI methanol ICE up to the end of compression. The model is calibrated in-house using measurements from a warm methanol engine. The piston temperature is varied within the range expected from the pre-heating and pre-lubricating device. Friction reduction is translated into the reduced amount of fuel needed to generate the IMEP required to idle the engine. Engine starting conditions at -20°C, 0°C, and +20°C are simulated. For these global conditions, different combinations of piston pre-heating and friction reduction are investigated. Warm engine conditions (90°C) are also modeled for comparison. The results show that the piston is a primary target for fuel spray. As expected, for a warm engine, the injected fuel is completely evaporated. For an ordinary cold-start at 20°C, the fuel distribution at the end of compression is 81% evaporated, 15% remains as film, and the rest as suspended droplets. In the cold-start at -20°C, only 23% of the fuel is evaporated at the end of compression, while the majority is deposited as a fuel film. By pre-heating the piston alone, the evaporated fuel increases to 37%. Alternatively, reducing the friction load to match warm engine conditions, drastically reduces the total fuel injected, resulting in 59% evaporated fuel. This demonstrates the potential of the proposed technology to improve methanol cold-start emissions.
Bovo, Mirko, Mubarak Ali, Mohammed Jaasim
Lignin as Cetane Booster for Methanol and Ethanol2025-24-00759/7/2025
Low carbon, though poorly igniting (i.e., low cetane) fuels, such as methanol, ethanol, and ammonia, are gaining momentum in the maritime fuel market. The most adopted strategy to address the fact that these fuels will not, under typical two-stroke marine engine conditions, auto-ignite, is to co-inject a pilot fuel, such as (very) low sulfur marine fuel oil, which does auto-ignite and furthermore doubles as a spark of sorts for the poorly igniting base fuel. This so-called dual-fuel approach is costly and cumbersome. Cetane boosters are known to improve ignitability of alcohol fuels to the point that a pilot fuel is no longer required. In our earlier research, we found some indication that lignin model compounds could likewise improve the ignitability of alcohols. This paper builds further on this hypothesis, now using commercially available lignin rather than model compounds. Auto-ignition behavior of methanol and ethanol was investigated with up to 10 wt% of therein solubilized lignin in both an Advanced Fuel Ignition Delay Analyzer (AFIDA) and (two-stroke) spray combustion chamber. The results suggest that lignin indeed improves the ignitability of both alcohols and that pilotless auto-ignition is possible under realistic two-stroke marine engine conditions when 10% of (alcohol-soluble) lignin is blended into ethanol, with the associated cetane number being close to 10.
Sementa, Paolo, Tornatore, Cinzia, Catapano, Francesco, Lazzaro, Maurizio, Iannuzzi, Stefano, Kouris, Panos, Boot, Michael
Spray Dynamics and Collapsing Process of Methanol in a Lateral-Cylinder-Mounted DI Injector2025-24-00639/7/2025
The morphology and collapsing behavior of fuel sprays play a critical role in determining atomization and vaporization characteristics, directly influencing combustion efficiency and emission formation in direct injection systems. In this study, spray dynamics and collapsing processes of methanol and gasoline fuels were examined using a lateral-cylinder-mounted direct injection (DI) injector in a constant volume combustion chamber (CVCC). A tomographic imaging technique was applied to analyze the spatial and temporal characteristics of fuel sprays. Extinction imaging was performed to capture the distribution of droplets within the spray, and the liquid volume fraction (LVF) was quantified based on the Beer-Lambert law. By acquiring extinction images from multiple viewing angles, 3D tomographic reconstructions of the spray morphology were achieved, providing detailed insights into the structural evolution of the sprays during injection. The high latent heat of vaporization of methanol significantly influences the spray morphology and plume dynamics, potentially resulting in distinct behaviors compared to gasoline under identical injection conditions. These differences are expected to manifest in the droplet evaporation rates, plume expansion patterns, and overall spray stability. The 3D tomographic reconstruction method provides a detailed visualization of these phenomena, offering valuable insights into how methanol’s thermophysical properties impact spray characteristics and plume collapse tendencies. This research highlights how methanol’s unique properties influence spray behavior, paving the way for optimized injection strategies and alternative fuel integration. These findings can serve as a foundation for future studies exploring the adaptation of direct injection systems to sustainable fuel applications.
Kim, Hyunsoo, Lee, Seungwon, Bae, Sumin, Hwang, Joonsik, Bae, Choongsik
Influence of Fuel Surface Tension and Viscosity on Internal Flow Bubble Formation and Atomization in Flash Boiling Sprays2025-01-02216/16/2025
Flash boiling atomization is considered a promising atomization technique for combustion applications in automotive powertrains. It can potentially address the deteriorated atomization issue for alternative fuels (such as methanol) in internal combustion engines. However, it has been observed that flash boiling spray atomization for methanol fuels is not as effective as that for traditional alkane-based fuels. This work aims to explain such phenomena using transparent nozzles to reveal the impact of internal vaporization on external spray breakups. Three different working fluids, including methanol, ethanol, and pentane, are tested with elevated temperatures. The flow patterns and external liquid breakup are shown with the high-speed imaging technique. It is found that the internal phase change of the base working fluid is suppressed when ethanol or methanol is used instead of pentane. Consequently, the external liquid breakup is also hindered due to insufficient vapor phase inside the nozzle. It is held that increased surface tension and viscosity have made the nucleation process more challenging compared with typical gasoline fuels.
Zhang, Yijia, Li, Yilong, Wang, Shangning, Zeng, Tingxi, Xu, Min, Hung, David, Li, Xuesong
An Experimental and Numerical Study of Ultra-Lean Combustion Characteristics of Methanol Direct Injection using Various Coil Spark Ignition Strategies2025-01-02006/16/2025
Methanol is significantly emerging as a promising alternative fuel in the pursuit of carbon neutrality. This study aims to analyze the combustion characteristics of methanol in a spark-ignition (SI) engine operating under high compression ratios and ultra-lean conditions through both experimental and simulation approaches. The objective is to derive optimized combustion efficiency by employing various ignition strategies based on discharge energy. To this end, experiments were conducted using a Rapid Compression Expansion Machine (RCEM) to replicate realistic engine environments. The effects of discharge energy and spark duration across different spark coil configurations were investigated through both experimental methods and computational fluid dynamics (CFD) simulations. The experimental results showed that the use of multiple spark coils achieved an energy release rate of approximately 239 mJ/s, more than twice that of the single-coil configuration. Simulation results were in good agreement with the experimental findings. In the single-coil setup, combustion indicators such as in-cylinder pressure were significantly influenced by variations in spark duration. In contrast, the multi-coil configuration demonstrated higher peak values in several combustion characteristics, but once a certain threshold of discharge energy was exceeded, the improvements in performance became marginal. This suggests that simply increasing the spark duration is not always an effective strategy for optimizing the spark channel in methanol SI engines. Furthermore, the multi-coil ignition strategy significantly reduced the ignition delay, contributing to improved combustion stability under lean-burn conditions. As a result, the multi-coil strategy achieved an indicated thermal efficiency (ITE) approximately 10% higher than that of the single-coil approach, with the maximum efficiency observed at 30.4% in the 10-coil strategy.
