Exhaust Gas Emissions Research Articles

Reducing particulate emissions by using advanced engine oil nanoadditives based on molybdenum disulfide and carbon nanotubes

Nanoadditives can be used to enhance lubricating properties of engine oils. Although many additives have been developed, molybdenum disulfide and carbon nanotubes have attracted significant attention. In this study, we demonstrate that hybrid nanostructures based on these unique materials (MoS2/CNTs) positively affect engine oil lubricating properties. Hybrid nanostructures were produced via wet chemical synthesis in impinging jet reactor. This method is characterized by easy scalability and possible continuous operation, which are crucial in material commercialization. The application of 0.5 wt% suspension exhibited the best results, reducing the friction coefficient at the engine operating temperature by up to 26%. Nanoadditives protected the lubricated parts, causing their wear to be considerably lower than the base oil. The effect of nanoadditives on the quality of exhaust gases was also investigated, which has not yet been researched. The application of the oil with MoS2/CNT reduced the emissions of solid particles in the gasoline engine exhaust gas. The total volume of particles in the exhaust gas was reduced by 91% and 49% under idling and load-running conditions. This research showed that MoS2/CNTs can be successfully used as nanoadditives in engine oils for improving tribological properties, enhancing anti-wear performance, and reducing particle emissions in exhaust gas.

Experimental investigation of the effect of fuel oil, graphene and HHO gas addition to diesel fuel on engine performance and exhaust emissions in a diesel engine

Today, research for alternative fuels continues due to the increasing energy demand, exhaust emission restrictions, and depletion of fossil fuels. It is important to use diesel engines for the opening of new oil fields in Turkey and for the utilization of fuel oil to be produced in these oil fields. In this study, pure diesel (D) diesel 60% and fuel oil 40% (DF40) were supplied by volume with an ultrasonic mixer. 50 (DF4050 N) and 100 ppm (DF40100 N) graphene have been added to eliminate fuel oil's adverse combustion effects by keeping the fuel oil constant. In addition, HHO gas was added to improve the combustion even more with a flow rate of 5 (DF4050N5H and DF40100N5H) and 10 (DF4050N10H and DF40100N10H) lt/min into the intake manifold by using the HHO generator. Experiments were carried out at 3000 RPM constant speed at 3.2, 6.4, 7.9, and 12.8 Nm engine torque without any modification on the diesel engine. The effects of these mixtures on combustion performance and exhaust emissions were investigated. Exhaust gas temperature and emissions were measured in the experiments. According to the measurements, thermal efficiency, brake specific energy consumption (BSEC), HC, CO, CO2, particle emission, and NOx emission values are given. Brake specific energy consumption (BSEC), CO, HC, and particle emissions decreased, and thermal efficiency, NOx, CO2, and exhaust gas temperature increased with the engine torque value increased as a result of the experiments. Thermal efficiency and CO2 emission decreased, and BSEC, exhaust gas temperature, HC, CO, NOx, and particulate emissions increased by adding fuel oil to diesel fuel. The thermal efficiency was increased by adding graphene and HHO gas from the intake manifold to DF40 fuel. The thermal efficiency improved, and emissions decreased with the more addition of graphene and HHO gas. Adding HHO gas improved thermal efficiency significantly at the 12.8 Nm engine load. With the addition of graphene and HHO gas to DF40 fuel, the BSEC value was improved at high torque values. The effect of improving thermal efficiency is also understood from the decrease in CO emissions and the increase in CO2 emissions. HC and PM emissions decreased with the addition of graphene and HHO gas. It was observed that NOx and exhaust gas temperature increased with increasing thermal efficiency.

Analysis of Energy Flow in a Mid-Sized Electric Passenger Vehicle in Urban Driving Conditions

Because of emissions of exhaust gases, global warming is proceeding, and air pollution has increased. Thus, many countries are manufacturing eco-friendly vehicles, including electric vehicles. However, the range of electric vehicles is less than the range of internal combustion engine vehicles, so electric vehicle production is being disrupted. Thus, it is necessary to analyze the energy flow of electric vehicles. Therefore, to analyze energy flow of electric vehicles, this study suggested an energy flow structure first, then modeled the energy flow of the vehicle, dividing it into battery, inverter and motor, reduction gear and differential, and wheel parts. This study selected a test vehicle, drove in urban driving conditions and measured data. Then, this study calculated energy flow using MATLAB/SIMULINK in real time, and calculated and analyzed energy loss of each of the vehicle’s parts using the calculated data.

