Exhaust Gas Emissions Research Articles

Impact of fuel starvation–induced anode carbon corrosion in proton exchange membrane fuel cells on the structure of the membrane electrode assembly and exhaust gas emissions: A quantitative case study

Although the durability of proton exchange membrane fuel cells (PEMFCs) is crucial for their broad commercial applications, current durability assessments do not encompass all operational scenarios. Startup/shut-down (SUSD) are among the most significant degradation factors in the city. To bridge this gap, we examine the phenomenon of fuel starvation, which leads to the rapid and irreversible degradation of PEMFC performance, particularly during SUSD, but has not been independently examined in the context of PEMFC durability. A quantitative methodology is used to analyze anode carbon corrosion and establish correlations with critical parameters under fuel starvation conditions. In particular, we quantify carbon loss based on (i) the composition or amount of the anode outlet gas emitted under such conditions and (ii) changes in the anode thickness at three distinct locations. The corresponding carbon losses due to 10 min of fuel starvation ((i): 212.0 μg cm−2, (ii): 189.6 ± 12.9 μg cm−2) agree well with each other. The largest decrease in the anode thickness (81.3 %) is observed near the outlet. The obtained insights provide guidance for the design of high-performance PEMFCs and the development of protective measures against the detrimental effects of fuel starvation.

Suitability of Hybrid Passenger Vehicles in Metropolitan Cities: A Study of Paris and Cairo Using Toyota Prius

Abstract Hybrid electric vehicles (HEVs) reduce metropolitan city air pollution and traffic congestion. This paper evaluates the performance of the Toyota Prius, a passenger HEV model, in Paris and Cairo, using driving cycle data incorporated in the validated digital tool (Advanced Vehicle Simulator - ADVISOR ). The paper compares exhaust gas emissions and fuel consumption of the selected HEV in those two cities. The results show a reduction in exhaust gas emissions and fuel consumption in Paris than in Cairo and a significant reduction in greenhouse gas emissions. The paper suggests that the HEV Toyota Prius is a suitable and sustainable solution for urban transportation in metropolitan cities.

Investigation of the Effect of TiO2 Nanoparticles on Engine Performance and Emission Characteristics in Diesel Engines

This study aimed to examine the changes in performance and emission values in a four-stroke and three-cylinder diesel engine by using pure diesel fuel and fuels created by adding TiO2 nanoparticles. Adding TiO2 nanoparticles to the fuel aimed to improve the combustion characteristics of the diesel engine and reduce the harmful effects of exhaust emissions. Pure diesel and TiO2 nanoparticle added fuel samples in three distinct amounts, 25 ppm, 50 ppm, and 75 ppm, were prepared in magnetic and ultrasonic mixers as D100, D100+25TiO2, D100+50TiO2, and D100+75TiO2. All fuel samples used in the research were tested at a constant speed of 1800 revolutions per minute (rpm) at 25%, 50%, 75%, and 100% full loads. When TiO2-added fuels were compared to pure diesel, there was a 15.12% rise in brake thermal efficiency at %25 load and a 13.36% drop in brake specification fuel consumption at %25 load. EGT values also increased with the increase in load and adding TİO2. The amount of CO2 in exhaust emissions increased by 5% at maximum load in the fuel with the highest TiO2 additive according to neat diesel. There was an average increase of 11.44% in NOX emissions for all loads with TiO2 addition. The results show that the fuel mixture created by adding TiO2 nanoparticles can be used in certain proportions in diesel engines and that the TiO2 addition positively improves the combustion properties, engine performance, and exhaust gas emissions.

