Experimental evaluation of nanobiochar and metallic oxide nanoparticles with Croton macrostachyus seed oil biodiesel on combustion and emission characteristics

Despite its higher density, viscosity, and lower calorific value, biodiesel has been explored as an alternative energy source to diesel fuel. This study investigated biodiesel produced from croton macrostachyus (CMS) seed, a non-edible feedstock. The research aimed to experimentally analyze cylinder pressure, heat release rate, and ignition delay, as well as engine performance and emission characteristics, at a constant speed of 2700 rpm under varying loads (0–80%) using diesel, B10, B15, B20, and B25 blended fuels. Among the tested blends, B25 exhibited superior performance, achieving the highest peak cylinder pressure (CP) of 58.21 bar and a maximum heat release rate (HRR) of 543.9 J/CA at 80% engine load. Conversely, B20 at 60% engine load, followed by B25 and pure diesel at 80% engine load, demonstrated the shortest ignition delay (ID) and the most advanced start of combustion (SoC). Compared to the biodiesel blends, pure diesel showed: a 5.5–14% increase in brake thermal efficiency (BTE), a 17–26% decrease in brake-specific fuel consumption (BSFC), and a 7–12% reduction in exhaust gas temperature (EGT). Regarding emissions, carbon monoxide (CO) and hydrocarbon (HC) emissions were lower for pure diesel, while carbon dioxide (CO2) and nitrogen oxide (NOx) emissions were higher for biodiesel blends, attributed to their inherent oxygen content. In conclusion, CMS biodiesel displays promising characteristics, suggesting its potential suitability for use in internal combustion engines.

As the environment is humiliated at a disturbing rate, most governments have persistent calls following global energy policies for the utilization of biofuels. This paper essentially examines the portrayal investigations of fatty acid methyl esters and fatty acid pentyl esters obtained from palm oil. The characterization studies such as gas chromatogram, mass spectrometry, and Fourier transformed infrared spectrometry have been performed to study biodiesel’s chemical composition. This article likewise shows biodiesel’s physiochemical properties and concentrates on biodiesel blends’ hypothetical combustion properties with Al2O3 nanoparticles. The spectroscopic investigations demonstrate the contiguity of eight methyl esters and five pentyl esters prevalently of palmitic acid, oleic acid, octanoic acid, and stearic acid. The esters’ nearness was additionally affirmed by the FTIR range, where the peaks in the scope of 1700 cm−1 to 1600 cm−1 can be observed. Looking at the thermophysical properties of the mixes with that of the base diesel fuel yielded the compromising results by giving the comparative density to that of the diesel fuel. The palm oil biodiesel’s calorific value is, by all accounts, diminished by 10% when contrasted with diesel fuel. The addition of the nanoparticles up to 1 g has raised the calorific value most closely to the diesel’s value. Correspondingly, the theoretical burning examinations have demonstrated the limit of biodiesel to go about as an option compared to consistent diesel in the conventional DI–CI engine. This article talks about the combustion attributes of the blend containing 60% diesel, 20% fatty acid methyl ester (FAME), and 20% fatty acid pentyl ester (FAPE) with aluminium oxide (Al2O3) nanoparticles at two distinctive concentrations. This article primarily concerns the inquiry of combustion criterion, such as in-chamber pressure variation, rate of heat release, start of combustion, end of combustion, and ignition delay for considered fuel blends when contrasted with neat diesel fuel in a four-stroke, direct-injection, single-cylinder diesel engine. The results showed a decrease in in-cylinder pressure at all loads of engine operation for biodiesel blends when compared with neat diesel, irrespective of the nanoparticle concentration. Biodiesel blends at all nanoparticle concentrations showed an increase in ignition delay compared with diesel fuels at all engine operation loads. The performance results show a slight deterioration in the engine’s thermal efficiency using biodiesel blends, irrespective of the nanoparticle concentration. Additionally, the emissions show a considerable fall in trends for all loads in contrast with diesel fuel.

The combustion duration in an internal combustion engine is the period bounded by the engine crank angles known as the start of combustion (SOC) and end of combustion (EOC), respectively. This period is essential in analysis of combustion for the such as the production of exhaust emissions. For compression-ignition engines, such as diesel engines, several approaches were developed in order to approximate the crank angle for the start of combustion. These approaches utilized the curves of measured in-cylinder pressures and determining by inspection the crank angle where the slope is steep following a minimum value, indicating that combustion has begun. These pressure data may also be utilized together with the corresponding cylinder volumes to generate the apparent heat release rate (AHRR), which shows the trend of heat transfer of the gases enclosed in the engine cylinder. The start of combustion is then determined at the point where the value of the AHRR is minimum and followed by a rapid increase in value, whereas the EOC is at the crank angle where the AHRR attains a flat slope prior to the exhaust stroke of the engine. To verify the location of the SOC, injection line pressures and fuel injection timing are also used. This method was applied in an engine test bench using a four-cylinder common-rail direct injection diesel engine with a pressure transducer installed in the first cylinder. Injector line pressures and fuel injector voltage signals per engine cycle were also recorded and plotted. By analyzing the trends of this curves in line with the generated AHRR curves, the SOC may be readily determined.

