Unburned Hydrocarbons Research Articles

Experimental Investigations on exhaust emissions with an air gap insulated engine

Experiments were carried out to study exhaust emissions of diesel engine withair gap insulated low heat rejection (LHR–2) combustion chamber consisting of air gap insulated piston with 3mm air gap, with Superni (an alloy of nickel) crown and air gap insulated liner with superni insert with neat diesel with varied injection timing. Exhaust emissions of particulate emissions, nitrogen oxide (NOx) levels, carbon monoxide (CO) and un-burnt hydrocarbons (UBHC) were determined at various values of brake mean effective pressure (BMEP) of the LHR-2 combustion chamberand compared with neat diesel operation on conventional engine (CE) at similar operating conditions. The optimum injection timing was found to be 31obTDC (before top dead centre) with conventional engine, while it was 29obTDC for engine with LHR–2 combustion chamber with diesel operation. Engine with LHR–2 combustion chamber with neat diesel operation showed increased pollution levels at manufacturer’s recommended injection timing of 27obTDC, and they improved marginally with advanced injection timing of 29obTDC in comparison with CE at 27obTDC. The exhaust emissions from diesel engine cause health hazards and also environmental disorders. Hence, controlling of these emissions in an important and urgent step.

Performance and emission characteristics of Mahua blended biodiesel

In India, Mahua trees are tropical tree, generally found in the northern and central forests. Due to large amount of carbon emission from natural diesel into the environment, it causes to pollution and climate change that could affect health of livelihood. Therefore, it has to shift to some alternate fuel in place of natural diesel that can reduce carbon and pollution emission to the environment. That’s why we opted to blend natural diesel with Mahua oils. Since Mahua trees are cultivated in humid and warm region and it is producing 30 to 200 kg of seeds yearly per tree depending on its maturity. Therefore, it is cheap and easy availability of Mahua seeds can provide a raw material for blending of diesel fuels. The reduction of thermal efficiency by Mahua mixed biodiesel has major challenge. The natural diesel blended with the proportion of starting increasing from (5 to 20 %) of Mahua seeds oil and starting reduction from (95 to 80 %) of natural diesel oil. The diesel engine were operated on the basis of different Mahua seeds oil quantity with natural diesel, and it observed the highest thermal efficiency of blended biodiesel were at (20 %:80 %) of Mahua seeds oil and natural diesel oil respectively. The aim of this experimental is to utilize of Mahua seeds and to check performance and emission characteristics of Mahua blended biodiesel. Further emissions like CO, NOx, un-burnt hydrocarbon, smokes etc. are analyzed with using diesel engine cylinder.

Experimental analysis of nano additive blended in Mahua oil biodiesel on engine characteristics

Fossil fuel depletion and environmental degradation are currently facing the planet. Increased automobile, power plants, and factories emit more carbon monoxide (CO), unburnt hydrocarbon (HC), and nitric oxide (NOx) emissions as a result of increased automobiles, power plants, and factories. As a result, the globe is looking for an alternative fuel that will not hurt the environment and will also be less expensive. It should also be renewable resources. It pushes the car into the next generation. Vegetables, which satisfy the need for physical and chemical qualities of mineral diesel in the current context. When vegetable oil is used in a diesel engine, it has a negative impact on performance and durability. As a result, the oil should be converted to biodiesel. Transesterification is a useful procedure for changing the properties of raw oil. One of the most essential solutions to the global energy dilemma is biodiesel. The performance and emission parameters of Mahua oil bio-diesel were investigated in this study (MOB). Additives are used to improve biodiesel's combustion properties. Tests were conducted across the whole spectrum of engine operation and under various load circumstances. Engine performance factors like as specific consumption, braking thermal efficiency, and exhaust gas emissions are reduced as biodiesel concentration is increased. MOB blends can be used to replace diesel in diesel engines used in transportation and agriculture.

