Increase In Nitrogen Oxides Emissions Research Articles

Study on the Effect of Parameter Sensitivity on Engine Optimization Results

The effects of six control parameters, intake valve opening timing (IVO), exhaust valve opening timing (EVO), compression ratio (CR), engine speed, intake temperature, and intake pressure on engine output power, indicated specific fuel consumption (ISFC), and nitrogen oxides (NOx) emissions, are analyzed through engine simulation. The six parameters were categorized into two groups based on the degree of influence: high influence (EVO, speed and intake pressure) and low influence (CR, IVO and intake temperature). The relationship between these two groups of parameters and power, ISFC and NOx emissions was explored. Optimization was carried out for each of the two groups of parameters, and the optimization of the high impact parameters resulted in a higher diversity and wider distribution of the solution set. On the other hand, the optimization of the low-impact parameters resulted in a more concentrated distribution of the solution set, while better reflecting the trade-off between the optimization objectives. For the optimal solutions for both sets of parameters, the high-impact parameters provided significant optimization performance compared to the standard operating conditions. Although power and ISFC were optimized, the optimal solution for the low-impact parameter performed poorly with a significant increase in NOx emissions. Therefore, the parameters should be evaluated for optimization using high impact parameters to improve engine performance.

Preliminary assessment of the potential for rapid combustion of pure ammonia in engine cylinders using the multiple spark ignition strategy

In pursuit of carbon neutrality, the adoption of zero-carbon fuels in internal combustion engines offers a path to zero carbon emissions. Among such fuels, ammonia (NH3) stands out as an effective hydrogen energy carrier with a higher energy density and a more advanced production-storage-transportation lifecycle than hydrogen (H2) fuel, making it a superior alternative. Nevertheless, achieving high combustion efficiencies in engine cylinders requires the use of fuels with fast flame speeds, since the time scales of the combustion event are practically milliseconds. The inherent flame speed of NH3 falls short, typically necessitating augmentation with H2. Yet, the in-situ generation of H2 from NH3 remains constrained, rendering the flame speed of NH3 less competitive against traditional fuels like gasoline and natural gas. To address the dual challenges of slow flame speed of NH3 and the difficulty of generating large amounts of H2 from NH3 onboard, this study evaluates an alternative method of accelerating the ammonia combustion in the engine combustion chamber through the use of multiple spark plugs, which is limited discussed in existing research. Numerical simulations performed in this study show that the application of the multi-spark strategy increases the mass burn rate, advances the combustion phasing, shortens the combustion duration, increases the engine power output, improves the fuel economy, and reduces the unburned ammonia emissions, all of which indicate that rapid combustion of pure ammonia is achieved in the combustion chamber. Moreover, the use of multiple spark points does not lead to a marked increase in nitrogen oxides emissions, thereby ensuring no added stress on exhaust aftertreatment systems. In addition, pure ammonia combustion appears to be very well adapted to this strategy, as evidenced by the avoidance of excessive cylinder pressures and pressure rise rates—a challenge faced by conventional spark ignition engines, given ammonia notably slower flame speed relative to conventional petroleum-based fuels. Overall, all these findings strongly support that the multi-spark ignition system presents a compelling direction for future zero-carbon ammonia engines. However, it is crucial to address design challenges to ensure that the engine head layout provides sufficient cooling, structural robustness, optimal breathing efficiency, and reliable multi-ignition events within the confined space.

Effect on minor addition of aromatic (benzyl alcohol) and diethyl ether in Calophyllum inophyllum blended diesel fuel in a CI engine operates by hydrogen energy as a secondary fuel

Strict regulations on vehicle emissions are in place to lessen pollution and environmental damage. The depletion of fossil fuels also threatens energy security. Renewable, cleaner-burning and sustainable fuels could aid the researcher in solving these problems. Because of their limited supply, renewable fuels cannot resolve the issue independently. Therefore, much research is being done on enhanced combustion technologies, such as dual-fuel engines, homogenous charge compression ignition, and low-temperature combustion. The Calophyllum inophyllum oil (P20) mixed with diesel, diethyl ether, and aromatic alcohol (benzyl alcohol) was tested in this study using a dual-fuel engine. Hydrogen gas is added to the air intake manifold as a second energy source. Aromatic alcohol is an organic fuel that can be produced naturally by hydrolysis of lignin. The OH hydroxyl group is attached to the aromatic ring and promotes free radical propagation. Minor addition of oxygenates affects the performance, combustion, and emission of engines operating on various loads. Maximum brake thermal efficiency and lower brake-specific fuel consumption were observed with 20 % aromatic alcohol, 32.45 %, and 0.2 kg/kW-hr, respectively. Brake thermal efficiency improved to 6.54 % compared to neat diesel. Reduction in brake-specific fuel consumption by 28 % compared to diesel fuel. Compared to other blends, aromatic alcohol additions are linked to reduced smoke, HC, and CO emissions. However, using aromatic alcohol results in slightly increased nitrogen oxide emissions compared to diesel. Blends of biofuel and benzyl alcohol have shown favorable effects in terms of enhanced combustion, reduced emissions, and increased efficiency.