Influence of thermal barrier coating on performance and emission characteristics of a compression ignition engine fueled with delonix regia seed biodiesel

The selection of Delonix regia seed biodiesel as a prominent renewable source is attributed to its ability to effectively replace conventional fuel. While the use of Delonix regia seed biodiesel does reduce the emission of harmful exhaust gases, the engine efficiency is not equivalent to that of conventional diesel fuel. The piston and cylinder liners underwent a plasma spray process in which they were coated with equal amounts of a blend of Al2O3 and YSZ. The piston and cylinder-liner were coated with a thermal barrier coating at thicknesses measuring 100 and 200 μm, respectively. The current research focuses on the utilisation of an 80% blend of Delonix Regia biodiesel in a compression ignition (CI) engine, which presents a novel approach in the field. The investigation of Delonix Regia biodiesel as a fuel for CI engines has been the focus of limited scholarly inquiry, with studies primarily restricted to blends containing a maximum of 30% biodiesel. This limitation is primarily attributed to the biodiesel's higher viscosity and lower calorific value. These identified attributes have been observed to have a negative impact on the functioning of the engine, leading to less than optimal results. Therefore, a study was undertaken to evaluate the efficacy of Delonix regia seed biodiesel in a thermal barrier coated CI engine, resulting in favourable engine performance and reduction of pollutants. The results of the comprehensive test indicated that the mean specific fuel consumption decreased by 0.0425kg/kWh and 0.015kg/kWh, while the brake thermal efficiency improved by 3.1% and 1.2% when comparing the usage of an 80% biodiesel blend and diesel fuel in an unmodified compression ignition engine. The levels of carbon monoxide, an environmentally harmful pollutant gas, were observed to decrease by 0.059% in terms of volume. Similarly, the emission of unburned hydrocarbons exhibited a reduction of 28 ppm. Additionally, the smoke opacity was found to decrease by 6.52%. The observed NOx level exhibited an increase of 270 ppm in comparison to that of diesel fuel.

Enhancing the thermal stability and activity of Pd–Rh/Al2O3 catalyst for three–way catalytic reaction by introducing Pt and varying the synthesis method

Three–way catalysts (TWCs) are used to remove exhaust gas emissions from the gasoline vehicle engine. The vehicle engine temperature rises to 1000 °C which is harsh condition; therefore, maintaining catalytic activity is so difficult by metal sintering. In this study, the effects of introducing Pt and the synthesis method of Pd–Pt–Rh/Al2O3 catalysts were investigated for enhancing the thermal stability and three–way catalyst activity. Therefore, three synthesis methods were introduced: co-impregnation, sequential impregnation, and physical mixing. The thermal aging was conducted at a high temperature (950 °C), wherein a 1 h lean–rich cycle was repeated 30 times. The physically mixed catalyst exhibited higher thermal stability than other catalysts. Pt was impregnated first, and Pd and Rh were physically separated in physically mixed catalysts; therefore, sintering was inhibited after thermal aging. The aged physically mixed catalyst presented the highest PdO and PtOx ratio, resulting in high oxidation activity. To further enhance the catalytic activity after thermal aging, the Pd/Pt ratios were varied with a constant Rh content. When the Pt content was increased in physically mixed catalysts, the catalytic activity of the aged catalysts increased. Therefore, the physically mixed catalyst with a high Pt ratio was suggested as the optimal catalyst which exhibited high sintering inhibition.

Development of Low Emission Combustion Technologies For Modern Aero Gas Turbine Engines: An Overview

The demand for gas turbines for civil aviation is increasing continuously as the air transportation system is changing exponentially. Large fleet of commercial aircraft and large and long-haul flight have raised the demand on high thrust engines. Therefore, focus on fuel efficiency of the engines and control on exhaust gas emissions are increasing keeping in mind the economy and environmental considerations. International Civil Aviation Organization has promulgated the emission levels for civil subsonic turbojet and turbofan engines and making it more and more stringent day by day. This paper overviews various combustor technologies which have been developed over previous decades and are under development currently for present and future aircraft to meet the low emission goals.

