Decrease In Hydrocarbon Emissions Research Articles

Engine Behavior Analysis on a Conventional Diesel Engine Powered with Blends of Lemon Grass Oil Biodiesel–Diesel Blends

<div>Fossil fuel usage causes environmental pollution, and fuel depletion, further affecting a country’s economy. Biofuels and diesel-blended fuels are practical alternatives to sustain fossil fuels. This experimental study analyses lemongrass oil’s performance, emissions, and combustion characteristics after blending with diesel. Lemongrass oil is mixed with diesel at 10 (B10), 15 (B15), and 25% (B25) and evaluated using a 5.20 kW direct injection diesel engine. B10 brake thermal efficiency is 36.47%, which is higher than other blends. The B10 displays an 8.73% decrease in brake-specific fuel consumption compared to diesel. An increase in exhaust gas temperature for B10 than diesel is 4.5%. It indicates that higher lemongrass oil blends decrease exhaust gas temperature. The decrease in average carbon monoxide emissions in B10 to diesel is 22.19%. The decrease in hydrocarbon emissions for B10 to diesel is 7.14%. Biodiesel with lemongrass oil increases nitrogen oxide (NOx) because of increased temperature and poor combustion. Apart from NOx emissions, all other parameters of lemongrass oil blends are suitable for practical diesel applications. The significant findings benefit the biodiesel community toward the efficient combustion of biodiesel blends.</div>

Experimental probe into an automative engine run on waste cooking oil biodiesel blend at varying engine speeds

The present work attempts to evaluate the performance of an automotive diesel engine run on waste cooking oil biodiesel (WCO) blend at variable engine speeds. The composition of the blend (B40) used in the study is 40% WCO and 60% diesel by volume and the engine used for the experimentation is a naturally aspirated, water-cooled and direct injection type having a compression ratio of 18:1. The engine settings used in the study are an injection timing (IT) of 150bTDC and a fuel injection pressure (IP) of 500 bar. The performance and emissions characteristics of the automotive engine are studied at various loads of 20%, 40%, 60%, 80% and 100% and at different engine speeds of 1500, 1800 and 2400 rpm. The first two rotational speeds are chosen to study the stationary power generation capabilities of the blend, while the feasibility of blend for automotive applications has been evaluated at 2400 rpm. Experiments have also been conducted on the engine run on mineral diesel fuel in order to make a comparative analysis. At full load, the maximum brake thermal efficiency (BTE) is found to be 21.51%, 25.48% and 23.56% for the blend at 1500, 1800 and 2400 rpm, respectively. At 2400 rpm and at 20% and 40% loads, the blend shows an absolute improvement in BTE of 0.17% and 0.03%, respectively over diesel fuel. On an average, there is a decrease of carbon monoxide (CO) emissions by 87.5%, 22.22% and 14.28% at 1500, 1800 and 2400 rpm as compared to diesel fuel. At 1500 and 2400 rpm, there is an average absolute increase in hydrocarbon (HC) emissions by 1.6 ppm and 9.6 ppm, respectively; while at 1800 rpm, an average decrease in HC emissions by 4 ppm is observed vis-a-vis diesel fuel. While emissions of oxides of nitrogen (NOx) as compared to diesel fuel increased on an average by 19.43%, 26.09% and 1.01% at 1500, 1800 and 2400 rpm, respectively.

Покращення показників автомобільних дизельних двигунів при додаванні водневої каталітичної добавки

The aim of the study is to present a new proposed method for improving the efficiency of transportation diesel engines. Considering the rising cost of transportation, where 80% of the expenses are attributed to fuel costs, there is a necessity to develop methods for reducing fuel consumption. Among the main approaches are the use of alternative fuels or fuel additives. One of the most effective and promising options is the utilization of hydrogen, both as an alternative fuel and a fuel additive. Among the crucial factors significantly influencing the efficiency of hydrogen additives is the method of their delivery to the internal combustion engine. Injecting hydrogen during the engine's intake stroke, although a simple method, faces challenges in achieving precise engine control and poses risks due to the potential formation of an explosive mixture in the intake tract and subsequent ignition. A proposed solution involves introducing small hydrogen additives into the high-pressure fuel line, between the fuel pump and the injector. After the completion of the injection process in the high-pressure line, a "rarefaction wave" is generated. Utilizing this effect allows introducing a small amount of hydrogen into the diesel fuel. Hydrogen delivery is ensured by a special device equipped with a check valve that reacts to changes in pressure in the fuel line. Hydrogen, when introduced into the fuel, promotes improved combustion and increased engine efficiency. This results in a reduction in fuel consumption by 0.4 to 3.5% compared to nominal values, with particularly high fuel efficiency observed at partial load conditions, as well as during acceleration and maneuvers. It is worth noting the positive environmental impact of this technology. When adding hydrogen in a proportion of 0.1% of the fuel mass, a decrease in hydrocarbon emissions by 40–50% and carbon monoxide by 15–25% is observed. However, an increase in nitrogen oxide emissions by 3–7% has been identified, which is associated with a certain elevation of the maximum cycle temperature. Nevertheless, NOx emissions increase can be mitigated by implementing appropriate adjustments to the engine's operating parameters.