Experimental Analysis of Hydrogen Enrichment in Waste Plastic Oil Blends for Dual-Fuel Common Rail Direct Injection Diesel Engines

Abstract Growing global concerns about fossil fuels highlight the importance of alternative fuels for internal combustion engines. Proper management of plastic waste is crucial due to its environmental impact. The pyrolysis oil process offers a sustainable solution to address plastic waste accumulation. This study explores the impact of a hydrogen-waste plastic oil blend on a modern diesel engine. Blends of diesel and plastic oil in ratios of 90:10, 80:20, and 70:30, with hydrogen supplied at 8 liters per minute, are investigated. Experiments are conducted at various loads, and hydrogen-enriched fuel blends are analyzed for combustion characteristics, performance parameters, and emissions. Higher blended fuel ratios lead to extended ignition delays, decreased thermal efficiency, and increased emissions. Hydrogen enrichment reduces carbon dioxide, hydrocarbon, and carbon monoxide emissions, but raises nitrogen oxide emissions due to higher exhaust gas temperatures. The comparative analysis shows significant improvements in brake thermal efficiency and brake-specific fuel consumption under full load conditions. The blend demonstrates notable reductions in hydrocarbon, carbon monoxide, and carbon dioxide emissions, but an increase in nitrogen oxide emissions compared to diesel. The findings indicate that integrating hydrogen into diesel engines enhances performance measures and reduces overall emissions.

Performance and Emission Analysis of Biodiesel Blends in a Low Heat Rejection Engine with an Antioxidant Additive: An Experimental Study.

The rapid depletion of crude oil and environmental degradation necessitate the search for alternative fuel sources for internal combustion engines. Biodiesel is a promising alternative fuel for compression ignition (CI) engines due to its heat content and combustion properties. Biodiesel blends are used in various vehicles and equipment, such as cars, trucks, buses, off-road vehicles, and oil furnaces. Biodiesel can reduce emissions from CI engines by up to 75% and improve engine durability due to its high lubricity. However, biodiesel has some drawbacks, including a performance reduction and increased nitrogen oxide emissions. Therefore, this study aims to investigate using environmentally available biodiesel in a low-heat rejection engine and an antioxidant additive to enhance the performance and reduce nitrogen oxide emissions. India currently has several biodiesel sources, including mango seed oil, mahua oil, and pongamia oil, which can be effectively utilized in CI engines by adding l-ascorbic acid. The experimental work involves a single-cylinder 4-stroke water-cooled direct injection CI engine with a power output of 5.2 kW. The engine's cylinder head, piston head, and valves are coated with lanthanum oxide using the plasma spray coating technique, with a thickness of 0.5 mm. The coated and uncoated engines are tested with different proportions of mahua oil, mango seed oil, and pongamia oil. The results show that the engine's performance is significantly improved compared to the baseline engine at all loads. Additionally, these biodiesels exhibit a notable reduction in nitrogen oxide emissions when combined with l-ascorbic acid.

Emission Measurements on a Large Sample of Heavy-Duty Diesel Trucks in China by Using Mobile Plume Chasing.

Real-world heavy-duty diesel trucks (HDTs) were found to emit far more excess nitrogen oxides (NOX) and black carbon (BC) pollutants than regulation limits. It is essential to systematically evaluate on-road NOX and BC emission levels for mitigating HDT emissions. This study launched 2109 plume chasing campaigns for NOX and BC emissions of HDTs across several regions in China from 2017 to 2020. It was found that NOX emissions had limited reductions from China III to China V, while BC emissions of HDTs exhibited high reductions with stricter emission standard implementation. This paper showed that previous studies underestimated 18% of NOX emissions in China in 2019 and nearly half of the real-world NOX emissions from HDTs (determined by updating the emission trends of HDTs) exceeded the regulation limits. Furthermore, the ambient temperature was identified as a primary driver of NOX emissions for HDTs, and the low-temperature penalty has caused a 9-29% increase in NOX emissions in winter in major regions of China. These results would provide important data support for the precise control of the NOX and BC emissions from HDTs.