The Trend of Bypass Ratio in Aero Engines: An Overview

The demand for turbofan engines for civil aviation is increasing continuously as the air transportation system is changing exponentially. Large and long-haul flight have raised the demand on high thrust engines. But at the same time, focus on fuel efficiency of the engines and control on exhaust gas emissions and noise are increasing keeping in mind the economy and environmental considerations. International Civil Aviation Organization has promulgated the emission and noise levels for civil turbofan engines and making it more and more stringent day by day. This has made an increasing trend of engine bypass ratio to address the fuel efficiency and the noise level of the engine. On the other hand, combat aircraft need to have high ‘g’ manoeuvrability, a faster response to throttle adjustment and high thrust-weight ratio thus preferring a low-bypass ratio world-wide. This paper covers the history of turbofan engines staring from its inception and presents the trend of bypass ratio in aero engines for both transport and combat aircraft. The paper also highlights the current developments and upcoming ultra-high bypass turbofan engine programs along with aircraft noise standards.

Evaluation of Performance Improvement of Gasoline Fuels by Adding Propanol, Ethanol, and Diisopropyl Ether along with Metal Oxides of CeO2 and Fe2O3

Many studies focusing on the composition of gasoline with any type of fuel additives have shown that the overall engine performance has a significant impact on reducing emissions. In this research work, ethanol, isopropanol, and diisopropyl ether as oxygenated additive with cerium oxide (CeO2) and iron(III) oxide (Fe2O3) as metal nanoparticles were combined with pure gasoline. Due to the more oxygen they have in their structure, these alcohol additives reduce pollutants and complete combustion. Metal nanoparticles also improve the performance of the engine due to the proper potential. To check the efficiency of the new fuel, a four-stroke engine connected to a dynamometer and an analyzer tested different conditions: speed of 1500 and 2000 rpm and loading percentage of 30 and 40%. Analyzed data include the engine power, and the amount of CO, CO2, HC, and NOx released. The power of the engine on gasoline fuel was 14.43 at 1500 rpm, and once the test was repeated with mixed fuel with additives, it increased to 17.5, which indicates an improvement in engine performance. The amount of CO emissions at 1500 rpm with gasoline fuel was 3.25, and once repeating the test with the same engine rpm with mixed fuel, it decreased to 1.68. The amount of CO2 at 1500 rpm with gasoline fuel was 3.8 and repeating the test with mixed gasoline, it was 5.7. The amount of HC emission with gasoline was 65, and it was 62 when tested with mixed fuel. The amount of NOx released in comparison of gasoline fuel with mixed fuel reached from 264 to 533. The performance improvement and pollutant emissions are fully described in the conclusion section. The analyzed data were calculated and transformed into a model. Among the additives used, isopropanol and CeO2 nanoparticles had better results in optimizing the fuel, reducing the pollutants, and increasing the engine performance. The optimization results show that the use of isopropanol (5%) and CeO2 (1.39 wt. %) as well as diisopropyl ether (4 wt. %) at high engine speed (1504.97 rpm) can be improved engine performance and reduce exhaust gas emissions.

Sustainable production of bio‐fuel derived from vegetable waste via pyrolysis technique

AbstractThe impact of growth in the overall population is imposed on the continuous degradation process for environmental wastes like agricultural, industrial, food products, farming waste, etc. The improper degradation may lead to pollution and toxicity for ecological living. Based on waste management concepts, environmental wastes are reduced, reused, and recycled against environmental pollution. Most environmental wastes are recycled and used as biofuel for various energy sectors like alternative fuels. Globally, vegetable loss or wastage increased by more than 35% due to the level of retailers and consumers. The present study attempts to produce a low‐cost, reliable, environmentally emission‐free biofuel using waste vegetable resources via pyrolysis reactor arrangements. The synthesized bio‐fuel energy implemented for compression ignition engine and its performance was evaluated by single cylinder four stroke diesel engine and found higher brake power and thermal efficiency of 6.89 kW and 50.29%. Finally, the emission characteristics are assessed by an exhaust gas emission tester. CO and HC emissions showed minimum amounts like 0.021% and 47 ppm.