Choi, Jeongyeon, Lim, Ocktaeck
Techno-Economic Analysis of an Integrated E-Methanol Production Plant Utilizing First and Second Generation Biomass Resources2025-01-01826/16/2025
This study presents a comprehensive techno-economic assessment (TEA) of an integrated e-methanol production system building upon previously published foundational research utilizing Aspen Plus modeling for e-methanol production from sugar cane and sugar beet biomass. The established integrated system converts biomass into ethanol through fermentation and synthesizes e-methanol using both captured CO2 and syngas derived from biomass residue gasification. This approach maximizes CO2 and biomass utilization, promoting a circular carbon economy. The TEA quantifies capital expenditures (CAPEX), operational expenditures (OPEX), and levelized costs of Methanol (LCOM), providing a detailed economic analysis of the potential for commercializing e-methanol. A sensitivity analysis evaluates the impact of feedstock prices and Technology Readiness Levels (TRL), identifying key leverage points affecting financial viability. The study aims to explore the potential of utilizing existing agricultural infrastructure for sugar cane and sugar beet to minimize setup costs and expedite market readiness. The system’s capacity to reduce carbon emissions significantly aligns with global sustainability goals. This study provides strategic recommendations for scaling e-methanol production and improving its economic viability in the renewable energy sector. The sensitivity analysis particularly aids in developing robust strategies to mitigate risks associated with economic and market fluctuations.
Fernandes, Renston Jake, Shakeel, Mohammad Raghib, Nguyen, Ducduy, Im, Hong G., Turner, James W.G.
Thermal Efficiency Improvement and Emission Reduction of Methanol Spark Ignition Engine Using Lean-Burn Strategy2025-01-02246/16/2025
Methanol is a promising fuel for achieving carbon neutrality in the transportation sector, particularly for internal combustion engine vehicles. With its high-Octane number, methanol enables higher thermal efficiency compared to gasoline engines. Additionally, its wide flammability range allows stable engine operation under lean burn conditions at low to mid-load levels. These characteristics make methanol well-suited for lean-burn strategies, which reduce pumping losses and enhance thermal efficiency. However, there remains a lack of studies on the influence of injection timing under different lean conditions, particularly in a wall-guided spark ignition engine. Wall-guided systems use the chamber wall or piston surface to redirect and stratify the fuel-air mixture near the spark plug at the time of ignition. The combustion performance of lean-burn engines in highly sensitive to variations in injection and excess air ratio. In this study, experiments were conducted on a single-cylinder engine to examine the combustion and emission characteristics under varying excess air ratios and the injection timings. At an SOI of -180 CAD aTDC, a thermal efficiency of 47.5% was achieved when the excess air ratio was increased. This corresponds to a 5.62% improvement in efficiency compared to the condition with excess air ratio (λ) 1.2 condition, representing the largest increase among all tested conditions. Due to high thermal efficiency, high vaporization heat of methanol, and low combustion temperature of lean conditions, nitrogen oxides emission decreased from 10.24 g/kWh to 2.23 g/kWh. However, corrected hydrocarbon emission increased from 3.07 g/kWh to 6.98 g/kWh under SOI -120 CAD aTDC condition, leading to the decline in combustion efficiency.
Lee, Seungwon, Kim, Hyunsoo, Hwang, Joonsik, Bae, Choongsik
Comparison of Methanol and Gasoline Fuel Spray Vaporization Using Direct-Injection Technology2025-01-02256/16/2025
Considering the large opportunity to reduce net lifecycle carbon emissions through the use of renewable methanol, we address spray technologies needed to overcome the challenge of wall wetting and poor vaporization for methanol and the need for improved computational modeling of these processes. High-speed extinction imaging followed by computed tomography reconstruction is utilized to provide three-dimensional liquid volume fraction for reference fuel injectors, to be used for model validation activities. The first injector is the symmetric 8-hole Spray M injector for the Engine Combustion Network, and the second injector is an asymmetric 6-hole injector designed for lateral-cylinder mounting. The degree of plume interaction and vaporization are characterized at representative injection conditions, showing substantially higher concentrations of liquid for methanol than gasoline even with preheated fuel temperatures (90 degrees C). In light of higher injected mass requirements for methanol sprays in combustion applications due to its lower chemical enthalpy, an elevated injection pressure is explored to visualize their effects on spray morphology and improve our understanding of the accelerated evaporation from higher injection pressure. Differences between using collimated and diffuse lighting for extinction measurements are discussed along with the uncertainties associated with each diagnostic. The collimated light source provides higher fidelity optical thickness measurements compared to the diffuse light source but suffers from interference from vapor-phase beam steering. The beam steering effects creates difficulty on the determining the liquid boundary but has negligible impact on the total measured extinction at mild conditions.
Wan, Kevin, Clemente Mallada, Rafael, Buen, Zachary, White, Logan, Oh, Heechang, Dhanji, Meghnaa, Pickett, Lyle
Morphology Experiment of Icing Effect on Spray Propagation2025-01-02226/16/2025
The working conditions of combustion systems have been going extreme under the desire of human beings exploring the unknown. Cold environments can be a significant impact on the spraying of fuel not only by changing the fuel properties including viscosity and surface tension, but also by freezing the parts. In the present study, methanol spray from a commercial injector is studied via high-speed imaging, with the liquid fuel being frozen to sub-zero degrees at the injector tip. It is observed that water components from the environment will freeze at the injector tip, creating crystal structures on the surface. During the injection, the ice components will be flushed by the liquid, and the spray morphology of the starting cycle will be strongly altered, resulting in wider spray angles, much shorter penetrations, and particle structures can be observed in the downstream of the flow field. The results of the experiment provide a clear view and quantified evaluation of the freezing impact on spray development from practical injectors, and gives a sketch of the most extreme condition of the fuel spray before the valve is chilled to the bone and unable to open.