Possibilities of Ammonia as Both Fuel and NOx Reductant in Marine Engines: A Numerical Study

Nowadays, the environmental impact of shipping constitutes an important challenge. In order to achieve climate neutrality as soon as possible, an important priority consists of progressing on the decarbonization of marine fuels. Free-carbon fuels, used as single fuel or in a dual-fuel mode, are gaining special interest for marine engines. A dual fuel ammonia-diesel operation is proposed in which ammonia is introduced with the intake air. According to this, the present work analyzes the possibilities of ammonia in marine diesel engines. Several ammonia-diesel proportions were analyzed, and it was found that when the proportion of ammonia is increased, important reductions of carbon dioxide, carbon monoxide, and unburnt hydrocarbons are obtained, but at the expense of increments of oxides of nitrogen (NOx), which are only low when too small or too large proportions of ammonia are employed. In order to reduce NOx too, a second ammonia injection along the expansion stroke is proposed. This measure leads to important NOx reductions.

EXPERIMENTAL INVESTIGATION OF DIESEL-ETHANOL FUEL BLENDS IN A COMPRESSION IGNITION ENGINE

Depletion of fossil fuels and environmental pollution has led researchers to foresee the need to develop biofuels. Alcohols are a major component of biofuels. The interest in biofuels was stimulated by fossil fuel depletion and global warming. Ethanol is a promising alternative applicable in internal combustion engines by virtue of its sustainability and soot-reducing potential. This paper deals with the analysis of the impact of different fuel blends of diesel-ethanol on the performance and emissions in a compression ignition (CI) engine. Three different proportions of 100% diesel (E0), 90% diesel-10% ethanol (E10), and 80% diesel-20% ethanol (E20) by volume are blended with diesel that is being used as fuel. Tests were conducted on a liquid-cooled three-cylinder direct injection (DI) diesel engine at 0%, 25%, 50%, 75%, and 100% load conditions at various ethanol mass. The effects of blended fuels on engine performance were investigated, and results showed that E10 presents the highest volumetric efficiency; on the other hand, E20 showed the lowest volumetric efficiency. Maximum in-cylinder pressure occurred with conventional diesel combustion. Results indicated that the concentrations of CO2 and HC (unburnt hydrocarbons) emissions were not significantly different. E10 presented the lowest CO emissions at all engine loads. Additionally, NO emissions peaked with E20 at 75% load.

Study on emission reduction techniques by in-cylinder reduction method for compression ignition engines

Internal Combustion Engines have been one of the contributors of urban air pollution. The usage of CI engines in the locomotives and other applications are inevitable. Emissions from the diesel engines are a major concern. In this paper, an ephemeral examination of the significant studies involving the engine’s characteristics especially those involved in emissions and performance powered with biodiesel blends, biodiesel blends doped with additives, in-cylinder reduction technique in CI engine are presented. The usage of biodiesel in the CI engine results in improved performance with a slender decrease in the engine power and also decrease in emissions of carbon monoxide, nitrogen oxide and unburnt hydrocarbon. However, emission reduction technologies improve the emission results and doping of fuel with additives results in stabilization of engine power. It is understood from the study that emission could be reduced when the engine is run at conditions like 20% blended fuel, lower weight percentage of biologically derived fuel additive, 20% EGR with 20% blended fuel. In most of the cases, a decrease in engine performance up to 5% are recorded due to increase in specific fuel consumption leading to decrease in thermal efficiency.

Sustainability Improvement of Ethanol Blended Gasoline Fuelled Spark Ignition Engine by Nanoparticles

The sophisticated technology being used in automotive technology, as well as the increased use of vehicles, enables the engine to operate on a variety of alternative fuels. Natural or synthetic carbon‐based connections are responsible for the formation of ethanol. They may be produced from a variety of sources, including agricultural feedstock, local crops, and even agricultural trash and waste products. Because they are in the form of a renewable resource, they may be employed in a variety of applications, including IC engines, where they can be used as fuel or as an addition, depending on their composition. It is possible to dramatically improve the performance of gasoline engines using a novel mix of nanoadditives, ethanol, and gasoline while simultaneously reducing the negative environmental impact. An ethanol‐gasoline combination was used to power the engine in this work, which examined the effects of the alumina nanoaddition. Results reveal that thermal efficiency can be improved by up to 17% while fuel consumption can be reduced by up to 16% on a volume basis, indicating a considerable improvement over the basic engine. Also validated was a decrease in dangerous carbon monoxide emissions of as much as 14%, a reduction in unburned hydrocarbon emissions of 18.5%, and a significant reduction in oxygen of as much as 18%.