Evaluation of Ca-Based Sorbents for Gaseous HCl Emissions Adsorption

The problem of acid gas exhaust emissions treatment has not been fully resolved at present. Dry adsorption of acid gases with alkaline sorbents is currently being investigated, to improve solid sorbents. In this study, 5 types of hydrated lime were characterised and tested. The sorption capacities were measured by means of a system consisting of a feed line (HCl/N2), a thermostatic reactor and a water absorber. The physical characteristics of sorbent samples were also compared. Analyses conducted with scanning electronic microscopy revealed that sample C1 showed uniform particle distribution. Samples C2 and C3 showed the co-presence of fine and coarse particles. Sample C4 showed very fine particles with agglomeration phenomena. In sample C5, fibrous elements were found. Energy dispersive spectrometry (EDS) analyses showed a similar composition of the samples, with the exception of the presence of Mg in some of them. After 30 min of testing, the following differences in sorption capacities with respect to C1 (3.59 mg g−1) were found: C2, −20%; C3, −13%; C4, −17%; C5, −3%. Higher sorption capacities were associated with more uniform particle size distributions. Conversely, agglomeration of fine particles may have adversely affected the performance of sorbents.

Self-powered exhaust gas purification by negative ions and photoelectric catalysis based on triboelectric nanogenerator

Industrial exhaust gas emissions have caused many environmental problems such as particulate matter (PM) pollution and volatile organic compounds (VOCs) emissions, seriously endangering human’s health. Here, we demonstrate a new method for air purification and degradation of VOCs based on synergetic effects of electric-assisted photocatalysis and negative air ions generated by direct-current triboelectric nanogenerators (DC-TENG). The negative electrode of DC-TENG is connected to carbon fiber bundle (CFB) to generate negative air ions, while the positive electrode of DC-TENG is connected to dust collection board loaded with catalyst and can provide a bias electric field for photocatalysis, allowing VOCs to be adsorbed onto the collection board and accelerating the efficiency of photocatalytic degradation. Under the driving of DC-TENG, 1.1 × 1013 negative ions are generated by CFB per second, which can reduce PM2.5 concentration in a sealed box from 999 μg·m−3 to less than 50 μg·m−3 within 80 s. The proposed system combining negative ions and photoelectric catalysis can reduce formaldehyde concentration from 1.97 ppm to 0 ppm in 12 min, which is 2.4 times higher than the degradation rate of photocatalysis alone. This air purification system demonstrated here not only harvests the wasted environmental energies but also proposes a new strategy to sink particulate matter and degrade VOCs in the air, demonstrating a cleaner, more efficient, multifunctional, and self-powered exhaust gas treatment system that can provide new solutions for future air purification.

Exergy Analysis of Supercritical CO2 System for Marine Diesel Engine Waste Heat Recovery Application

In this research is performed an exergy analysis of supercritical CO2 system which uses various waste heat flows from marine diesel engine to produce additional mechanical power. The performed exergy analysis contains whole system as well as each system component individually. The observed system produces useful mechanical power equal to 2299.47 kW which is transferred to the main propulsion propeller shaft. Additionally produced mechanical power by using waste heat only will reduce marine diesel engine fuel consumption and exhaust gas emissions. Main cooler has the highest exergy destruction of all system components and simultaneously the lowest exergy efficiency in the observed system, equal to 32.10% only. One of the possibilities how main cooler exergy efficiency can be increased is by decreasing water mass flow rate through the main cooler and simultaneously by increasing water temperature at the main cooler outlet. Observed system has five heat exchangers which are involved in the CO2 heating process, and it is interesting that the last CO2 heater (exhaust gas waste heat exchanger) increases the CO2 temperature more than all previous four heat exchangers. Whole analyzed waste heat recovery supercritical CO2 system has exergy destruction equal to 2161.68 kW and exergy efficiency of 51.54%. In comparison to a similar CO2 system which uses waste heat from marine gas turbine, system analyzed in this paper has approximately 12% lower exergy efficiency due to much lower waste heat temperature levels (from marine diesel engine) in comparison to temperature levels which occur at the marine gas turbine exhaust.