Effects of metal oxides on reducing NOx emissions from the combustion of Pennisetum giganteum at various temperatures and oxygen concentrations in a Tubular Furnace

Pennisetum giganteum (P. giganteum) is a popular biomass raw material with a fast growth rate and high yield. Herein, a tube furnace device is used to analyze the effects of temperature, oxygen concentration, and type and mass fraction of metal oxide, upon the combustion of P. giganteum in order to determine the optimal conditions for controlling the release of nitrogen oxides (NOx). The results demonstrate a 261.17% increase in NOx emissions from 1.03 × 10-4 L/g to 3.72 × 10-4 L/g as the temperature is increased from 600 to 900 °C. Meanwhile, as the oxygen concentration is increased, the NOx emissions initially increase, and eventually stabilize. Finally, The type and mass fraction of metal oxide has a significant impact on NOx emissions. Overall, all the four metal oxides (CaO, Fe2O3, TiO2, and Al2O3) can inhibit NOx emissions, with Fe2O3 having the best effect, giving a 24.3% reduction at a mass fraction of only 5%. Moreover, the composite metal oxides Fe2TiO5, Fe2TiO5-Al2O3, and Fe2TiO5-CaO are shown to significantly reduce NOx emissions, with Fe2TiO5 having the best effect, of emission reduction rate of 29.67%, which is 5.34% and 16.32% higher than single metal oxides Fe2O3 and TiO2, respectively.

Experimental study of a dual-fuel spark-assisted compression ignition engine with polyoxymethylene dimethyl ether and methanol as fuels

Polyoxymethylene dimethyl ethers (PODE) and methanol are promising alternative fuels for internal combustion engines, offering emission reduction and compatibility with existing engine combustion technologies. They can be chemically synthesized, providing a renewable and clean energy source for sustainable transportation. Additionally, dual-fuel spark-assisted compression ignition (SACI) is an advanced combustion mode that offers precise control of the combustion. However, there is limited research on dual-fuel SACI based on PODE and methanol, and the understanding of its multi-stage combustion, the cross-effects of multiple parameters, and the transition between ignition and compression ignition are still unclear. In this study, a modified gasoline engine was used to investigate the combustion characteristics of a dual-fuel SACI engine. The engine was fueled with direct injection PODE and port injection methanol. The combustion process was examined with a focus on the cooperative control of multiple parameters. The effects of the mass ratio of PODE, spark ignition timing, and start of injection timing were analyzed. The results demonstrated the presence of multiple heat-release stages during dual-fuel SACI combustion, involving both compression ignition and flame propagation ignition. An optimal interval between the start of injection timing and spark ignition timing was observed, leading to high brake thermal efficiency. This interval facilitated the formation of a highly reactive mixture during ignition, enabling efficient ignition of methanol by PODE. At a brake mean effective pressure of 0.8 MPa, a brake thermal efficiency of 44% was achieved with a 75% methanol ratio. Additionally, by appropriately increasing the mass ratio of PODE and advancing the start of injection timing, a significant reduction in hydrocarbon emissions was observed, albeit with a slight increase in nitrogen oxide emissions. These findings provide support for low-carbon operation of engines.

Nanoparticles as Additive to the Diesel and Biodiesel along with Blends: A Review on Emission Characteristics and Performance of CI Engine

The depletion rate of fossil fuels are very high as well as they put negative impact on the environment. So the alternate fuels are required to meet the demand of the world. The bio based fuels and blends are the source which can be help for the sustainable development. The mild negatives of biodiesel, like its increased nitrogen oxide emissions, inconsistency with winter conditions, and frequent replacement cycles for engine parts like fuel filters, fuel tanks, and fuel lines owing to clogging, exceed its many advantages. By using nanoparticles as fuel additives, there is still room to improve the qualities of fuel and address its shortcomings. The role of nanoparticles additives increases the thermos-physical properties of the pure fuel, bio based fuel and blends. They directly affect how well the diesel engine performs. There are various nanoparticle additions that play diverse roles in the operation and emission process of the diesel engine. The common nanoparticles additives such as cerium oxide, aluminium oxide, magnesium, carbon nano tubes are the common additives which are directly used. This review article analyses the performance, emission traits, fuel characteristics, and issues with the nanoparticle additions. Additionally, this work aids researchers in their investigation of potential nanoparticle additions in the future.