Monitoring CO2 and SO2 Exhaust Gas Emissions on Tanker Ships With An IoT Based PLC Controller

Monitoring CO2 and SO2 Exhaust Gas Emissions on Tanker Ships With An IoT Based PLC Controller

Prediction of Fuel and Exhaust Emission Costs of Heavy-Duty Vehicles Intended for Gas Transportation

This research focuses on heavy-duty vehicles intended to transport compressed natural gases, i.e., class-2 dangerous goods. The analysis includes heavy-duty vehicles powered by diesel and compressed natural gas and trailers with two body types. The body types used in the research are battery bodies and multiple-element gas containers, with pressure vessels made of composite materials (Type-4) and steel (Type-1). The paper presents the methodological procedure for predicting fuel and exhaust gas emission costs as a function of fuel consumption and transported gas quantities. The effects of different types of bodies and different types of fuel on the transported quantities of gas, vehicle mass utilization, fuel consumption, and exhaust gas emissions are shown. The obtained results show that bodies with Type-4 pressure vessels transport 44% more gas than bodies with Type-1 pressure vessels for one turn. The most cost-effective solution for emission costs is diesel-powered, newer-technology vehicles and Type-4 vessels, requiring EUR 2.82 per ton of gas. Similarly, the most economical choice for fuel costs is compressed natural-gas-powered vehicles with Type-4 bodies and a cost of EUR 19.77 per ton of gas. The research results’ practical application pertains to the selection procedures of vehicles and bodies intended for the transport of gases; they should be considered in the decision-making process, with the aim of attaining a sustainable transport sector with lower costs and less impact on the environment.

THERMODYNAMIC CONSIDERATIONS FOR THE APPLICATION OF LIQUEFIED NATURAL GAS AS TRANSPORTATION FUEL

This study aims to analyze the thermodynamic considerations for the application of liquefied natural gas (LNG) as a transportation fuel. It is designed to solve transport fuel problems and tackle public health issues associated with vehicular engine emission, and vehicle fuel shortages. It considers the economic and technical viability of applying low-temperature fluid as fuel in an LNG-fuel Spark Ignition Engine through computer simulation. Process design configuration was achieved using the User Define Function (UDF) in fluid simulation software (ANSYS Fluent), Finite Element Analysis and Aspen Hysys. 12 kg capacity volume cryogenic tank design was done through Autodesk inventor with an initial temperature of -162 0C and pressure of 1 bar and ambient temperature application ranges of 20 0C to 40 0C. The ANSYS simulation result showed a thermodynamic effect of heat and mass transfer rate range of 1.6% to 7% W/m 2k concerning the time taken by the tank to absorb heat through temperature ranges of -155 0C to 250 0C. Also, 0.04kg/s was the total volume of boil-off gas (BOG) produced, while the maximum exhaust gas emissions recorded was 0.254kg/s. The advantage of this technology was the minimal volume of greenhouse gases released during combustion relative to gasoline and diesel, signifying less pollution, and buttressing the applicability and adoption of LNG-Fuel as a transport fuel.

Effect of hydrothermal temperature on the optical properties of hydrochar-derived dissolved organic matter and their interactions with copper (II)

Hydrothermal carbonization (HTC) has been regarded as a promising technique for turning wet biomass into hydrochar due to its low energy consumption, low exhaust gas emissions, etc. In addition, hydrochar is an important source of dissolved organic matter (DOM), which plays a crucial part in the migration and destiny of pollutants in the environmental medium. However, there are limited studies that focus on the factors that influence the formation of DOM in hydrochar, such as hydrothermal temperature. Therefore, the current study comprehensively characterized the optical properties of DOM within hydrochar derived from sawdust (HDOM) under different hydrothermal temperatures (150–300 °C) by Ultraviolet–visible (UV–Vis) and fluorescence spectroscopy, as well as its complexation characteristic with Cu(II). The findings revealed that the organic carbon content of HDOM reached a peak of 37.3 mg L−1 when the temperature rose to 240 °C and then decreased as the temperature increased. UV–Vis spectroscopy analysis showed that the absorption capacity of HDOM at 275 nm increases with temperature and reaches a maximum value at 240 °C, indicating that high temperature promotes the formation of monocyclic aromatic compounds. High temperature enhances the aromaticity, hydrophobicity, and humification degree of HDOM, thus improving its stability and aromaticity. The E3/E4 ratios are all greater than 3.5, confirming that the main component of HDOM is fulvic acid, which corresponds to 3D-EEM and Pearson's correlation coefficient analysis. The humification index (HIX) of HDOM increased with the rise in hydrothermal temperature (150–240 °C), as observed by the three-dimensional excitation-emission matrix spectroscopy (3D-EEMs). After reaching its peak at 240 °C, the HIX value gradually dropped in line with the trend of the DOC change. Moreover, the bioavailability (BIX) value of DOM was all high and greater than 1, indicating all the HDOM are readily bioavailable. Two microbial humic substances (C1 and C4), a humic-like substance (C2), and a protein-like substance (C3) were discovered in DOM by integrating 3D-EEMs with parallel factor analysis (PARAFAC). Their fluorescence intensity decreases as the Cu(II) concentration increases, indicating the formation of complexes with Cu(II). As the temperature rises, the binding ability of DOM and Cu(II) changes significantly, reaching the optimum at 300 °C. Meanwhile, the substance C2 has the strongest binding ability with Cu(II). This research emphasizes the significance of spectroscopy analysis in determining the evolution of hydrochar-derived DOM, the potential for heavy metal binding and migration, and its characteristics and features.Graphical