Tribological performance of nanopowder blended bio-diesel

Biodiesel is renewable, sustainable, and an alternative fuel for compression ignition engines, and often recognized as a comparable fuel to diesel in diesel engines. This is due to a variety of factors, including less dependency on imported petroleum, less global warming, and lower diesel engine exhaust gas emissions. Cottonseed oil is converted into biodiesel by the well-known transesterification method. The ultrasonication approach is used to evaluate the bio - diesel B20 (0.8 %diesel + 0.2 %biodiesel) as well as B50 (0.5 % diesel + 0.5 %biodiesel) with Aluminum oxide nanoparticles in concentration of 50 and 100 ppm. The tribological properties of these blended samples are investigated at varied speeds and loads considering AISI 1040 steel disc with aluminium pins. The addition of Al2O3Nanoparticles helps in further enhancing the tribological properties of the biodiesel made of cotton seed oil. The results reveal that a properly concentrated Al2O3 nanofluid has strong tribological characteristics and has the capability to substitute conventional lubrication. The nanofluid has higher tribological qualities over pure cottonseed oil as well as boosts its performance substantially.

Experimental Investigation of Exhaust Gas Emission Status in Tanzania: A Case Study of National Institute of Transport Vehicle Inspection Center – Dar es Salaam

Exhaust gas emission is a by-product of air and fuel combustion in vehicle engines. It is a crucial contributing factor to air and environmental pollution that authorities emphasize controlling to mitigate the health and environmental hazards to communities. This was an experimental investigation to ascertain the emission status of used vehicles used for transport in Tanzania, some on the verge of surpassing their allowable emission levels. An experimental research design was opted for in this study and data were collected experimentally and through observations. Gas analyzers and emission detectors were used to obtain emission data for the study, where cluster sampling was preferred and 403 gasoline and diesel-powered vehicles were investigated for general inspection. The study found that engine size, year of manufacture, and kilometers of travel affected vehicle emission levels. The results were analyzed and compared with the allowable emission values in the Tanzanian standards.

PENGARUH KOMPOSISI KATALIS Cu-Fe/AL2O3 DAN PANJANG HOUSING CATALYTIC CONVERTER TERHADAP EMISI GAS BUANG MESIN 4 LANGKAH 125 CC

Catalytic Converter is a device that is used to control exhaust gas emissions in the muffler. In the Catalytic Converter there is a media that is a catalyst, where the media is expected to help or accelerate the process of changing a substance (chemical reaction). Generally, the catalysts used today still use noble active metals, such as Platinum (Pt), Palladium (Pd), and Rhodium (Rh), which are low in availability and relatively expensive. Instead, other alternative materials are used, namely active transition metals such as Copper (Cu), Chromium (Cr), Nickel (Ni), and Iron (Fe) which are easy to find and have a lower price.The purpose of this study was to determine the effect of the Cu-Fe/Al2O3 composition on the catalytic converter catalyst on the exhaust emissions of a 125cc 4 stroke engine. The research method used is the experimental method by mixing the composition of 10% Cu, 0% Fe, 90% Al2O3; 2.5% Cu, 2.5% Fe, 90% Al2O3; 5% Cu, 5% Fe, 90% Al2O3; 2.5% Cu, 7.5% Fe, 90% Al2O3; 0% Cu, 10% Fe, 90% Al2O3; on the catalyst and housing length variations with sizes of 30 mm, 60 mm.The results of this study indicate that a catalyst with a housing length of 30 mm with a composition of 2.5 Cu – Fe 7.5% can reduce CO gas up to 0.8%. With an average of 1.82% compared to the standard exhaust which has an average of 4.86%, resulting in a decrease in CO gas of 3.06%. Also, there was a decrease in HC gas in the catalyst composition of 0% Cu – 10% Fe which was able to reduce HC gas up to 51 ppm. With an average of 53 ppm compared to the standard exhaust which has an average of 152 ppm, there is a decrease in HC gas of 99 ppm.