Zeng, Tingxi, Wang, Shangning, Zhang, Yijia, Hung, David, Xu, Min
Use of Methanol in a High-Power Density Generator13-06-03-00214/2/2025
Increasing global pressure to reduce anthropogenic carbon emissions has inspired a transition from conventional petroleum-fueled internal combustion engines to alternative powertrains, including battery electric vehicles (EVs) and hybrids. Hybrids offer a promising solution for emissions reduction by addressing the limitations of pure EVs such as slow recharge and range anxiety. In a previous research endeavor, a prototype high-power density generator was meticulously designed, fabricated, and subjected to testing. This generator incorporated a compact permanent magnet brushless dynamo and a diminutive single-cylinder two-stroke engine with low-technology constructions. This prototype generated 8.5 kW of electrical power while maintaining a lightweight profile at 21 kg. This study investigates the performance and emissions reduction potential by adapting the prototype to operate on methanol fuel. Performance and emissions were experimentally evaluated under varying operating conditions. In addition, a comparative analysis between methanol fuel and conventional gasoline was performed. It was found that the generator operable on methanol achieved an overall increase in performance with a peak power output of 10 kW when compared to gasoline. In addition, the generator demonstrated significant reductions in carbon emissions. The goal of this research is to adapt and demonstrate the high-power density, low-emission electric power generator from previous work, which was suitable for applications such as, for example, range extenders and UAV propulsion, to use renewable fuel. This research showcases a potential direction for an electrical generator that offers reduced emissions in applications where specific power is critical.
Gore, Matt, Nonavinakere Vinod, Kaushik, Fang, Tiegang
Decarbonization of Off-Road Engines by Methanol Mixing-Controlled Compression Ignition with Ignition Enhancer2025-01-84114/1/2025
Methanol is one of the most promising fuels for the decarbonization of the off-road and transportation sectors. Although methanol is typically considered an alternative fuel for spark ignition engines, mixing-controlled compression ignition (MCCI) combustion is typically preferred in most off-road and medium-and heavy-duty applications due to its high reliability, durability and high-efficiency. In this paper, methanol MCCI combustion was enabled using ignition improvers and the potential benefits of this approach compared to conventional diesel combustion were investigated. Methanol was blended with 7%vol of 2-ethylhexyl nitrate (EHN) and experiments were performed in a single-cylinder production-like diesel engine with a displacement volume of 0.8315 L and a compression ratio of 16.5:1. The conditions of the ISO 8178 C1 regulatory cycle for off-road engines were tested, and performance and emissions over the cycle were calculated. Methanol MCCI shows 5.3% lower fuel consumption (in gallons of diesel equivalent) than conventional diesel combustion, resulting in a 20% reduction in operation costs. Smoke emissions are also very low, 97% lower than those of conventional diesel over the cycle, and a diesel particulate filter will not be required with methanol. CO emissions are higher than those of diesel and slightly higher than the legal limit, so an oxidation catalyst will be required with methanol. However, low load operation at rated speed accounts for 44.2% of the total CO emissions over the regulatory cycle, so optimization of this operating point is key to reduce CO and simplify the required aftertreatment. NOx emissions are higher than the legal limit for both methanol and diesel, so both technologies will require NOx aftertreatment, such as a selective catalyst reduction catalyst. In conclusion, the ultra-low soot, lower fuel consumption, lower operating cost, and retrofit potential of methanol MCCI indicate that this is a promising approach for decarbonization of the off-road sector.
Lee, Sanguk, Lopez Pintor, Dario, MacDonald, James, Narayanan, Abhinandhan, Chan, Adrian
Assessment of a Heavy-Duty Diesel Engine Retrofitted to Dual-Fuel and Neat Methanol SI Operation2025-01-84404/1/2025
This paper explores the potential of leveraging methanol's knock-resistant properties to facilitate both dual fuel (DF) and spark ignition (SI) operation in retrofitted heavy-duty (HD), high-speed marine engines. The study involves retrofitting an original 6-cylinder 7.15L CI diesel engine with port fuel injection (PFI) of methanol to enable DF operation. Later, the diesel injectors were replaced with six spark plugs allowing SI operation. Notably, efforts were made to minimize adaptations to the existing diesel engine, maintaining the compression ratio (CR) at 17.6:1 and retaining the same turbocharging pressure. This research aims to assess the feasibility of retrofitting conventional HD diesel engines (high CR, large bore) for dual-fuel and SI operation on methanol, with a focus on optimizing engine performance, while preserving key characteristics for HD applications, e.g. high torque and high power density. The high CR required spark retarding to prevent knock at higher loads in SI operation. Despite this, efficiencies comparable with diesel were obtained for both diesel-methanol dual-fuel as SI operation on 100% methanol, although differences were noticeable depending on the load. Tests were performed at 1500 rpm with a BMEP of 3.5, 7.1 and 10.6 bar, respectively 22, 44 and 66% of the maximum engine load. The maximum load achievable in stoichiometric SI operation was 12.3 bar BMEP, corresponding to 77% of the original maximum load with diesel CI. At this load, a brake thermal efficiency of 38.5% at stoichiometric conditions was attained. At lean conditions (λ=1.25) an efficiency of 40.1% was reached, with no significant difference compared to a 40.3% efficiency attained in diesel-only operation.
Dejaegere, Quinten, Ballerini, Alberto, Demiddeleer, Sheldon, Vanderbeken, Thomas, Bracke, Kwinten, Gyselinck, Ben, D'Errico, Gianluca, Verhelst, Sebastian
Application Status and Function Analysis of Methanol in Hydrogen Transportation Energy Supply2025-01-70991/31/2025
Methanol, with its abundant production, mature synthesis process, well-established storage and transportation infrastructure, and no need to return the dehydrogenated product, is considered to be an ideal hydrogen carrier, is expected to play a great role in the energy transition of the transportation sector and the construction of a hydrogen transportation system. This paper focuses on the hydrogen energy supply system using methanol as a carrier, briefly introduces the basics of methanol production and transportation, and then focuses on the different routes of using methanol in hydrogen transportation infrastructure and vehicles from the perspectives of technology, economy, safety, and commercialization process. Finally, the impacts of the different routes of introducing methanol on hydrogen transportation are compared and analyzed, and the role of methanol in the energy supply of hydrogen transportation is elaborated.