Performance enhancement and emission reduction of CRDI diesel engine fueled using Manilkara Zapota biodiesel blend with TiO2 nanoadditive

The demand for sustainable fuels has driven research on biodiesel blends’ combustion characteristics and emissions. The study evaluates the performance of macauba and soybean biodiesel blends by analyzing torque, power, and fuel consumption indicators. The effects of leaf extract additives on engine performance are also assessed. Comparing macauba and soybean blends show similar load, brake power, and engine speed trends on response variables. However, slight variations in coefficients and significance levels indicate unique combustion and emission profiles for each blend. Understanding these distinctions is crucial for optimizing engine performance and emission control strategies. Parameters analyzed include brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), exhaust gas temperature (EGT), carbon monoxide (CO) emissions, hydrocarbon (HC) emissions, oxides of nitrogen (NOx) emissions, smoke opacity, cylinder pressure, heat release rate, and ignition delay. Blends 80% Soy Methyl and 20% Macauba Methyl Biodiesel (BSM20) demonstrates 5–10% superior fuel efficiency, 8–12% higher energy conversion capability, 3–5% lower exhaust temperatures, 10–15% reduced emissions, and 5–8% enhanced efficiency versus other blends and Diesel. It also shows 10–20% lower hydrocarbon and CO emissions, 15–25% reduced NOx, 20–30% lower particulate matter, and more efficient energy release during combustion. Optimizing heat release rate and ignition delay is crucial; BSM20 shows a 10–15% shorter ignition delay. Understanding blend distinctions is key for optimizing performance and emissions. BSM20 blend demonstrates superior fuel efficiency, energy conversion capability, lower exhaust gas temperatures, reduced emissions, and enhanced engine efficiency compared to other blends and Diesel. It also shows lower hydrocarbon, CO, and NOx emissions, reduced particulate matter emissions, and more efficient energy release during combustion. Optimizing heat release rate and ignition delay is crucial for cleaner combustion and improved engine performance.

Effect on the performance and emissions of methanol/diesel dual-fuel engine with different methanol injection positions

Bu çalışmada EURO 5 emisyon standartlarını sağlayan 1,5 litrelik dizel motora sahip Ford Fiesta üzerinde biyodizelin emisyonlara, performansa ve yanma karakteristiğine olan etkilerini incelemek için şasi dinaomometresinde deneyler yapılmıştır. Çalışma kapsamında kanola yağından elde edilen biyodizel ile harmanlanmış 4 farklı yakıt ve saf biyodizel kullanılmıştır. Deneyler esnasında egzoz emisyonları, araç üstü hata denetleme portu üzerinden motor sensor verileri, motorun ikinci silindirinden silindir içi basınç ve enjektör akım sinyali bilgileri sürekli olarak ölçülmüştür. Biyodizelin yanma karakteristiği üzerindeki etkisini inceleyebilmek için indikatör diagramı kullanılarak ısı yayılım oranı, silindir içi ortalama sıcaklık, yanma başlangıç zamanı, tutuşma gecikmesi ve yanma süresi hesaplanmıştır. Elde edilen sonuçlara göre biyodizel katkılı yakıt saf dizele göre daha düşük sıcaklık ve basınç altında tutuşmaya başladığı gözlemlenmiştir. Dizele biyodizel eklenmesi yanma tutuşma gecikmesini azaltmış ve püskürtülen yakıtın daha erken yanmasına sebep olmuştur. Ek olarak biyodizel katkısı HC, CO ve kurum emisyonlarını iyileştirmiştir, ancak düşük ısıl değeri nedeniyle yakıt tüketiminin artmasına neden olmuştur. Ayrıca artan biyodizel miktarı ile NOx emisyonlarında artış gözlemlenmiştir.