Investigating the impact of alumina nanoparticles in coconut oil distillate biodiesel to lessen emissions in direct injection diesel engine

Petroleum fuels are commonly used for automobiles. However, the continuous depletion and exhaust gas emission causes serious problems. So, there is a need for an alternative eco-friendly fuel. Biodiesel is a type of fuel manufactured through a process called transesterification, which involves converting vegetable oils into a usable form. The process parameters of the transesterification process were optimized using the Taguchi method to achieve maximum biodiesel yield. However, the main problem of biodiesel is its high cost which could be reduced by using low-cost feedstock. To address this challenge, biodiesel (BCFAD) is derived from coconut fatty acid distillate (CFAD), a by-product obtained from refining coconut oil. This work uses BCFAD and BCFAD with Alumina nanoparticles as fuels. Alumina nanoparticles in the mass fraction of 25 ppm, 50 ppm, and 100 ppm are dispersed in BCFAD. The investigation results reveal an increase of 6.5% in brake thermal efficiency for BCFAD with 100 ppm nanoparticles when compared to BCFAD. There is a reduction of 29.29% of hydrocarbon and 34% of Carbon monoxide emissions with BCFAD100 in comparison with diesel. However, there is a marginal increase in NOx emission with the increase in nanoparticles. The heat release rate and cylinder pressure of BCFAD100 are comparable to diesel fuel. It was concluded that the utilization of BCFAD with a nanoparticle dispersion of 100 ppm is suitable for direct use as fuel in diesel engines.

Development of Technology and a Convertеr for Neutralizing Greenhouse Gases Emitted from Automobiles

The article touches upon the issues of global warming associated with carbon dioxide (CO2) emissions into the atmosphere from vehicle internal combustion engines (ICE). To neutralize existing greenhouse gases emitted by ICE, in particular CO2, the interaction of the latter with various chemicals has been studied. The dynamics of exhaust gas emissions from ICE cylinders were observed. The experimental research was conducted to develop a greenhouse gas neutralization technology. Carbon dioxide neutralization converter with three neutralization batteries and a homogenization device is presented. This converter can guarantee CO2 neutralization of up to 92%. The formation of CO2 in the cylinders of modern petrol engines is due to the final combustion of the air-petrol fuel mixture. The combustion of the latter in the cylinder can be heterogeneous and diffusive. In addition, CO2 is generated in large quantities during diffusion combustion. The most effective method of diffusive combustion was chosen by the constructors of modern ICE, which is the formation of an artificial turbulent gas-dynamic condition for the fuel mixture due to the increase in the temperature of the air adsorbed in the cylinder, which ensures the engine's thermal energy efficiency coefficient of up to 35%. The CO2 volume in the exhaust gases of such engines reaches up to 16%. Thus, considering the perfection of modern ICE design for providing a high-efficiency reaction for the hydrocarbon oxidation in the fuel mixture in the combustion chamber, it becomes apparent that the presence of about 16% CO2 in the fractional composition of emitted dissolved gases is a serious problem in terms of increasing the volume of greenhouse gases in the atmosphere. Therefore, the goal of this article is to develop a reduction technology.