Sustainability and Environmental Impact of Ethanol and Oxyhydrogen Addition on Nanocoated Gasoline Engine.

Climate change, clean air, renewable energy, nontoxic surroundings, and the opportunity to live in a healthy community are just few of the issues that environmental sustainability addresses. To improve environmental health and quality of life, several researchers have turned their attention to alternative energy sources like ethanol and oxyhydrogen. In latest years, significant progress has been made in the development of ethanol and hydrogen as clean energy sources. A higher octane rating is achieved by mixing ethanol with gasoline rather than using regular gasoline. A novel mix of oxyhydrogen, ethanol, and gasoline is ecologically friendly while simultaneously increasing the performance of gasoline engines. In this study, a nanoparticle-coated piston on a low heat rejection gasoline engine fuelled by an ethanol-gasoline mix with oxyhydrogen addition was investigated. It has been evaluated that thermal efficiency improved by up to 25% while fuel consumption can be reduced by up to 28% on a volume basis compared to the baseline engine. Furthermore, the decrease in harmful carbon monoxide reached around 10%, and the reduction in unburned hydrocarbon emissions reached 18%.

Interpretation of the performance and emission characteristics of a CI engine running on ethanol-butanol diesel blends using an optimisation model

Every nation is attempting to minimise pollution in a variety of ways as government's upcoming laws and bills on emissions mitigation have sped up engine development. Our research's goal is to investigate alternative optimisation models for emission and performance to find the optimal ethanol-butanol diesel blends. This research looked at CO, CO2, NOx, and HC levels as emission parameters. Minor variations in the performance metrics like brake thermal efficiency (BTE), brake power, torque, and mechanical efficiency were recorded. It was evident from the graphs that the performance characteristics were slightly higher than neat diesel and except for the amount of unburned hydrocarbon, there has been a substantial improvement in emission characteristics. The goal of optimisation is to find the best alcohol diesel mix percentage that can be utilised in a diesel engine. The ideal mix is chosen based on the desirability value derived from the optimisation data.

Effects of high-temperature CeO2 calcination on the activity of Pt/CeO2 catalysts for oxidation of unburned hydrocarbon fuels

High temperature (800 °C) pre-calcination of CeO2 support decreases the surface defects and improves the mobility of surface lattice oxygen. As a result, the supported Pt clusters have higher oxygen coverage and superior HC oxidation activity.

Robust Temperature Control for an Electrically Heated Catalyst using First Order Sliding Mode and Supertwisting Controllers

The main contribution of this paper is to appraise the performance of first order sliding mode (FOSMC) and Supertwisting (STC) controllers when tracking an electrically heated three way catalysts (EHTWC) solid temperature. The model of the EHTWC is developed based on similar ones approved by literature, yet it is highly simplified to be well-suited for implementation in a Hardware in the Loop framework. The reference temperature is designed to fasten the light-off temperature making the catalyst effective when lowering carbon monoxide and total unburned hydrocarbons. Numerical analysis provided in this work shows that both proposed controllers ensure full oxidation of targeted pollutants after only 75 seconds during a cold start scenario subject to exhaust flow rate disturbance.

Benzin-metanol (M5-M10) karışımlarının SI motorundaki performans üzerine deneysel bir araştırması

Methanol is one of the promising alternative fuels for spark-ignition engines. It has a high octane number, increasing the octane number of gasoline that influence engine setting parameters. Ignition timing and injection duration are two engine setting parameters that influence the combustion process and emission of spark-ignition engine, which are therefore fascinating to be studied. The main objective of this work was to improve the performance of gasoline-methanol blends in a spark-ignition engine, which was carried out by optimization of engine operational parameters, which were ignition timing and injection duration. Performance parameters measured in this study were engine torque, power, and specific fuel consumption. An emission parameter such as carbon dioxide, carbon monoxide, and unburnt hydrocarbons was measured to evaluate the combustion process. Test results were analyzed by comparing performance and emission parameters of the engine on its standard and optimized settings. The result obtained that optimized ignition timing and injection duration sets products in an increase in engine torque and power, which are up to 12.99% and 1.72%, respectively, and 7.29% decrease in specific fuel consumption than engine with standard-setting using the same fuel blend. In addition, there was a decrease of carbon monoxide in exhaust emission, and unburnt hydrocarbon was slightly increased.