Study of the performance and emissions of diesel engines operating by blends of Jatropha biodiesel, diesel and pentanol

Nowadays fossil fuels have become very expensive and polluting it is therefore necessary to look for an alternative fuel which is biodiesel which had recently become one of the promising fuels. The present aim of this work is to experiment with a compression ignition engine using jatropha blended with diesel and pentanol as an additive in different ratios. The present experiment is carried out in a constant-speed, direct-injection, water-cooled engine at different loads with eight different blends. The blends are prepared as follows: Jatropha25Diesel75Pentanol10, J50D50P10, J25D75P10, J100P10, J25D75P15, J50D50P15, J75D25P15, J100P15 and are tested in a diesel engine. The experimental results show that there is a 1.28 % increase in engine efficiency, a 10 % increase in nitric oxide emissions, a 22.35 % decrease in smoke opacity and a 22.58 % decrease in hydrocarbon emissions compared to base fuel.

Investigation of the impacts of gasoline, biogas and LPG fuels on engine performance and exhaust emissions in different throttle positions on SI engine

In this study, experiments have been carried out with the use of gasoline, liquified petroleum gas (LPG), and biogas fuels in different volumetric percentages in a single cylinder, four strokes, spark ignition (SI) engine with different throttle position. In experiments, data were compared which were obtained by using gasoline, biogas and LPG; brake thermal efficiency (BTE), cylinder pressures, mean gas temperature (MGT), brake specific fuel consumption (BSFC), carbon dioxide (CO2), carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NOx) emissions. According to the results, with the use of biogas and LPG in the full throttle opening (FTO), a 75.52% and 34.19% increase in the BSFC was determined compared to the use of gasoline, while a 16.04% and 8.95% reduction in the BTE was determined. On the other hand, with the use of biogas and LPG, a decrease of 15% and 62.03% in CO emissions, 23% and 63% decrease in HC emissions, 6.77% and 56.42% decrease in CO2 emissions were detected compared to gasoline. In the half throttle opening (HTO), BSFC increased by 85.2% and 45.51%, while BTE decreased by 33.43% and 20.22%. In addition, a decrease of 15.97% and 47.65% on CO emissions, 21.19% and 62.38% HC emissions, 6.84% and 69.54% CO2 emissions were detected. In terms of cylinder pressure value, with biogas and LPG, cylinder pressures decreased about 17.76% and 24.41%, respectively. On the other hand, compared to the gasoline, MGT increased with the use of LPG and decreased by the usage of biogas.

Experimental study on an SI engine fuelled by gasoline/acetylene mixtures

Internal combustion engines that are widely used as a power source in passenger and freight transport, individual transport vehicles, agricultural sector, fixed and mobile generators, are dependent on fossil fuels, especially oil. However, decrease in the oil reserves and environmental problems such as the global warming have compelled researchers to search for alternative fuels for internal combustion engines. In this study, the effects of the use of gasoline and acetylene mixtures on the overall performance of a spark ignition (SI) engine have been experimentally investigated. Experiments have been carried out on a four-stroke, four-cylinder, water-cooled SI engine and at stoichiometric conditions. Acetylene flow rates were fixed at 500 g/h and 1000 g/h in these experiments. The performance and emission parameters were studied by changing the load from 25% to the full load. The maximum acetylene content of the gasoline-acetylene mixture was 54% at 25% load, while this rate was 22.4% at the full load. Acetylene induction resulted in lower thermal efficiency at almost all loads. A decrease in hydrocarbon emissions was observed at all engine loads while NO emissions increased at low loads when compared to that of gasoline.