An Arsenic Removal Technology and Its Application in Arsenic-Containing Copper

The usage of copper (Cu) ores containing low or no arsenic (As) has reduced, and Cu ores containing high levels of As have emerged as vital mineral resources for Cu extraction and processing. The quality of the Cu ores has decreased from 1.6% to approximately 1.0%. The proportion of As to Cu in 15% of Cu resources currently reaches 1:5. However, during the extraction and processing of Cu ores, As presents significant environmental harm. Hence, safely and effectively removing As is paramount in Cu smelting and processing, holding substantial importance in fostering environmentally sustainable practices within the Cu extraction and processing industry. This article consolidates the resource distribution of As-containing Cu (ACC) ores, comprehensively and systematically evaluates the present advancements in extracting techniques for these minerals, and identifies the challenges inherent in pyrometallurgical and wet processes for treating ACC deposits. Pyrometallurgy is a simple primary roasting technique and has widespread applicability in the treatment of various ACC minerals. Its disadvantages are the emission of exhaust gas and the high treatment costs associated with it. The wet arsenic removal method boasts advantages including minimal air pollution and a high resource recovery rate, significantly aiding in Cu concentrate recovery; its major drawback is the production of As-containing wastewater. The hydrometallurgical removal of As from ACC mines involves extracting As through leaching. Recently, biometallurgy has presented innovative solutions using specialized microorganisms to bioleach or bioabsorb As, but large-scale industrial applications still lack specific practical implementation. This review explores the underlying causes of the challenges encountered in processing ACC minerals. Additionally, it highlights pyrometallurgical roasting coupled with high-temperature filtration as a pivotal advancement in the extraction and processing of ACC ores.

Aerobic composting characteristics of corn straw and pig manure under dynamic aeration

ABSTRACT The conventional aeration method is compulsorily continuous ventilation or aeration at equal intervals, and a uniform aeration rate does not vary during composting. A dynamic on-demand aeration approach based on the diverse oxygen consumption of microorganisms at different composting stages could solve the problems of insufficient oxygen supply or excessive aeration. This study aims to design an aerobic composting system with dynamic aeration, investigate the effects of dynamic aeration on the temperature rise and physicochemical characteristics during the aerobic composting of corn straw and pig manure, and optimise the control parameters of oxygen concentration. Higher temperatures and longer high-temperature durations were achieved under dynamic aeration, thereby accelerating the decomposition of organic compounds. Dynamic aeration effectively reduced the aeration frequency, the convective latent heat and moisture losses, and the power consumption in the middle and later stages of composting. The dynamic aeration regulated according to the oxygen concentration of 14%–17% in the exhaust was optimum. Under the optimal conditions, the period above 50 ℃ lasted 8.5 days, and the highest temperature, organic matter removal, and seed germination index reached 65.82 ℃, 37.59%, and 74.59%, respectively. The power consumption was decreased by 33.58% compared to the traditional intermittent aeration. Dynamic aeration would be a competitive approach for improving aerobic composting characteristics and reducing the power consumption and the hot exhaust gas emissions, especially in the cooling maturation stage, which was of great significance for realising the low-cost production of composting at scale and promoting the blossom of the organic fertiliser industry.

Combustion and emission characteristics of distilled waste plastic pyrolysis oil-gasoline blends using single cylinder motorcycle petrol engine