Evaluation of TiO2 Nanoparticles as an Additive in Diesel-n-Butanol - Bombax Ceiba Biodiesel Blends for Enhance Performance and Emissions Control of a CI Engine

In this study, additions of Titanium dioxide nanoparticles into diesel- Bombax ceiba methyl ester (BCME) and n-butanol (C4H9OH) and the impact of nano particles on the emission and performance characteristics of a diesel engine were studied experimentally. The n-butanol in fuel samples significantly influenced the physicochemical properties of the blends. The TiO2 nanoparticles were added at different concentrations of 30, 60, and 90 ppm. The ratio of 1:4 TiO2: QPAN 80 was observed to deliver maximum possible stability in biodiesel. In addition, more oxygen in n-butanol and nano additives minimize environmental air pollution. The experiments employed Diesel, B20, B20Bu10, B20Bu10T30, B20Bu10T60, and B20Bu10T90 blends using the four-stroke, direct injection diesel engine with single-cylinder. The experimental results showed that adding 60 ppm TiO2 nano particles in B20Bu10 improved thermal efficiency by 8.36% and reduced the brake-specific fuel consumption by 21.6% compared to B20Bu10. The B20Bu10T60 blend reduced the carbon monoxide (CO) and unburned Hydrocarbon (UHC) emissions by 22.91% and 12% correspondingly compared with other blends. The above results demonstrated the optimal improvement in whole engine performance characteristics and fewer environmental pollutants at a dosage level of 60 ppm TiO2 nano particles.

Effect of injection parameters on combustion and emission characteristics under catalyst heating operation in a direct-injection spark-ignition engine

Clean and stable operation during the catalyst heating mode in a direct-injection spark-ignition engine is crucial to meet increasingly stringent emission regulations. Although the injection strategy has a profound effect on both emission and combustion characteristics, the relative importance of various injection parameters is not well understood under catalyst heating operation. Consequently, a parametric sweep of injection timing, injection pressure, and a number of split injections was conducted to reveal the relative impact of each parameter on particulate emissions, unburned hydrocarbon emissions, and combustion characteristics. A single-cylinder research engine with a side-mounted multi-hole injector was used in the experiments. The fuel was injected during the early intake stroke with 2–4 split injections using 10 and 20 MPa of injection pressure. Retarding the injection timing had the most significant influence on the accumulation-mode particulate emission. However, combustion stability can deteriorate if the injection timing is retarded beyond a certain point, possibly because of unfavorable fuel distribution near the spark plug. The higher number of split injections and/or injection pressure also contributed to lower accumulation-mode particulates. However, the combination of higher injection pressure and split numbers led to increased combustion variability due to the injector operating in a ballistic regime. The unburned hydrocarbon emissions were found to be insensitive to the injection parameters. Utilizing the parametric sweep results, it was hypothesized that the curtailment of the amount of fuel injected while the piston is located closer to the injector tip contributes to a lower fuel film on the piston surface and hence reduces engine-out particulate emissions. The estimation of fuel films using three-dimensional computational fluid dynamics confirmed that the hypothesis is valid under the catalyst heating operation used in this study. In the last step, the split ratio was varied such that the injection duration per injection increased gradually. Such a split ratio enabled further reduction of particulate emissions without incurring a penalty in unburned hydrocarbon emissions and combustion stability.

Experimental studies of an LHR mode DI diesel engine run on antioxidant doped biodiesel

In this research work, N, N'-Diphenyl-p-phenylenediamine (DPPD) as an antioxidant at various concentrations as 500, 1000, 1500, and 2000 ppm is dosed with Jatropha methyl ester (JME). The mixtures are tested in a naturally aspirated, constant speed, compression ignition (CI) engine. Yttria stabilized zirconia (YSZ), is coated on the piston crown of the test engine for converting it to a low heat rejection (LHR) engine. The engine characteristics in terms of combustion, emission, and performance of TBC piston-fitted engine run on antioxidant doped JME are evaluated at all engine loads. The experimental results are obtained for running the engine on the antioxidant doped JME conventional and LHR modes. By running the engine on antioxidant doped JME in the LHR mode, the heat release rate and the peak cylinder pressure rise by about 4.9% and 7.8%, respectively, at the maximum load condition. The carbon monoxide (CO) and unburned hydrocarbon (HC) emissions reduce to a maximum of 10.1% and 13.3%, serially, at maximum load operation; meanwhile, nitric oxide (NO) emission decreases by 13.6% at full load. The fuel consumption and thermal efficiency of the LHR engine improve by about 7.9% and 11.3%, respectively, at full load. The smoke opacity of the engine is decreased by about 8% at full load. All the obtained results are discussed in this research article.