Combustion and emissions characteristics of a diesel engine fuelled with diesel fuel and different concentrations of amino-functionalized multi-walled carbon nanotube

Nanoparticles have recently been used as fuel additives to enhance diesel engine performance and exhaust gas emissions. Amino-functionalized multiwalled carbon nannotubes (NH2-MWCNTs) are catalysts that can be applied in diesel engines because of their promising properties. This study conducted an experimental investigation to determine the impacts of adding NH2-MWCNTs to diesel fuel using a single-cylinder CI engine running at a constant speed (1500 rpm) and various loads. The NH2-MWCNTs were added to diesel fuel at four concentrations of 25, 50, 75, and 100 ppm. Also, the same doses of pristine multiwalled carbon nanotubes (MWCNTs) were added to diesel to be used as a reference for NH2-MWCNTs. Most NH2-MWCNTs blends were preferred in combustion characteristics, engine performance, and exhaust emissions compared to diesel and MWCNTs blends. Thus, there was a considerable increase in cylinder pressure and heat release rate compared to pure diesel. Also, the brake thermal efficiency was increased, and the brake-specific fuel consumption was decreased compared to diesel. Most NH2-MWCNTs combinations appeared to decrease NOx, soot, and CO levels significantly. The NH2-MWCNTs blends are generally favored over the pristine MWCNTs blends in reducing exhaust emissions.

Simulations of ammonia spray evaporation, cooling, mixture formation and combustion in a direct injection compression ignition engine

This study investigates the novel approach of direct liquid ammonia injection into the combustion chamber of a compression ignition engine. Unlike traditional gaseous ammonia port injection, this method shows promise in reducing ammonia slip and emissions. To simulate and analyze the behavior of the liquid ammonia spray, we employed numerical models based on existing literature on flashing and non-flashing spray simulations, as well as recent experimental studies on ammonia spray characteristics using a gasoline direct injection (GDI) injector. Our approach utilized a Lagrangian discrete phase modelling technique to perform a series of three-dimensional computational fluid dynamics (CFD) simulations. The primary objectives of this research were to evaluate the evaporation process of ammonia and its cooling effect, as well as to gain insights into mixture formation within the engine cylinder under different operating conditions. The simulations encompassed the entire engine cycle, considering a multi-hole GDI ammonia spray in conjunction with pilot n-heptane, a diesel surrogate, in equal proportions on an energy basis. Three distinct injection timings for ammonia were examined, leading to varying thermodynamic conditions within the combustion chamber during each spray formation. Consequently, different modelling parameters and initial conditions were necessary to accurately replicate the spray behavior. To address this, we proposed a systematic procedure for assigning pre-defined spray angles. The non-reacting, evaporating spray simulations yielded valuable insights into the mixture formation process, which guided our analysis. Finally, reacting conditions were considered to evaluate engine performance and resulting exhaust gas emissions. This study provides a comprehensive overview of critical aspects related to direct ammonia injection in internal combustion engine (ICE) systems. Moreover, it uncovers performance trends that can serve as a foundation for future investigations in this field.

Energy and exergy analysis of VCR engine fueled with rubber-seed oil methyl ester using response surface methodology

This study presents a comprehensive analysis of the thermodynamic performance of a variable compression ratio engine fueled with rubber-seed oil methyl ester blended with diesel. The objective is to evaluate the energy and exergy characteristics according to the first and second laws of thermodynamics for various compression ratios and supercharging pressures. A 3.5 kW engine with compression ratios values ranging from 18:1 to 22:1 and SC pressures of 0, 0.25, and 0.5 bar (g) at 80% load was considered. The inlet manifold pressure was controlled using a centrifugal-type blower (1.5 m3/min, 350 W, 240 V AC) with an adjustable valve. Key fuel energy parameters including shaft energy, cylinder pressure, brake specific energy consumption, thermal efficiency, heat release rate, absorbed energy by cooling water, exhaust gas temperature, exergy efficiency, exergy destruction, exhaust energy, and emissions were analyzed. Results showed significant improvements in shaft energy (35.51%), thermal efficiency (35.37%), and heat release rate (25.17 J/°CA) for compression ratios 20 and supercharging pressure of 0.25 bar, with a reduction in brake specific energy consumption of 2.912 kJ/s kW. The second law efficiency and irreversibility were observed to be 60.31% and 0.0118 kW/K, respectively. Experimental findings demonstrated a reduction in carbon monoxide (25.12%) and hydrocarbon (40%) under the aforementioned conditions. Response surface methodology was employed to predict optimal operating conditions, and the equations were validated using analysis of variance and p-test. The D-optimality test facilitated the determination of optimal operating parameters for different responses through multi-objective optimization techniques. Individual desirability values were combined to obtain a composite desirability of 0.9054. The study identified compression ratios 18 with a supercharging pressure of 1.78 bar as the optimum operating condition for 20% fuel blends in a low-speed agricultural diesel engine, resulting in a remarkable improvement of 41.24% in energy efficiency and 68.45% in exergy efficiency, with minimal emissions.