ABSTRACT This study assessed the performance and emissions characteristics of a single cylinder, 2-stroke motorcycle spark ignition engine (Esoo 150 cc) utilising clay-catalytically produced distilled waste plastic pyrolysis oil (DWPPO) fuel. The clay catalyst and fuel properties were analysed using established standard testing procedures. The engine performance and exhaust gas emissions were determined for various fuel blends and compared with those of commercial gasoline at various parameters. Results showed that distilled pyrolysis fuel properties (kinematic-viscosity: 6.4 × 10–7 m2/s; caloric-value: 47.82 MJ/kg) were enhanced compared to kinematic viscosity of 1.92 × 10–6 m2/s and caloric value of 44.41 MJ/kg for Crude Waste Plastic Pyrolysis Oil. Notably, chemical composition of distilled fuel collected within a temperature range of 90°C-180°C closely resembled those of pure gasoline. It was also shown that 50% Distilled Waste Plastic Pyrolysis Oil (D50WPPO) significantly improved the brake power, brake thermal efficiency and reduction in brake specific fuel consumption while operating at full load conditions with various DWPPO-Gasoline blends and pure gasoline. Unburned hydrocarbon emissions reduced by 40% when the engine was fuelled with D50WPPO. The study concluded that DWPPO can potentially be employed as a substitute of conventional gasoline without any engine modifications.

Experimental evaluation of the significance of scheduled turbocharger reconditioning on marine diesel engine efficiency and exhaust gas emissions

Poor clearances, misalignments, and carbon deposits in a turbocharger due to high running hours can decrease engine efficiency. This study analyzes the effects of turbocharger reconditioning on the performance and emissions formation of a marine diesel generator engine. The engine test experiments were performed on a university training ship's auxiliary diesel engine with 4309 running hours before and after the TC overhaul. As a result, cylinder peak pressure was increased by a maximum of 3.57 % while fuel saving of 5–8 g/kWh was realized. Lower exhaust gas temperatures and improved charge air pressure by up to 7.7 % were recorded. A significant CO emission reduction of 21.6 % was recorded at idle load whereas NOx and CO2 emissions were reduced to a maximum of 4.86 % and 7.30 % at 50 % engine load. The results indicate that scheduled TC overhaul and maintenance are very useful to improve the engine’s fuel economy, and performance and reduce exhaust emissions.

Effects of Blended Diesel-Biodiesel Fuel on Emissions of a Common Rail Direct Injection Diesel Engine with Different Exhaust Gas Recirculation Rates.

The aim of the study was to investigate the exhaust gas emissions and fuel consumption of a common rail direct injection (CRDI) diesel engine using mixed diesel (B10) and biodiesel (B20-B100) fuels. The study's primary objective was to determine the effects of blended diesel-biodiesel fuel on CRDI emissions based on different exhaust gas recirculation (EGR) rates, including carbon monoxide (CO), carbon dioxide (CO2), oxygen (O2), nitrogen oxide (NOx), and hydrocarbon (HC) emissions, smoke opacity, exhaust gas temperature, and fuel consumption. The CRDI experiments involved adjusting the different engine speeds (1400-3000 rpm) and EGR rates (0 and 12.5%), which were analyzed to determine their impact on these parameters for both blended diesel and biodiesel fuels. The results showed that under the conditions of no EGR (0%), the CO and HC emissions and the smoke opacity were lower than those with a 12.5% EGR rate for all fuel types and all cases. With 12.5% EGR rate, the O2 emissions and the EGT of the CRDI diesel engine decreased, which resulted in significantly lower NOx emissions because of EGR into the combustion chamber. For the maximum engine speed of 3000 rpm and with no EGR, the CO and HC emissions and the smoke opacity were lower than those with a 12.5% EGR rate for all fuel types. With a 12.5% EGR rate at 3000 rpm, the O2 emissions and the exhaust gas temperature were reduced by 0.07% and 2.27%, respectively, and the NOx emissions were reduced by 2.54%. However, with EGR, the CO and HC emissions and the smoke opacity increased by 7.70%, 18.61%, and 0.4%, respectively. Furthermore, the fuel consumption of pure biodiesel (B100) at 3000 rpm with a 12.5% EGR rate was reduced by 2.81% compared to that with a 0% EGR rate. Because the temperature in the combustion chamber is high enough for the engine to run, the EGR reuses a portion of the exhaust gases and can help to minimize the quantity of fuel in the combustion chamber. As a suggestion based on these observations, biodiesel fuel should not exceed B80 because the viscosity and density of fuel that are too high may affect the fuel injection system, both the injectors, and the pressure pump, causing the injectors to be unable to work correctly. These findings can contribute to the development of strategies and technologies for reducing emissions and improving fuel efficiency in CRDI diesel engines.