Over the last few decades, emissions regulations for internal combustion engines have become increasingly restrictive, pushing researchers around the world to exploit innovative propulsion solutions. Among them, the dual fuel low temperature combustion (LTC) strategy has proven capable of reducing fuel consumption and while meeting emissions regulations for oxides of nitrogen (NOx) and particulate matter (PM) without problematic aftertreatment systems. However, further investigations are still needed to reduce engine-out hydrocarbon (HC) and carbon monoxide (CO) emissions as well as to extend the operational range and to further improve the performance and efficiency of dual-fuel engines. In this scenario, the present study focuses on numerical simulation of fumigated methane-diesel dual fuel LTC in a single-cylinder research engine (SCRE) operating at low load and high methane percent energy substitution (PES). Results are validated against experimental cylinder pressure and apparent heat release rate (AHRR) data. A 3D full-cylinder RANS simulation is used to thoroughly understand the influence of the start of injection (SOI) of diesel fuel on the overall combustion behavior, clarifying the causes of AHRR transition from two-stage AHRR at late SOIs to single-stage AHRR at early SOIs, low temperature heat release (LTHR) behavior, as well as high HC production. The numerical campaign shows that it is crucial to reliably represent the interaction between the diesel spray and the in-cylinder charge to match both local and overall methane energy fraction, which in turn, ensures a proper representation of the whole combustion. To that aim, even a slight deviation (∼3%) of the trapped mass or of the thermodynamic conditions would compromise the numerical accuracy, highlighting the importance of properly capturing all the phenomena occurring during the engine cycle. The comparison between numerical and experimental AHRR curves shows the capability of the numerical framework proposed to correctly represent the dual-fuel combustion process, including low temperature heat release (LTHR) and the transition from two-stage to single stage AHRR with advancing SOI. The numerical simulations allow for quantitative evaluation of the residence time of vapor-phase diesel fuel inside the combustion chamber and at the same time tracking the evolution of local diesel mass fraction during ignition delay — showing their influence on the LTHR phenomena. Oxidation regions of diesel and ignition points of methane are also displayed for each case, clarifying the reasons for the observed differences in combustion evolution at different SOIs.

<title>ABSTRACT</title> <p>Cylinder Pressure Monitoring (CYPRESS<sup>™</sup>). This technology provides closed-loop feedback to enable a real-time calculation of the apparent heat release rate (AHRR). This makes it possible to adapt to the fuel ignition quality (cetane number) by adjusting the pilot injection quantity and the placement of the pilot and main injection events. This enables the engine control system to detect fuel quality and adapt the ignition sequence accordingly.</p> <p>This technology is also used to infer the total fuel energy injected by analyzing the AHRR, making it possible to vary the injected fuel volume quantity to achieve consistent (+/- 2%) full load power as the fuel energy density varies. Analysis of the position of AHRR with respect to the crank angle (CA) is dependent on the start of injection and subsequent fuel shots. The ability to control the position of the AHRR maintains thermal efficiency as fuel properties vary which are implemented by controlling the fuel injection pulse widths and common rail injection pressure levels.</p> <p>Key to the development of the control system and subsequent adaptation to a corresponding engine is the AVL analysis and simulation tool suite as follows: <list list-type="bullet"> <list-item> <p>BOOST—One-dimensional thermodynamic modeling of the engine system</p></list-item> <list-item> <p>FIRE—Detailed fluid mechanics of compressible and incompressible fluid flows in the engine</p></list-item> <list-item> <p>Engine Simulation Environment (ESE) Diesel— Simulation of the fluid mechanics and chemistry of the diesel combustion process.</p></list-item></list></p> <p>Through the use of a cylinder pressure sensor, the engine controller will be able to map the development of the AHRR and the mass fuel burn point (MFB50%), which provides good thermal efficiency correlation. The cylinder pressure map detects the start of combustion (SOC) and the feedback controller adjusts the start of injection (SOI) to maintain the SOC in the ideal crank position.</p> <p>The cylinder pressure sensor allows for accurate measurement of the power produced. By varying the volume of fuel in each injection shot the controller actively manages the engine power and noise signature with different fuels (e.g. DF-2, JP-8, JP-5, etc).</p> <p>The initial concept for this approach was derived from AVL’s suite of hardware and software tools developed for base engine combustion research and development. This technology is now licensed to major OEMs and is in production vehicles in Europe.</p>

<div class="section abstract"><div class="htmlview paragraph">An investigation of the performance and emissions of a Fischer-Tropsch Coal-to-Liquid (CTL) Iso-Paraffinic Kerosene (IPK) was conducted using a CRDI compression ignition research engine with ULSD as a reference. Due to the low Derived Cetane Number (DCN), of IPK, an extended Ignition Delay (ID), and Combustion Delay (CD) were found for it, through experimentation in a Constant Volume Combustion Chamber (CVCC). Neat IPK was analyzed in a research engine at 4 bar Indicated Mean Effective Pressure (IMEP) at three injection timings: 15°, 20°, and 25° BTDC. Combustion phasing (CA50) was matched with ULSD at 10.8° and 16° BTDC. The IPK DCN was found to be 26, while the ULSD DCN was significantly higher at 47 in a PAC CID 510. In the engine, IPK’s DCN combined with its short physical ignition delay and long chemical ignition delay compared to ULSD, caused extended duration in Low Temperature Heat Release (LTHR) and cool flame formation. It was found in an analysis of the Apparent Heat Release Rate (AHRR) curve for IPK that there were multiple Negative Temperature Coefficient (NTCR) regions before the main combustion event. The High Temperature Heat Release (HTHR) of IPK achieved a greater peak heat release rate compared to ULSD. Pressure rise rate for IPK was observed to increase significantly with increase in injection timing. The peak in-cylinder pressure was also greater for IPK when matching CA50 by varying injection timing. Emissions analysis revealed that IPK produced less NO<sub>x</sub>, soot, and CO<sub>2</sub> compared to ULSD. CO and UHC emissions for IPK increased.</div></div>