Zhao, Xinlong, Huo, Tianqing, Huang, Ye, Zheng, Huaan, Shi, Tongqiang, Zhang, Xu, Yang, Fusheng, Wu, Zhen, Zhang, Zaoxiao
Experimental Study on Combustion and Emission Characteristics of a Two-Stroke Engine applying PODE/Methanol Blends Direct Injection2025-01-71121/31/2025
In order to realize the Paris Agreement, which aims to strengthen the global response to climate change, conventional internal combustion engines (ICE) need to contribute to reducing carbon emissions and improving thermal efficiency. More importantly, in the face of energy shortages, it is urgent to search for sustainable fuels. Poly-oxymethylene dimethyl ethers (PODE) and methanol are both regard as important low-carbon, alternative fuels due to their high oxygen content. Using PODE can overcome the characteristics of methanol as a low-reactivity fuel with a low cetane number and poor ignition properties. In this study, the combustion and emission characteristics of PODE/methanol blends were investigated in a two-stroke direct injection engine. Firstly, the performance of the engine under pure PODE (P100) and PODE/methanol blends (P50) was compared. The results show that at BMEP of 0.31 MPa and injection timing of -8°CA ATDE, P50 blends have lower CO2, CO, NOX and THC emissions than P100 fuel. However, the start of combustion of P50 is delayed slightly and ITE is lower than that of P100. Then, the effect of injection timing on the performance of the P50 engine was investigated. With the delay of fuel injection timing, NOX emissions decrease, but CO2, CO, and THC emissions increase. Moreover, as the injection timing is delayed, the engine COVIMEP was reduced and combustion stability was improved. The engine indicated mean effective pressure (IMEP) reaches its maximum value of 0.441MPa at -8°CA ATDC and decreases as injection timing is delayed. However, the indicated thermal efficiency (ITE) decreases with the delay of injection timing, reaching a maximum of 41.8% at -8°CA ATDC. This study provides a theoretical foundation for adopting PODE/methanol blends in diesel engines, highlighting their potential to reduce conventional emissions while maintaining operational feasibility. Further research on varying methanol ratios and load conditions is recommended.
Dong, Pengbo, Sun, Zhuohan, Wang, Qingyang, Wang, Yang, Cui, Jingchen, Zhang, Zhenxian, Long, Wuqiang
Effects of Injection Parameters On the Evaporation, Mixing, Combustion and Emission Characteristics of a Spark Ignition Methanol Engine2025-01-71191/31/2025
The combustion performance test under different injection parameters was carried out on an inline 6-cylinder spark-ignition (SI) methanol engine, and the influence mechanism of injection parameters on methanol evaporation, mixing, combustion and emission was revealed through simulation. The results indicate that compared to the low-flow nozzle scheme (14*D0.26), when adopting the high-flow nozzle scheme (16*D0.30), the injection duration is shorter. The evaporation rate of methanol in the intake port is increased, the amount of methanol droplets and wall-attached liquid film in the cylinder is reduced, and the temperature in the cylinder is elevated. Moreover, the changes are more significant under high-load operating conditions. The change in the methanol charge rate during the intake process leads to a slightly higher inhomogeneity of the in-cylinder mixture. The relatively high temperature in the cylinder and the appropriate increase in the mixture concentration on the exhaust side are conducive to accelerating the combustion in the early and middle stages. The CA0-10 is shortened, and the CA50 is advanced, which improves the combustion performance under different loads. The brake thermal efficiency (BTE) is increased by 0.53% to 1.27%. Moreover, as the load increases, the increase in BTE becomes more significant. In terms of emission performance, adopting the 16*D0.26 nozzle scheme reduces the amount of methanol in the piston crevice, weakens the crevice effect, and reduces HC emissions by 56.3% to 68.5% under different loads. However, the relatively rich mixture in the combustion chamber on the exhaust side leads to an increase in CO emissions. In conclusion, adopting the high-flow nozzle scheme can lead to a relatively small increase in CO emissions while significantly reducing HC emissions, reducing the liquid film in the cylinder, and obtaining a relatively high BTE. Moreover, it is possible to adjust the injection phase more flexibly under high-load operating conditions.
Zhang, Zhi, Liu, Haifeng, Li, Yongzhi, Chang, Weide, Shu, Zanqiao, Ju, Chengyuan, Ratlamwala, Tahir Abdul Hussain, Yao, Mingfa
Development of an Algorithm for Identifying Fuel Blending Ratios for Methanol/Gasoline Flex-Fuel Engines2025-01-71071/31/2025
Flex-fuel vehicles play a crucial role in energy conservation and emission reduction; however, they often rely on expensive fuel identification sensors at the nozzle to accurately control the blending ratio. To reduce costs and enhance engine flexibility, this paper presents a flexible fuel proportion identification algorithm that utilizes exhaust oxygen content measured by the oxygen sensor and engine air intake data. Additionally, the algorithm incorporates air intake feedback control and λ feedback control, which adjusts both the throttle opening and fuel mass of the flex-fuel engine, ensuring optimal operating conditions at all times. A methanol-gasoline flex-fuel engine model was developed using GT-Power, and the algorithm model was implemented in Simulink software. Then, a co-simulation model of GT-Power and Simulink is established. In the GT-Power engine model, three parameters—engine speed, load, and methanol blending ratio—are set for the sweep points. The algorithm model in Simulink calculates the methanol blending ratio based on the data output from the GT-Power sweep points. Finally, the calculated blending ratio is compared with the actual blending ratio set in GT-Power to verify the accuracy of the algorithm described in this paper. Results indicate that the error in the methanol blending ratio calculated by the algorithm is less than 2%. The algorithm presented in this paper utilizes real-time simulation technology based on fully algebraic equations, resulting in high efficiency, accuracy, and sensitivity.
Qian, Pengfei, Nan, Tiantian, Luo, Weixing, Du, Yang, Wang, Long, Chen, Zhanming
AFR Adaptation Strategy Based on Lambda Sensor for a Methanol Engine2025-01-70391/31/2025
Methanol is an main type clean energy and it taken important part for the future internal combustion engine technology. The Equivalent air-fuel ratio (AFR) is very import for the engine combustion of methanol. And a lot of case the ratio between methanol and gasoline is not the constant number. There are no studies about AFR when fuel ratio is arbitrary in the currently. The AFR changes obviously if the tank was fueled with gasoline by mistake at a methanol spark ignition engine. Emission will be affected heavily at this situation because the AFR of gasoline is 2 times more than methanol. Some fuel trim adaptation error will be detected by engine controller or even the engine will stall if engine controller keep use the previous AFR to do the fuel injection control. The Investigation provide a relevant AFR adaption strategy based on lambda sensor and the fuel pipes configuration. The strategy was proved valid by some simulation cases to reduce lambda disturbance, optimize emission property and increase driving safety.