Analysis of the impact of exhaust gas emissions on diesel fueled vehicles in view from the year of manufacture (Case study on the Mitsubishi L 300 vehicle)

Air pollution is a condition caused by exhaust gas from motor vehicles operating on the highway. To minimize greater air pollution, the government is making preventive efforts by carrying out regular vehicle emission tests which are currently being carried out targeting transport vehicles. This is triggered by the increasing development of the automotive industry so that every year manufacturers produce these vehicles to meet the vehicle market, especially transport vehicle. With the increase in the number of vehicles every year, this is one of the causes of air pollution, so it needs to be controlled. This research aims to determine the effect of vehicle exhaust emissions on the year of vehicle production, in diesel fueled vehicles. The method used is an experiment using two-way Anova analysis on the results of tests carried out on Mitsubhisi L 300 vehicles with a total of 30 test samples, by testing vehicles produced in 2017 - 2022. The results of the research show that older vehicles will produce gas emissions. tall one. This is in accordance with the results of the ANOVA test which accepts the statement that there is at least one vehicle age that has a significant effect on smoke concentration, so it can be concluded that vehicles with an old age, in this case 2017, have the potential to produce high emission gases, therefore preventive efforts need to be taken. to vehicle engines

Performance of Transition Metal Supported Al2O3 Coated on Honeycomb Catalysts and Its Segmentation on Exhaust Gasses Oxidation

The oxidation of carbon monoxide (CO) and unburnt hydrocarbons (HC) under segmented honeycomb catalysts was investigated using actual exhaust gas mixtures from a gasoline-fueled internal combustion engine of a motorcycle. The honeycomb catalysts were prepared through a wet process, resulting in four types coated with transition metals (Cu, Cr, Fe, and Ni) supported on Al2O3. The oxidation of CO and HC was monitored using an exhaust gas analyzer across a range of air-to-fuel ratios (AFR), from lean to rich, under stationary conditions. The results demonstrate that the honeycomb catalysts effectively decreased CO and HC concentrations in the exhaust gas. Among the transition metal oxide honeycomb catalysts, Cr and Ni exhibited high CO and HC conversion rates, surpassing those observed with Cu. The average CO and HC conversion calculations, spanning from lean to rich air-to-fuel ratios, were consistent with the actual conversion rates achieved. Furthermore, the study investigated the effect of honeycomb segmentation on CO and HC conversion. Surprisingly, the catalytic performance of Cr and Ni remained high even with longer gaps in the honeycomb. Interestingly, the conversion of CO and HC over the iron oxide honeycomb catalyst increased as the gap in the honeycomb became longer. This is likely due to an increase in the gap size and enhanced re-mixing of reactants (CO, HC, and O2) caused by recirculation. Thus, this study provides valuable elucidation on the potential application of segmented honeycomb catalysts for reducing CO and HC emissions in exhaust gases.

Investigation on the combustion of ammonia using direct high/medium-pressure-Otto injection approach in a diesel two-stroke marine slow speed engine

The urgent need to reduce exhaust gas emissions has led to increased research activities on the potential of using ammonia as fuel in marine engines. Various researchers have already investigated the combustion of ammonia specifically in two-stroke, slow-speed marine engines, and obtained promising results. In the available literature, both high-pressure direct injection-Diesel (HPDF) and low-pressure direct injection dual fuel - Otto (LPDF) two-stroke engines have been well-researched. This study numerically investigates the potential of using a direct high/medium pressure (Otto) ammonia injection strategy on a marine two-stroke engine. A diesel-fueled engine was retrofitted with ammonia injectors on the cylinder head. The effects of ammonia injection direction, timing, and injection pressure on the combustion efficiency, engine performance, and exhaust gas emissions were investigated to ensure optimum injection parameters. Ammonia substitution rate (ASR) ranging from 40 to 80 % was used in this study. The investigated injection strategy revealed flexibility in achieving the original pure diesel engine power over a wide range of injection pressures (700-200 bar). At 80 %, ASR CO2 emissions were reduced up to 80 % while NOx emissions attained Tier II emission limits. The results of this study are helpful in the development process of ammonia dual-fuel marine two-stroke engines.