A novel method to overcome the shortcomings of turbocharging a single cylinder diesel engine

Single-cylinder diesel engines are generally not turbocharged because of highly pulsating exhaust gas flow, resulting in increased speed fluctuations and reduced turbine performance. In the present work, a novel and simple method is proposed wherein an exhaust plenum is placed before the turbine to reduce the flow fluctuations. A production light-duty naturally aspirated (NA) diesel engine modified into the turbocharged version was incorporated with an exhaust plenum. Steady-state experiments were performed with the base naturally aspirated engine, the turbocharged version without an exhaust plenum (conventional pulse turbocharging), and the turbocharged version with the exhaust plenum. The present work attempts to establish the limitations of conventional pulse turbocharging in a single-cylinder diesel engine unavailable in the existing literature. Though the conventional pulse turbocharged version could deliver a boost pressure of about 2 bar (absolute), a brake power reduction of 40% and the associated drop in brake mean effective pressure was observed compared to the base NA engine due to high exhaust back pressures. The pumping work was four times higher in conventional pulse turbocharging than the NA engine, thus reducing the performance. After validating the simulation models, a one-dimensional simulation tool was used to evaluate the effect of incorporating exhaust plenum before the turbine. Simulated results predicted the brake power output within a 3% error for the NA and plenum turbocharging configurations. An optimal plenum volume was arrived at using the validated simulation model. Subsequent experiments on the turbocharged engine with the plenum in place showed a significant improvement in the engine performance and reduced exhaust emissions compared to the NA version. Brake power output was enhanced by 25%, which indicated improved thermal efficiency of 2%. Compared to the NA version, the soot, carbon monoxide (CO) and unburned hydrocarbon HC emissions were reduced by 93%, 88%, and 53%, respectively. However, an increase in oxides of nitrogen (NOx) emissions was seen, which can be controlled with suitable mitigation methods taking advantage of the significantly lower soot levels. Thus, the proposed method of placing an exhaust plenum before the turbine makes turbocharging viable on single-cylinder diesel engines with performance improvement and emission reduction when suitable NOx mitigation measures are adopted.

Effect of low CeO2 nanoparticles dosage in biodiesel-blends on combustion parameters and toxic pollutants from common-rail diesel engine

The effect of toxic pollutants and combustion parameters from six-cylinder turbocharged common-rail diesel engine fueled with low CeO2 nanoparticles dosage in biodiesel blends were investigated. Experiments were examined with four different test fuels under 50% engine load at a constant speed of 1800 rpm. The results indicated that the B15C15 significantly improves the in-cylinder pressure and heat release rate compared to other test fuels. In comparison with B0, the result showed a significant reduction in CO and HC emissions for biodiesel-CeO2 blend fuels, along with a slight increase in NOx ranges between 2.78% and 19.01%. This reduction in unburned hydrocarbon inhibits the peak changes from nucleation mode to accumulation mode. In the meantime, accumulation mode particles decrease and the peak moves to the small particle size. Besides, B15C15 had a positive impact on organic compounds, which resulted in a 64.7% reduction of PAH emissions compared to B0. Whereas the emission factors of n-alkane such as dodecane, tetradecane and hexadecane, showed a negligible amount. However, the significant reduction of the respective concentration of OC and EC suggests that these compounds are either not formed as readily in combustion, or they are reduced effectively with biodiesel-CeO2 blend fuels.