Liu, Yiqiang, Zhong, Jun, Qian, Pengfei, Qiao, Zhiwei, Zhu, Delei, Zhong, Shuanglei, Dong, Yanzhao, Yu, Xiuju
Research on Cavitation Flow Characteristics in Thermal Sensitive Future Fuel Nozzles2025-01-71081/31/2025
In order to clarify the cavitation flow characteristics in future fuel nozzles and guide the design of new nozzle structural blocks, this research work was carried out in both experimental and simulation aspects. In the experiment, it was found that under high injection pressure, methanol showed more severe cavitation than diesel. By adding frosted glass, a better light effect was achieved in the nozzle hole. It was found that the front section of the nozzle had geometric induced cavitation, the middle section had vortex cavitation, and the rear section had expanded vortex cavitation. Traditional numerical models cannot accurately calculate this phenomenon. To this end, the two-phase physical properties that change with temperature and pressure were constructed, combined with multiphase, turbulence, and energy models, CFD calculations were performed and verified based on visualization results. On this basis, a comparative analysis of the flow mechanism in future fuel and traditional diesel fuel nozzles was carried out, and the influence of injection pressure, fuel temperature, and nozzle structure on the flow characteristics in future fuel nozzles was studied. The relevant research conclusions provide theoretical guidance for the design of future fuel systems.
Zhang, Hanwen, Fan, Liyun, Li, Bo, Wei, Yunpeng, Zhang, Dianhao
Analysis of Injection Characteristics and Structural Reliability of Marine Methanol Fuel Injectors2025-01-71161/31/2025
Nowadays, the energy transition is at the most critical moment. In order to achieve the emission reduction target of ships, a form of boosting piston inside methanol fuel injector has been carried out. The physical property fluctuations and phase change of methanol under high pressure have been considered in the design phase. 1D-3D coupling method is used to comprehensively evaluate the performace of the injector. To this end, an Amesim simulation model is established to systematically study and analyze the injection characteristics. The injection performance of the injector under four typical loads are calculated, which is evaluated from the perspectives of injection quantity, injection duration, valve response, and leakage of boost components. In the nozzle block, the cavitation intensity of methanol is stronger than that of diesel. To reduce the possibility of cavitation erosion, as a consequence, a CFD model is established to optimize the structure of nozzle components. By adding rounded corners at the inlet of the nozzle to weaken cavitation intensity and improve injection stability. Furthermore, the mass flow rate of optimized nozzle can be improved by at least 30%. The equivalent stress and deformation of the nozzle and needle valve body under alternating thermal stress are calculated to ensure that they meet the design requirements(<1600MPa). The safety factor of fatigue also meets the requirements(>1.1). Through the complete design and simulation work, we can break through the problem of insufficient technical reserves of marine methanol injectors in China and assist in the development of low-carbon engines for self-owned brand.
Yang, Li, Wen, Liming, Zhang, Hanwen, Lu, Gangao, Dong, Weijie
Physicochemical Characterization and Potential Applications of Biodiesel Produced from Industrial Fish Waste2024-01-510611/22/2024
Biofuels are gaining significant global attention as renewable and alternative energy sources, produced from various materials through different extraction methods and conversion processes. Food industry generates not only substantial organic waste, presenting economic and ecological challenges but also potential opportunities for valorization. This study focuses on recovering industrial fish waste from the manufacture of canned tuna, specifically targeting non-food and abundant fish co-products such as heads, bones, skin, and viscera, which constitute nearly 50% of the fish body. The process involves several steps: oil extraction using Soxhlet extraction, purification, and conversion into biodiesel via transesterification, followed by physicochemical analysis. The experiments revealed that 32.41% of fish waste was in the liquid phase (a mixture of hexane and oil), and the extracted oil accounted for 26.56% of the total fish waste weight (from 1.012 kg of waste, approximately 268.78 g of oil was extracted, equivalent to 280.36 mL). The fatty acid composition influenced the cetane number of the biodiesel. Two types of biodiesel (methyl and ethyl esters) were produced from the extracted fish oil through transesterification with methanol or ethanol and sulfuric acid (H2SO4). The analysis showed that the produced biodiesels possess properties similar to conventional diesel, indicating their suitability for use in diesel engines. This research highlights the potential of fish waste valorization to reduce fossil fuel consumption and promote sustainable energy solutions.
Bousbaa, Hamza, NAIMA, Khatir, Lamia, Medjahed, Benramdane, Mohammed, Balasubramanian, Dhinesh, Johnson, Anish Jafrin Thilak
Parametric Study of Methanol Combustion Assisted by Glow Plug in a Low-Duty Diesel Engine2024-01-428411/5/2024
This work numerically investigated the feasibility of methanol compression ignition combustion for light-duty diesel engine applications by using a glow plug (GP) to promote ignition. A comprehensive parametric study was conducted to assess the combustion characteristics depending on the GP position, the relative angle between the GP and injector, and other initial conditions. Optimal design parameters were identified. It was demonstrated that GP can enable successful ignition and combustion of methanol at the operating conditions under study. Among the many parameters considered, the relative angle between the GP and injector was found to be one of the most critical parameters in controlling the ignition and complete combustion. Increasing intake temperature promoted combustion speed and engine performance, but excessively high intake temperatures led to higher wall heat transfer loss and lower ITE. An appropriate level of the pilot injection mass was found to increase ITE, with the minimum loss of combustion efficiency attained at a pilot mass fraction of 10%. Increasing the intake pressure further improved the engine performance, primarily owing to the reduced wall heat transfer loss. In contrast, the combustion was not significantly affected by the change in injection pressure, although slightly higher ITE was obtained at the lower injection pressure. It is expected that higher thermal efficiency is achievable with further optimization of design parameters.
Liu, Xinlei, Sim, Jaeheon, Raman, Vallinayagam, Viollet, Yoann, AlRamadan, Abdullah S., Cenker, Emre, Im, Hong G.