Recent advances in electrostatic precipitation of particles from flue gases generated by domestic heating appliances. A brief outlook

Winter season is the time of increased emission of exhaust gases from household heating appliances containing particulate matter (PM) and other noxious contaminants. Many old buildings and single houses, particularly at rural and small town regions, still use stoves, fireplaces or ovens to flat heating. Besides qualified fuels like coal or biomass pellets, all kinds of wastes are also burned in many cases, producing not only mineral particles but also toxic volatile organic compounds or other carcinogenic species. To solve the problem of high level of emission of solid particles and organic-compound molecules different constructions of electrostatic precipitators, which can remove such particles, have been developed in last two decades, which were designed to operate downstream of small domestic boilers. Such electrostatic precipitator must comply with the ECODESIGN emission limits, which set the emission level at 20 mg/m3, for biomass. The mass collection efficiency should be higher than 95 % to obtain this emission level. This brief review presents different constructions of electrostatic precipitators designed to be used for the removal of fly ash particles from domestic heating appliances.

Optimization and impact of modified operating parameters of a diesel engine emissions characteristic utilizing waste fat biodiesel/di-tert-butyl peroxide blend

This study comprehensively investigated the transesterification process of converting waste pork fat oil into biodiesel as a fuel for the common rail direct injection (CRDI) diesel engine. In addition, Di-tert-butyl peroxide (DTBP) is used as an ignition enhancer to minimize exhaust gas emissions. The test fuels are diesel and diesel-waste pork fat biodiesel (WPFB)-DTBP blend (B20DTBP10 by volume), were used to analyze the engine outcome parameters with modified engines operating conditions like various compression ratios (CRs 16, 17.5, and 19) and injection pressures (IPs 400, 500 and 600 bar) at maximum load. The experiment results revealed that higher CRs and IPs, the heat release rate (HRR) and cylinder pressure increased. The brake thermal efficiency (BTE) is enhanced by increasing CRs and IPs but lowered than neat diesel. Smoke opacity decreased while increasing CRs and IPs. At CR 19 and IP 600 bar, smoke opacity decreased by 18.29%, related to baseline diesel. Increasing CRs and IPs lowered HC and CO emissions, but increasing IPs increased both emissions. HC and CO emissions were lowered in CR 19 and IP 500 bar by 21.73% and 28.49% more than neat diesel. The lower CRs and IPs, the oxides of nitrogen (NOx) emissions decreased, but further increasing CRs and IPs, the NOx emissions increased. Compared to baseline diesel, NOx emissions decreased in CR 16 and IP 400 bar by 15.49%. It was discovered that with increasing CRs and IPs, the emissions decreased with a minor rise in NOx emissions. Furthermore, the experimental results matched the predictions of an artificial neural network (ANN) model. The research concluded that the blend B20DTBP10 with modified engine operating conditions CRs and IPs suits diesel engine operation.

Comprehensive assessment of environmental impacts: exhaust gas emissions from goods transport trucks in Manokwari regency and effective mitigation strategies

This study aimed to analyze the concentration of %HSU (Heavy Smoke Unit) in the exhaust emissions of freight trucks in Manokwari Regency. It employed a quantitative research approach and utilized incidental sampling to select a total of 30 vehicles as samples. To examine the relationship between exhaust emissions and vehicle characteristics, linear regression analysis was employed. Out of the 14 vehicles (46.67%) that failed the emission test, only 2 (14.29%) were produced before 2010, while the production of the remaining 12 (85.76%) was after 2010. Simultaneously, Cylinder Capacity (X₁), Trip Length (X₂), Vehicle Age (X₃), and Vehicle Maintenance (X₄) influenced the %HSU value (Y). This was indicated by the very small p-value (0.000), where the mean differences between the groups were highly statistically significant. The results showed that the independent variables were mutually related and collectively have a significant impact on the %HSU value.