Performance and emission modeling of a 4-stroke diesel engine with biodiesel extracts from waste cooking oil blends with ZnO nanoparticle using ELM

This research article provides the artificial neural network (ANN) model developed to predict the performance and emission behaviour of 4-stroke single cylinder diesel engine with biodiesel extracts from waste cooking oil blends prepared by transesterification method with ZnO nanoparticle in bimodal fuel. The ANN model was developed to predict the brake thermal efficiency (BTE), Brake-specific fuel consumption (BSFC), carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxide (Nox) and un-burnt hydro carbons (UBHC) under the heterogeneous load conditions, biodiesel and NP content. An efficient learning algorithm namely extreme learning machine (ELM) algorithm is used for predicting performance and emissions characteristics. It was found that mean square error (MSE) of 0.00128 with 15 hidden neurons converging in 0.00452 s.

Influence of injection timing on performance and combustion characteristics of compression ignition engine working on quaternary blends of diesel fuel, mixed biodiesel, and t-butyl peroxide

The objective of the present work is to examine the effects of adding t-butyl peroxide (TB) additive with diesel fuel and biodiesel originated from Mahua oil and waste Palm oil in form of quaternary blends with varying injection timing (21obTDC (before Top Dead Centre), 23obTDC, and 25obTDC) on performance, emission, and combustion characteristics of a diesel engine. In this experimentation, all the quaternary blends were prepared by keeping the volume percentage of diesel fuel at 50% v/v, while concentrations of Mahua oil-based biodiesel, waste Palm oil-based biodiesel, and t-butyl peroxide were varied by volume. The prepared blends were utilized on a constant-speed single-cylinder 4-stroke turbocharged diesel engine for comprehensive analysis in contrast to diesel fuel. The obtained results depicted that the quaternary blend of 50% diesel fuel (D)/20% mixed biodiesel (MB)/30% t-butyl peroxide (TB) (D50-MB20TB30) at advanced injection timing of 25°bTDC has shown a 2.66% increment in exhaust gas temperature and a 2.12% reduction in brake thermal efficiency compared to diesel fuel. At peak load, emission parameters such as carbon monoxide, unburnt hydrocarbon, and smoke opacity for D50-MB20TB30 were found to be respectively 4.59%, 3.47% and 5.03% lower than those of diesel fuel, although there was a slight increment by 0.83% of nitrogen oxide compared to diesel fuel. Considering combustion behaviours, heat release rate, cylinder pressure, and ignition delay were also observed to be 1.14%, 2.21%, and 8.34% lesser than conventional diesel fuel at 100% load, respectively. In closing, using the D50-MB20TB30 quaternary blend combined with advanced injection timing of 25°bTDC could offer a significant efficiency in improving the engine performance and reducing pollutant emissions, contributing to sustainable development and environment protection.

Investigating realistic anode off-gas combustion in SOFC/ICE hybrid systems: mini review and experimental evaluation

Solid oxide fuel cells (SOFCs) have been deployed in hybrid decentralized energy systems, in which they are directly coupled to internal combustion engines (ICEs). Prior research indicated that the anode tailgas exiting the SOFC stack should be additionally exploited due to its high energy value, with typical ICE operation favoring hybridization due to matching thermodynamic conditions during operation. Consequently, extensive research has been performed, in which engines are positioned downstream the SOFC subsystem, operating in several modes of combustion, with the most prevalent being homogeneous compression ignition (HCCI) and spark ignition (SI). Experiments were performed in a 3-cylinder ICE operating in the latter modus operandi, where the anode tailgas was assimilated by mixing syngas (H2: 33.9%, CO: 15.6%, CO2: 50.5%) with three different water vapor flowrates in the engine’s intake. While increased vapor content significantly undermined engine performance, brake thermal efficiency (BTE) surpassed 34% in the best case scenario, which outperformed the majority of engines operating under similar operating conditions, as determined from the conducted literature review. Nevertheless, the best performing application was identified operating under HCCI, in which diesel reformates assimilating SOFC anode tailgas, fueled a heavy duty ICE (17:1), and gross indicated thermal efficiency ([Formula: see text]) of 48.8% was achieved, with the same engine exhibiting identical performance when operating in reactivity-controlled compression ignition (RCCI). Overall, emissions in terms of NOx and CO were minimal, especially in SI engines, while unburned hydrocarbons (UHC) were non-existent due to the absence of hydrocarbons in the assessed reformates.