Methanol Combustion in Compression Ignition Engines with a Combustion Enhancer Based on Nitrates (CEN): Insights from an Experimental Study in a New One-Shot Engine (NOSE)2024-01-428111/5/2024
Because it can be produced in a green form methanol is envisioned as a potential fuel replacing conventional Diesel fuel to directly reduce greenhouse gases (GHG) impact of maritime transportation. For these reasons, Original Equipment Manufacturers (OEMs) are working to make methanol easier to use in Compression Ignition (CI) engines. While it is an easy to use substance with manageable energy content, methanol has a few drawbacks, such as: high latent heat of vaporization, high auto-ignition temperature. These drawbacks have an impact on the quality of combustion and therefore solutions have to be found and are still being studied to give methanol a Diesel like behavior. One solution is to use a pilot fuel for ignition in quantities that remain high (> 20 %). A previous study carried out at the PRISME laboratory highlighted the possibility of using a Combustion Enhancer based on Nitrates (CEN) at additive levels. Here the CEN impact in methanol is studied through the use of a New One-Shot Engine (NOSE), a high pressure, high temperature (HPHT), optically accessible vessel. Many parameters are explored: the Ignition Delay Time (IDT) by UV analysis and with photomultiplier (PM) which allow for verification, the vapor and liquid penetration by shadowgraphy technique and Diffused Back-Illumination (DBI) and the Lift-Off Length (LOL) also by Ultra-Violet analysis. As much as possible, the spray A conditions (60 bar, 900 K, injection parameters) recommended by the Engine Combustion Network (ECN) were observed. However, to be more representative of the previous study carried out on an engine, the compression temperature was increased to close to 950-1000 K. This study shows that the addition of CEN (5 % by volume) directly blended to methanol allows for a reduction of the IDT, of the LOL and a stabilization of the flame along the jet penetration. This is a fundamental study in order to start understanding the effect of the additive on methanol.
Samson, Richard, Morin, Anne-Gaelle, Foucher, Fabrice
Dual Injection Concept and Lean Burn Characteristics with Methanol on a SI-Engine2024-24-00309/18/2024
The research for sustainable alternative fuels for combustion engines was driven by the urgency to meet future emission regulation norms and mitigate climate change and dependency on fossil fuels. In this context, methanol emerges as a promising candidate due to its potential for greenhouse gas-neutral production methods and its advantageous characteristics for employment in SI engines. Adverse effects, such as elevated emissions due to incomplete combustion along with liner impingement and oil dilution as a consequence of the high injected fuel mass and the large enthalpy of vaporization, can be improved by a dual injection concept. The tests were conducted on a single-cylinder research engine derived from a common passenger vehicle engine. The exhaust gas composition was measured with an FTIR-analyzer employing a methanol-specific evaluation method, standard exhaust gas analyzers, and a solid particle counter system with 10 and 23 μm cut-off sizes. The ratio of DI mass to total mass injected in one cycle (xDI) was varied at low-, mid-, and high-load operation points at 2000 rpm and stoichiometric conditions. Further investigations for lean-burn concepts with a variation of xDI were carried out and evaluated based on variables such as engine performance, efficiency, and emissions. The measurements show a strong charge cooling effect for DI, thereby reducing NOx, although this effect saturates at a mid-load. By splitting the injected fuel mass, an xDI of 30 % shows the highest reduction in NOx at high-load and a reduction of unburned fuel in the exhaust gas of up to 62 %. Particle measurements indicate the interaction of methanol with the liner for both PFI and DI, leading to increased particle emissions. For high-load and dual injection with xDI = 30 % and 50 %, these emissions are found on a level one magnitude lower than compared to DI operation. Lean burn operation with dual injection shows the extension of the lean burn limit at certain points. However, the potential efficiency increase is diminished by undesirable combustion characteristics with prolonged burn durations.
Fitz, Patrick, Fellner, Felix, Rößlhuemer, Raphael, Härtl, Martin, Jaensch, Malte
Combustion Mode Evaluation of a Methanol–Diesel Dual Direct Injection Engine with a Control of Injection Timing and Energy Substitution Ratio03-18-01-00028/9/2024
Methanol, as a renewable fuel, is an attractive option for internal combustion engines. The dual direct injection method is one of the most promising strategies for applying methanol fuel in diesel engines as the flexible injection control enables combustion mode switching. In this study, a 1-L single-cylinder common-rail diesel engine with a compression ratio of 17.4 is retrofitted by installing an additional methanol direct injector with 35 MPa injection pressure. The engine is operated at 1400 rpm, intermediate load, and fixed midpoint combustion phasing of 10 °CA aTDC with a fixed total amount of energy while applying an energy substitution principle with up to 70% energy supplied by methanol. From the experiments, three distinct combustion modes were identified. When early methanol injection timings were selected in the range of 180–60 °CA bTDC, the primary combustion mode was premixed burn. Late injection timings of 10 °CA bTDC to TDC led to heat release rate shapes of the diffusion flame mode. In between these injection timings, partially premixed combustion was achieved where the higher methanol substitution ratio achieved carbon dioxide (CO2) emissions reduction by up to 11% and nitrogen oxides (NOx) emission suppression by up to 12%. It was also found that with increasing methanol energy substitution ratio, a significant reduction in smoke emissions was achieved. However, the decreased power output and increased emissions of unburnt hydrocarbon (uHC) and carbon monoxide (CO) were measured due to incomplete combustion caused by lower flame temperature of methanol.
Zhao, Yifan, Liu, Xinyu, Kook, Sanghoon
Traceability E-Fuels 20352024-01-30227/2/2024
EU legislation provides for only local CO2 emission-free vehicles to be allowed in individual passenger transport by 2035. In addition, the directive provides for fuels from renewable sources, i.e. defossilised fuels. This development leads to three possible energy sources or forms of energy for use in individual transport. The first possibility is charging with electricity generated from renewable sources, the second possibility is hydrogen generated from renewable sources or blue production path. The third possibility is the use of renewable fuels, also called e-fuels. These fuels are produced from atmospheric CO2 and renewable hydrogen. Possible processes for this are, for example, methanol or Fischer-Tropsch synthesis. The production of these fuels is very energy-intensive and large amounts of renewable electricity are needed. Thus, national production of these fuels in the EU is inefficient in terms of cost and carbon footprint due to the low utilisation rate of renewable energy plants. Outsourcing these processes to regions where renewable energy production takes place under high utilisation rates and thus the amount of installed capacity can be reduced seems to make sense. Nevertheless, it is to be expected that the costs of the renewably produced fuel will be considerably higher than for the respective fossil equivalent. This makes the production and distribution chain susceptible to fraud by mixing it with, or substituting it for, fossil fuel. This problem can only be controlled by appropriate regulations and controls. This paper presents different options for product control and certification, both for the global and the EU trade area. It conceptually discusses different procedures for control, certification and fuel labelling. First, the draft for a global, certificate-based system for production volume control is presented. This draft enables independent trading of certificates and the product. This makes it possible to implement both pure certificate trading and product-linked certificate trading. Thus, each trading zone can implement the system that suits them best, without disturbing the control of the global production volume. In a second step, an automated monitoring system for tracking imported renewable fuels in the EU trading zone is presented. This is done via a second certification authority and continuous digital and governmental monitoring. In a third step, possibilities are presented with which the fuel or the refuelling in the vehicle can be monitored. Finally, a conclusion is given on the practicability of such a monitoring system.