Rapid increase in tropospheric ozone over Southeast Asia attributed to changes in precursor emission source regions and sectors

Observations indicate that tropospheric ozone (O3) concentrations over Southeast Asia have been increasing rapidly since the 1990s. Here, we quantify source contributions from geographical regions and emission sectors of the two distinct types of O3 precursors, i.e., nitrogen oxides (NOx) and volatile organic compounds (VOCs), to the increase in tropospheric O3 in Southeast Asia during 1990–2019 using an O3 source tagging technique implemented in a global chemistry-climate model. The results show that although local anthropogenic emission of NOx in Southeast Asia only contributes 18% of the annual averaged near-surface O3 concentration, the increase in local NOx emission dominates the increasing trend of O3 concentration in Southeast Asia, accounting for 107% of the regional averaged trend of 1.07 ppb decade−1. Increases in NOx emissions from East Asia and South Asia explain 29% of the increasing trend, but 9% is offset by the emission reduction in North America. The vertical O3 trends in the troposphere contributed by individual source regions are consistent with those near the surface. Ground transportation is responsible for 79% of the rapid O3 increase, followed by 39% contribution from international shipping. Because an increase in anthropogenic NOx emissions enhances the O3 production efficiency by VOCs, the increase in O3 concentrations in Southeast Asia is thereby largely contributed by methane and biogenic VOCs.

Prediction of nitrogen oxide emissions from diesel exhaust gases when using composite fuel

BACKGROUND: The problem of using composite fuel (CF) in diesel engines consists in a wide variation of their physicochemical properties, which affect the emission of nitrogen oxides (NOx) with ex-haust gases (EG). Therefore, the predictive assessment of the formation of NOx with EG when using CF is very relevant.
 AIMS: Predictive assessment of quantitative NOx emission with diesel EG when using various types and compositions of CF. Scientific novelty lies in development of the method of prediction of NOx emission by a diesel engine when using CF.
 METHODS: The method of prediction of quantitative NOx emissions with diesel EG regarding the use of various CF kinds and compositions has been developed. Predictive indicators of NOx emissions have been defined. Multi-parameter characteristics of NOx emission with EG of the D-245.582 diesel engine of 4ChN 11.0/12.5 size have been obtained experimentally. Degree of convergence of the experimental data with the calculated values is assessed.
 RESULTS: As a result of the carried-out studies, it was theoretically established that the load (pe) increase from 0.2 to 1.0 MPa, the engine speed (n) decrease from 1800 to 1400 min-1 and decrease of mass fraction of rapeseed oil (RO) and ethanol (E) in CF from 40 to 20% lead to increased NOx emissions with diesel EG from 131 to 2225 ppm and from 75 to 1450 ppm respectively. The increase in NOx emissions with the EG from 152 to 2125 ppm for CF consisting of DF and RO and from 175 to 1550 ppm for CF consisting of DF and E in the above mentioned operating modes experimentally confirmed. The degree of convergence of the experimental data with the calculated values is 90.14%, which in turn indicates the possibility of using the developed methodology as a predictive indicator.
 CONCLUSIONS: As a result of the studies, it was established that the developed method of prediction of quantitative NOx emissions with diesel EG is highly likely to use for preliminary assessment when various CF kinds and compositions are considered, as the degree of convergence of the experimental data with the calculated values, assessed with a statistical processing method and experimental error calculation, is 90.14%.

Differences in phytohormone and flavonoid metabolism explain the sex differences in responses of Salix rehderiana to drought and nitrogen deposition.

Due to global warming and the increase in nitrogen oxide emissions, plants experience drought and nitrogen (N) deposition. However, little is known about the acclimation to drought and N deposition of Salix species, which are dioecious woody plants. Here, an investigation into foliar N deposition combined with drought was conducted by assessing integrated phenotypes, phytohormones, transcriptomics, and metabolomics of male and female Salix rehderiana. The results indicated that there was greater transcriptional regulation in males than in females. Foliar N deposition induced an increase in foliar abscisic acid (ABA) levels in males, resulting in the inhibition of stomatal conductance, photosynthesis, carbon (C) and N accumulation, and growth, whereas more N was assimilated in females. Growth as well as C and N accumulation in drought-stressed S. rehderiana females increased after N deposition. Interestingly, drought decreased flavonoid biosynthesis whereas N deposition increased it in females. Both drought and N deposition increased flavonoid methylation in males and glycosylation in females. However, in drought-exposed S. rehderiana, N deposition increased the biosynthesis and glycosylation of flavonoids in females but decreased glycosylation in males. Therefore, foliar N deposition affects the growth and drought tolerance of S. rehderiana by altering the foliar ABA levels and the biosynthesis and modification of flavonoids. This work provides a basis for understanding how S. rehderiana may acclimate to N deposition and drought in the future.