Studies of Engine Performance and Emissions at Full-Load Mode Using HVO, Diesel Fuel, and HVO5

The aim of the study was to determine impact of commercially available hydrotreated vegetable oil (HVO) and its mixture (HVO5, where 5% (v/v) HVO and 95% (v/v) FDD) with diesel fuel (FDD) on the power, torque, fuel consumption, and exhaust gas composition of an atmospheric internal combustion diesel engine used in off-road applications. Diesel fuel was used as the comparative fuel. Testing was realized in a full-load mode on the KOHLER KDI 1903 M 3-cylinder diesel engine on a SIERRA CP-Engineering engine test bench. The AVL SESAM FTIR exhaust gas analytical system was used to determine exhaust gas emissions, while the AVL KMA Mobile fuel consumption measuring device was used to measure fuel consumption. Research showed that the lowest power and torque readings were obtained with FDD, while HVO showed a slightly higher result compared to the fossil diesel fuel. At the same time, the highest hourly fuel consumption was observed running on HVO5, while the lowest was observed with FDD. Increases in carbon monoxide (CO), carbon dioxide (CO2), and nitrogen oxide (NOx) emissions were observed for HVO5 compared to those of FDD. The CO content in emissions increased by an average of 3.0% using HVO and by an average of 36% using HVO5, but the NOx content in the emissions increased by an average of 3.0% using HVO and by an average of 8.8% using HVO5. The reduction by an average of 60% using HVO in emissions was found in the case of hydrocarbons (HC). Research confirmed that the physicochemical properties of HVO could leave an impact on the main engine performance parameters and exhaust emissions.

Environmental risk assessment near a typical spent lead-acid battery recycling factory in China

In recent years, environmental pollution and public health incidents caused by the recycling of spent lead-acid batteries (LABs) has becoming more frequent, posing potential risk to both the ecological environment and human health. Accurately assessing the environmental risk associated with the recycling of spent LABs is a prerequisite for achieving pollution control. In this study, a spent LABs recycling factory in Chongqing was investigated through on-site investigation, sample analysis. Exposure assessment and health risk assessment were also conducted. The results showed that: firstly, Pb and As concentrations exceeding the standard limit values were found in the environmental air and vegetables near the spent LABs recycling factory. Secondly, exposure assessment results showed that total average daily exposure to hazardous substances for children (3.46 × 10−2 mg/kg) is higher than for adults (4.80 × 10−2 mg/kg). The main exposure pathways for Pb, Cr, Ni, Cu, Zn, and Hg are ingestion of vegetables, while those for Cd, As, and Sb are through inhalation. Thirdly, health risk assessment results indicate that environmental exposure poses unacceptable non-carcinogenic and carcinogenic risk to both adults and children near the spent LABs recycling factory, with children facing higher risk than adults. Pb and As are the main contributors to non-carcinogenic risk, and Ni and As are the main contributors to unacceptable carcinogenic risk. In particular, As, has a greater contribution to total carcinogenic risk index through inhalation than vegetable ingestion. Overall, vegetable ingestion and inhalation are the main exposure pathways for non-carcinogenic and carcinogenic risk. Consequently, future risk assessment should focus on the impact of hazardous substances on children, as well as the health risk associated with ingestion of vegetables and inhalation. Our findings will provide basic information for proposing measures of environmental risk prevention during the recycling of spent LABs, for example, controlling of As in exhaust gas emissions.