Stoll, Tobias, Kulzer, Andre, Berner, Hans-Juergen
Vehicle Decarbonization: Vol. 1EPRCOMPV2420235/10/2024
Most heavy trucks should be fully electric, using a combination of batteries and catenary electrification, but heavy trucks requiring very long unsupported range will need chemical fuels. Hydrogen is the key to storing renewably generated electricity chemically. At the scale of heavy trucks, compressed hydrogen can match the specific energy of diesel, but its energy density is five times lower, limiting the range to around 2,000 km. Scaling green hydrogen production and addressing leakage must be priorities. Hydrogen-derived electrofuels—or “e-fuels”—have the potential to scale, and while the economic comparison currently has unknowns, clean air considerations have gained new importance. The limited supply of bioenergy should be reserved for critical applications, such as bioenergy with carbon capture and storage (BECCS), aviation, shipping, and road freight in the most remote locations. Additionally, there are some reasons to prefer ethanol or methanol to diesel-type fuels as they are inherently clean burning, more easily synthesized, and more readily produced from cellulosic sources.
Muelaner, Jody E.
Deflagration-Based Knock of Methanol SI Combustion and its Implications for Combustion Noise2024-01-28194/9/2024
Methanol emerges as a compelling renewable fuel for decarbonizing engine applications due to a mature industry with high production capacity, existing distribution infrastructure, low carbon intensity and favorable cost. Methanol’s high flame speed and high autoignition resistance render it particularly well-suited for spark-ignition (SI) engines. Previous research showed a distinct phenomenon, known deflagration-based knock in methanol combustion, whereby knocking combustion was observed albeit without end-gas autoignition. This work studies the implications of deflagration-based knock on noise emissions by investigating the knock intensity and combustion noise at knock-limited operation of methanol in a single-cylinder direct-injection SI engine operated at both stoichiometric and lean (λ = 2.0) conditions. Results are compared against observations from a premium-grade gasoline. Experiments show that methanol’s end-gas autoignition occurs at lean conditions, leading to the typical autoignition-based knock as that occurring with premium-grade gasoline. However, at stoichiometric conditions, knock-limited operation is achieved with deflagration-based knock. Noise of deflagration-based knock has lower variability than that of autoignition-based knock and it does not seem to be an issue at the engine speed tested experimentally in this paper (1400 rpm). However, computational fluid dynamic large eddy simulations show that deflagration-based knock may lead to high noise levels at 2000 rpm. Deflagration-based knock is insensitive to changing spark timings, so new knock mitigation strategies are required, such as adjusting the spark energy and/or adding dilution. Finally, this study shows that deflagration-based-knock may be directly impacted by the flame speed, occurring more frequently with faster-burning fuels or under conditions that elevate flame speeds, like rich-stoichiometric operation. The finding bears implications on renewable e-fuels, such as ethanol, methanol and hydrogen.
Singh, Eshan, Strickland, Tyler, Abboud, Rami, MacDonald, James, Lee, Sanguk, Lopez Pintor, Dario
Methanol Mixing-Controlled Compression Ignition with Ignition Enhancer for Off-Road Engine Operation2024-01-27014/9/2024
Methanol is one of the most promising fuels for the decarbonization of the off-road and transportation sectors. Although methanol is typically seen as an alternative fuel for spark ignition engines, mixing-controlled compression ignition (MCCI) combustion is typically preferred in most off-road and medium-and heavy-duty applications due to its high reliability, durability and high-efficiency. In this paper, the potential of using ignition enhancers to enable methanol MCCI combustion was investigated. Methanol was blended with 2-ethylhexyl nitrate (EHN) and experiments were performed in a single-cylinder production-like diesel research engine, which has a displacement volume of 0.83 L and compression ratio of 16:1. The effect of EHN has been evaluated with three different levels (3%vol, 5%vol, and 7%vol) under low- and part-load conditions. The injection timing has been swept to find the stable injection window for each EHN level and load. With the highest EHN level, better combustion stability and the widest combustion control window were found due to the higher reactivity of the fuel. However, NOx emissions increased as the EHN level increases mainly due to the contribution of the nitrate group of EHN to engine-out NOx. Stable combustion under low-load condition was achieved only with 7%vol EHN. Due to the absence of carbon-to-carbon bonding and high oxygen content in the fuel, highly improved particle emission characteristics were detected regardless the level of EHN. Finally, comparisons against baseline operation with diesel fuel show that higher thermal efficiency values can be reached with methanol MCCI for a given engine-out NOx level due to much lower heat transfer loses.
Lee, Sanguk, Lopez Pintor, Dario, Cho, Seokwon
Experimental Study on Ammonia-Methanol Combustion and Emission Characteristics in a Spark Ignition Engine2024-01-28204/9/2024
Ammonia and methanol are both future fuels with carbon-neutral potential. Ammonia has a high octane number, a slow flame speed, and a narrow ignition limit, while methanol has a fast flame speed with complementary combustion characteristics but is more likely to lead to pre-ignition and knock. In this paper, the combustion and emission characteristics of ammonia-methanol solution in a high compression ratio spark ignition engine are investigated. The experimental results show that the peak in-cylinder pressure and peak heat release rate of the engine when using ammonia-methanol solution are lower and the combustion phase is retarded compared with using methanol at the same spark timing conditions. Using ammonia-methanol solution in the engine resulted in a more ideal combustion phase than that of gasoline, leading to an increase in indicated thermal efficiency of more than 0.6% and a wider range of efficient operating conditions. The use of ammonia-methanol solution increases unburned NH3 emissions and THC emissions, resulting in lower thermal efficiency compared with the use of methanol. Using ammonia-methanol solution reduces CO2 emissions and increases NOx and N2O emissions, eventually resulting in similar greenhouse gases (GHG) emissions to the use of methanol, both of which are 10% lower than the use of gasoline.