NOx‐Induced Changes in Upper Tropospheric O3 During the Asian Summer Monsoon in Present‐Day and Future Climate

AbstractThe upper tropospheric ozone (O3) strongly influences the atmosphere's radiative budget. Using the Aerosol and Chemistry Model Intercomparison Project simulations, we study the influence of present‐day and future anthropogenic nitrogen oxides (NOx) emissions on the upper tropospheric O3 concentrations over India during the Asian summer monsoon (ASM). We observe that the upper tropospheric O3 concentrations increased 1.5 times over the ASM anticyclone region during the ASM due to higher NOx emissions in 2014 compared to 1850, and their transport due to convection. These NOx‐induced O3 changes exert a regional positive radiative forcing of 0.6 Wm−2 at the top of the atmosphere. The upper tropospheric O3 increases in the future with increasing NOx emissions. However, air quality policies to reduce surface NOx emissions also reduce the upper tropospheric O3 over India during the ASM.

Reduction and thermodynamic treatment of NOx emissions in a spark ignition engine using isooctane and an oxygenated fuel (ethanol)

Abstract This research aims to study the effect of various blends of an alternative fuel environment (ethanol, isooctane) on the performance of a spark ignition gasoline engine. The blends were obtained from two additives: ethanol and isooctane. The tests were carried out on an engine test bench following DIN 70020. The results show that the petrol additives achieve excellent ecological results. On the other hand, the engine performance was slightly reduced compared with that obtained with pure fuel. We noted a variation in engine performance for the E10 (10% ethanol + 90% pure petrol) and I10 (10% isooctane + 90% pure petrol) blends, namely a reduction in nitrogen oxides (NOx) emissions of 7.5% for E10 and 5% for I10 compared with pure petrol. However, using E10 and I10 blends did not increase the specific fuel consumption. Thus, the increase in the octane rating resulted in a decrease in NOx emissions. The use of 96 octane fuels, which corresponds to I40 (40% isooctane + 60% petrol), is expected even though there is an 8% decrease in engine torque and a 5% decrease in power. We also noted that the blend (20% isooctane + 80% ethanol) led to a significant increase in NOx emissions, a significant increase in specific fuel consumption and a drop in performance (engine torque and power).

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.

RSM modeling of different amounts of nano-TiO2 supplementation to a diesel engine running with hemp seed oil biodiesel/diesel fuel blends

In this study, experiments were performed on a single-cylinder diesel engine to define the optimum nanoparticle ratio using the response surface methodology. The experimental fuels used were a mixture of hemp seed oil biodiesel (30% by volume) and diesel (70% by volume) mixed with titanium dioxide nanoparticles at various amounts (25, 50, 75, and 100 ppm). The addition of 100 ppm titanium dioxide increased brake thermal efficiency by 29.65% and decreased brake specific fuel consumption by 5.16%. Furthermore, the addition of titanium dioxide up to 50 ppm reduced hydrocarbon emission by 12.07%, and up to 75 ppm reduced the carbon monoxide by 40.15%. In contrast, the titanium dioxide caused an average of 27% increase in nitrogen oxide emissions. On the other hand, the optimum titanium dioxide ratio and engine load were determined as 75 ppm and 2000 W, respectively. Under these conditions, brake thermal efficiency, brake specific fuel consumption, carbon monoxide, hydrocarbon, nitrogen oxide, and smoke emissions are 27.942%, 1081.51 g/kWh, 0.057%, 40.293 ppm, 257.3742 ppm, and 0.7064%, respectively. Optimum results were achieved with an overall high desirability value of 0.7665. A good harmony among the experimental and estimated response values demonstrates the acceptability of the developed models.