Combustion behaviour of a heavy duty common rail marine Diesel engine fumigated with propane

Ignition delay, combustion and emission characteristics of diesel engine fueled with biodiesel

Computational simulations of engine combustion processes are increasingly relied upon to lead the design of advanced IC engines. Both computational fluid dynamics (CFD) simulations as well as thermodynamics-based phenomenological 0D or 1D gas dynamics simulations are examples of current simulation strategies. Before simulations can be utilized to guide the design process, they must be validated with experimental results. Typically, the experimental data used for validation of computational simulations include in-cylinder pressure and apparent heat release rate (AHRR) histories. However, the process of comparison of experimental and simulated pressure and AHRR curves is largely qualitative; therefore, the validation process is mostly visual. In the present work, the authors introduce a framework for quantifying uncertainties in experimental pressure data, as well as uncertainties in the “average” AHRR curve that is derived from ensemble-averaged cylinder pressure histories. Predicted AHRR curves from CFD simulations are also quantitatively compared with the experimental AHRR bounded by “uncertainty bands” in the present work.

The use of biodiesel as an alternative to conventional diesel fuels has gained significant attention due to its potential for reducing greenhouse gas emissions and improving energy sustainability. This study explores the impact of TiO2 nanoparticles on the emission characteristics and combustion efficiency of biodiesel blends in compression ignition (CI) engines. The fuels analyzed include diesel, SB20 (soybean biodiesel), SB20 + 50 TiO2 ppm, SB20 + 75 TiO2 ppm, PB20 (palm biodiesel), PB20 + 50 TiO2 ppm, and PB20 + 75 TiO2 ppm. Experiments were conducted under a consistent load of 50% across engine speeds ranging from 1000 to 1800 RPM. While TiO2 nanoparticles have been widely recognized for their ability to enhance biodiesel properties, limited research exists on their specific effects on soybean and palm biofuels. This study addresses these gaps by providing a comprehensive analysis of emissions, including NOX, CO, CO2, and HC, as well as exhaust gas temperature (EGT), across various engine speeds and nanoparticle concentrations. The results demonstrate that TiO2 nanoparticles lead to a reduction in CO emissions by up to 30% and a reduction in HC emissions by 21.5% at higher concentrations and engine speeds. However, this improvement in combustion efficiency is accompanied by a 15% increase in CO2 emissions, indicating more complete fuel oxidation. Additionally, NOX emissions, which typically increase with engine speed, were mitigated by 20% with the addition of TiO2 nanoparticles. Exhaust gas temperatures (EGTs) were also lowered, indicating enhanced combustion stability. These findings highlight the potential of TiO2 nanoparticles to optimize biodiesel blends for improved environmental performance in CI engines.

The present work investigates the influence of fuel injection pressure on the combustion and emission characteristics of ultra-low diesel fuel for high speed direct injection ( HSDI) diesel engine at different fuel injection timings( -12,-9,-6,-3,0 ) ATDC has been made . The fuel injection pressure were(800,1000,1200) bar and at high load ( 80Nm= 5BMAP) , low load ( 40Nm=2.5BMAP ) , With constant engine speed ( 1500rpm) . In-cylinder pressure was measured and analyzed using LABVIWE program .A calculation program specially written in MATLAB software was used to extract the apparent heat release rate, the ignition delay, combustion duration and specifies the amount of heat released during the premixed and diffusion combustion phases ( premixed burn fraction PMBF) and ( diffusion burn fraction DBF). The influence of injection pressure on the exhaust emissions such as carbon monoxide (CO), total hydrocarbons (THCs), nitric oxides (NOx), smoke number (SN) and fuel consumption were also investigated.A result referring to that when the injection pressure was increased, the ignition delay reduced. A shorter ignition delay at high injection pressure also advanced the combustion, and increased the in-cylinder pressure, heat release rate and their peaks respectively .The premixed burn fraction increased with fuel injection pressure increasing, and this caused a decrease in each of the exhaust SN, THC and CO emissions but the NOx emissions increased.