Lin, Zhelong, Liu, Shang, Qi, Yunliang, Chen, Qingchu, Wang, Zhi
Investigation of Combustion Characteristics of a Fuel Blend Consisting of Methanol and Ignition Improver, Compared to Diesel Fuel and Pure Methanol2024-01-21224/9/2024
The increasing need to reduce greenhouse gas emissions and shift away from fossil fuels has raised an interest for methanol. Methanol can be produced from renewable sources and can drastically lower soot emissions from compression ignition engines (CI). As a result, research and development efforts have intensified focusing on the use of methanol as a replacement for diesel in CI engines. The issue with methanol lies in the fact that methanol is challenging to ignite through compression alone, particularly at low-load and cold starts conditions. This challenge arises from methanol's high octane number, low heating value, and high heat of vaporization, all of which collectively demand a substantial amount of heat for methanol to ignite through compression. One successful project using methanol is the Fastwater project, where a diesel engine was converted to run on methanol, with 3% ignition improver, and installed in the pilot boat Pilot 120SE, that is running in real world conditions off the east coast of Sweden. The aim of this paper is to evaluate the performance of a fuel blend comprising of 97% methanol and 3% ignition improver (MeOH97), as is utilized in the pilot boat, on a heavy duty CI engine test bench. This evaluation involved a comparison with both diesel fuel and non-blended methanol (MeOH100). The results indicated that, in terms of gross indicated efficiency, MeOH97 is on par with diesel for most load conditions and can potentially even surpass it at higher loads. It is only at the lowest tested load that MeOH97 exhibits a drop in efficiency, although combustion remains stable. Furthermore, the results confirm that the addition of a 3% ignition improver significantly improves the combustibility of methanol, particularly at lower loads. Lastly, the use of methanol leads to a noteworthy reduction in NOx emissions without generating any soot emissions.
Svensson, Magnus, Tuner, Martin, Verhelst, Sebastian
Experimental Investigation of Pilot Injection Strategies to Aid Low Load Compression Ignition of Neat Methanol2024-01-21194/9/2024
The growing demand to lower greenhouse gas emissions and transition from fossil fuels, has put methanol in the spotlight. Methanol can be produced from renewable sources and has the property of burning almost soot-free in compression ignition (CI) engines. Consequently, there has been a notable increase in research and development activities directed towards exploring methanol as a viable substitute for diesel fuel in CI engines. The challenge with methanol lies in the fact that it is difficult to ignite through compression alone, particularly in low-load and cold start conditions. This difficulty arises from methanol's high octane number, relatively low heating value, and high heat of vaporization, collectively demanding a considerable amount of heat for methanol to ignite through compression. Previous studies have addressed the use of a pilot injection in conjunction with a larger main injection to lower the required intake air temperature for methanol to combust at low loads. While this approach has shown promise, there has been limited testing and documentation of how the pilot injection should be configured for optimal results. The research presented in this study explored combinations of six different dwell times, between the pilot and the main injections, with three different pilot injection lengths. The findings demonstrated that a dwell time ranging from 15 to 20 CAD, combined with a pilot injection of 250 to 375 μs, can lead to highly stable combustion at an intake air temperature more than 30°C lower than that required when not using a pilot injection. Additionally, these configurations resulted in a five percentage point increase in efficiency, comparable CO and HC emissions, and significantly reduced NOx emissions. In summary, the study highlighted the effectiveness of using a specific pilot injection in enhancing combustion stability, efficiency, and emissions during low-load methanol compression ignition operation.
Svensson, Magnus, Tuner, Martin, Verhelst, Sebastian
Modeling and Analysis of the Hydrogen Production via Steam Reforming of Ethanol, Methanol, and Methane Fuels2024-01-21794/9/2024
The global transition to alternative power sources, particularly fuel cells, hinges on the cost-effective production and distribution of hydrogen fuel. While green hydrogen produced through water electrolysis using renewable energy sources holds immense promise, it currently falls short of meeting the burgeoning demand for hydrogen. To address this challenge, alternative methods, such as steam reforming and partial oxidation of hydrocarbon fuels with integrated carbon capture, are poised to bridge the gap between supply and demand in the near to midterm. Steam reforming of methane is a well-established technology with a proven track record in the chemical industry, serving as a dependable source of hydrogen feedstock for decades. However, to meet the demand for efficient hydrogen storage, handling, and onboard reforming, researchers are increasingly exploring liquid hydrocarbon fuels at room temperature, such as methanol and ethanol. In this work, we have developed reformer models for ethanol, methanol, and methane within the GT-SUITE software, drawing on data from the existing body of research. We examine fuel conversion and hydrogen yield under varying conditions, including different feed temperatures, flow rates, and catalyst loadings. These reactor models hold the potential for seamless integration into system-level models, designed to investigate onboard fuel reforming, startup and shutdown procedures, carbon capture, and more.
Hariharan, Deivanayagam, Chhatija, Harish, Brown, Jonathan, Gundlapally, Santhosh
A Comparative Study of Knock Formation in Gasoline and Methanol Combustion Using a Multiple Spark Ignition Approach: An Optical Investigation2024-01-21054/9/2024
Engine knock is a major challenge that limits the achievement of higher engine efficiency by increasing the compression ratio of the engine. To address this issue, using a higher octane number fuel can be a potential solution to reduce or eliminate the propensity for knock and so obtain better engine performance. Methanol, a promising alternative fuel, can be produced from conventional and non-conventional energy resources, which can help reduce pollutant emissions. Methanol has a higher octane number than typically gasolines, which makes it a viable option for reducing knock intensity. This study compared the combustion characteristics of gasoline and methanol fuels in an optical spark-ignition engine using multiple spark plugs. The experiment was carried out on a single-cylinder four-stroke optical engine. The researchers used a customized metal liner with four circumferential spark plugs to generate multiple flame kernels inside the combustion chamber. The results indicated that generating multiple flames inside the cylinder caused higher pressures and temperatures, which led to the production of more knocking cycles with higher knock intensities. Additionally, the study showed that methanol combustion produced significantly lower knock intensity with better engine power output compared to gasoline combustion due to its higher octane rating enabling more advanced ignition and its faster flame propagation. The researchers characterized various knock intensities obtained by multiple ignition sites and exhibited a transition from normal combustion to slight knock, medium knock, and high knock cases. Furthermore, the researchers performed high-speed natural-flame-luminosity (NFL) imaging to capture the multiple flame development and autoignition kernels inside the cylinder for various combustion cases. This study provides a detailed understanding of the combustion characteristics of gasoline and methanol fuels in a spark-ignition engine and can be used to further optimize engine performance by reducing knock intensity and increasing engine efficiency.
Uddeen, Kalim, Tang, Qinglong, Shi, Hao, Almatrafi, Fahad, Magnotti, Gaetano, Turner, James
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