Increase in nitrogen oxides due to exhaust gas recirculation valve manipulation

Exhaust gas recirculation (EGR) is a known method of reducing nitrogen oxides (NOX), but the impact of its deactivation on emissions has not been quantified. This paper, therefore, considers the impact of deactivating the EGR valve on NOX emissions in a diesel Euro 5 vehicle. The measurements were performed during nine driving cycles and in all cases, a significant increase in NOX emissions was found when the EGR valve was deactivated. NOX emissions increased between 176% and 407%, depending on the cycle driven. Measurement results indicate the origin of significant amounts of NOX emissions. Recommendations are to inform regulatory authorities about the effects of such manipulations in order to adopt more stringent measures and introduce them during periodic technical inspection of vehicles with the view to preventing such interventions.

Influence of nanoparticles on emission and performance characteristics of biodiesel-diesel blends in a DI diesel engine

ABSTRACT In this experimental work, the effects of copper oxide (CuO) nanoparticles on emissions and performance of 4.4 kW diesel engine powered by palm biodiesel were studied. Palm biodiesel of 20% by volume was blended with diesel fuel (B20). Each test fuel blend was doped with CuO nanoparticles with concentrations of 25, 50, and 75 ppm. Experimentations were carried out for 0%, 25%, 50%, 75%, and 100% engine loads at a constant speed of 1500 rpm. Different parameters, such as brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), nitrogen oxides (NOx), and smoke opacity were analysed. From the results, it is observed that by using CuO nanoparticles along with B20, BTE (1.18%-7.69%) were significantly increased and BSFC (4.12%-6.76) were lowered. Besides, by using CuO nanoparticles, there were also substantial reductions in CO (2.21%-8.86%). Furthermore, there is an insignificant increase in HC (0.3%-9.78%), CO2 (2.38%-5.97%), and NOx (1.75%-5.27%) emissions when compared to B20 blend. However, when compared to diesel fuel all the emissions were low for all biodiesel blends except NOx emission. Overall, it is concluded that CuO could be considered as a appropriate petroleum additive for palm biodiesel blends.

Biofuel from leather waste fat to lower diesel engine emissions: Valuable solution for lowering fossil fuel usage and perception on waste management

This work examines the viability of examining waste fat extracted from industrial leather waste as an alternative to diesel. These wastes are harmful if disposed to the environment. Conventional transesterification was performed to produce leather waste methyl ester (LWME). Post-processing, a yield of 82.6% of methyl ester was obtained. The obtained LWME was inspected for its thermophysical properties and falls with ASTM standards. LWME was blended with petroleum diesel at 10%, 20% and 30% on a volume basis and referred to as LWME10D90, LWME20D80 and LWME30D70 correspondingly. The effect of LWME/ diesel blends was inspected in a four-stroke, single-cylinder, direct-injection engine under diverse loads. Test results revealed that the brake thermal efficiency for LWME/ diesel blends was lower than diesel at all loads with higher specific brake-specific fuel consumption was higher as both are inversely proportional. Carbon monoxide emissions were reduced by 22.7%, Hydrocarbon emissions were reduced by 48%, and Smoke emissions were reduced by 6.43%, with a 9.84% increase in nitrogen oxide emissions for LWME30D70 than diesel. It has been concluded that including LWME in diesel lowers the greenhouse gases with a marginal reduction in performance pattern.

Effects of Propanol on the Performance and Emissions of a Dual-Fuel Industrial Diesel Engine

The search for alternative fuels that can limit the use of traditional fossil fuels to power internal combustion engines is one of the main tasks faced by both the modern automotive industry and the modern energy industry. This paper presents experimental tests of a compression ignition engine, in which the conventional fuel, i.e., diesel, was partially replaced with propyl alcohol, i.e., a renewable biofuel. Studies on the co-combustion of diesel fuel with propanol were carried out, in which the energy share of alcohol varied from 0 to 65%. The research showed that an increase in the proportion of propanol, up to 30%, resulted in a significant increase in the rate of heat release and the rate of pressure increase in the cylinder of a compression-ignition engine. Increasing the alcohol content to 65% resulted in an increase in the ignition delay time and significantly shortened the duration of combustion. During the combustion of diesel fuel with a 50% propanol share, the engine was characterized by maximum efficiency, higher than diesel fuel combustion by 5.5%. The addition of propanol caused a slight deterioration of the combustion stability determined by the coefficient of variation for IMEP. The study of engine exhaust emissions has shown that the combustion of diesel fuel with a small proportion of propanol, up to 30%, causes an increase in nitrogen oxide emissions, while up to 50% contributes to a decrease in HC emissions. The increased share of alcohol contributed to a significant decrease in the emissions of both carbon monoxide and carbon dioxide, and caused a significant reduction in the concentration of soot in the exhaust of the compression-ignition engine.