Exhaust Gas Components Research Articles

Neutralization of Acidic Exhaust Gas Components by Overbased Additives in Marine Oils: Effects of the Acid Composition on the Neutralization Mechanism

Neutralization of Acidic Exhaust Gas Components by Overbased Additives in Marine Oils: Effects of the Acid Composition on the Neutralization Mechanism

Analysis of the noise emission generated by a drive unit powered by mixtures of diesel oil and fatty acid methyl ester

The sound generated by drive units is one of the aspects that are addressed in sustainable transport development strategies. The regulations of the European Union, which indicate the ecological aspect of the use of internal combustion engines as one of the most important, also refer to the level of sound emission generated by these engines. The use of alternative fuels to power combustion engines allows not only to reduce the toxic components of exhaust gases, but also to reduce the noise they generate during operation. The manuscript presents the study of a drive unit powered by mixtures of diesel oil and fatty acid methyl esters, in which the software regulations of the control system were modified. Studies have shown a decrease in the level of sound emission when powered by alternative fuels.

ЭКОЛОГИЧЕСКИЕ АСПЕКТЫ ПРИ ЭКСПЛУАТАЦИИ БЕНЗИНОВОГО АВТОМОБИЛЯ С АНТИТОКСИЧНОЙ СИСТЕМОЙ

In the Russian Federation, unlike the European countries, where the Euro-6 standard is in effect and introduction of Euro-7 is expected until 2025, the Euro-5 standard has been adopted and the possibility of introducing Euro-6 is only being formed, but the production and technical infrastructure of the service is not ready for this. The article defines the main parameters characterizing the qualitative and quantitative difference of the fuel-air mixture and their effect on the output parameters of exhaust gas toxicity, examines in detail the areas of change in toxicity parameters when varying the main operating modes of the engine, analyzes the maximum and minimum values of toxicity parameters and possible areas of their displacement in case of changing the technical condition of engine systems. As a result of theoretical studies, it was revealed that concentration of toxic components of exhaust gases before entering the converter may be several times different from mode to mode. Such operation at the limit of the maximum degree of conversion of the catalytic converter accelerates its aging, leads to the loss of operational properties and, as a result, to deterioration in the environmental safety of the car.

APPLICATION OF BIO ADDITIVES IN DIESEL FUEL TO REDUCE CO, CH, SMOKE EMISSIONS IN AGRICULTURE

As part of the reduction of environmental emissions of tractors, combines and agricultural machinery when performing work in the agroindustrial complex, including in closed complexes for the cultivation of animals (livestock farms). The article presents proposals to improve the environmental characteristics of the diesel engine used in tractors of the agroindustrial complex of the Russian Federation. The effectiveness of the use of bioadditives from rapeseed oil for diesel engines is considered. The main directions of reducing emissions of toxic components of exhaust gases due to the addition of rapeseed oil to diesel fuel are indicated. The necessity of using bioadditives in diesel fuel to reduce emissions of CO, CH, and exhaust gases from diesel tractors when operating indoors is substantiated. A mixed fuel was used for the research. To get a mixed fuel, we mixed diesel fuel (DT) with rapeseed oil (RM). Based on the performed preliminary studies and these works, mixed fuel was prepared in the following proportions - 25% RM : 75% DT, 50% RM : 50 %DT, 75%RM : 25%DT. Rapeseed oil was obtained at ZAO Zelenogradskoye in the Pushkinsky district of the Moscow Region. The farm produces rapeseed seeds for the production of rapeseed oil, which is later used both for the confectionery industry and for livestock feed. Experimental studies have shown that the lowest content of CO, CH, in exhaust gases from diesel engines running on biofuels (25% RM:75% DT) and (50% RM:50% DT).

Modelling the Effects of Euro 7 Emission standard on Passenger Car Emissions in Germany

Road traffic represents a significant source of air pollution and greenhouse gases, particularly in urban areas. A new emission standard for passenger cars – Euro 7, coming into force in 2025 - is currently elaborated at European level to improve the air quality situation and thus the prerequisite for human well-being in the EU. The legislative proposal is expected to be published in 2022. This paper focusses on the evaluation of the effectiveness of Euro 7 standard with regard to vehicle fleet emissions in Germany. To this end, emission trend scenarios were generated for relevant exhaust gas components by applying the TREMOD model. Hereby, a strong reduction potential becomes apparent for hydrocarbon and nitrogen oxide emissions up to 2035. Assumptions laid down in this study need to be verified with real-world emission data when the new emission standard comes into force.

Experimental Evaluation of the Effect of Replacing Diesel Fuel by CNG on the Emission of Harmful Exhaust Gas Components and Emission Changes in a Dual-Fuel Engine

The constant development of civilization increases environmental pollution as a result of industrial activity and transport. Consequently, human activity in this area is restricted by regulations governing the permissible emission of harmful substance components into the environment. These include substances emitted by combustion engines, the use of which remains high in many industries. Consequently, research is being conducted to reduce the emissions of harmful exhaust components from existing and newly manufactured internal combustion engines. This research presents a used semi-truck engine, in which an innovative Compressed Natural Gas (CNG) supply system was applied. Using this fuel supply installation allows a mass exchange of the base diesel fuel to natural gas of up to 90%. The study evaluated the effect of the diesel/CNG exchange ratio for different engine operating conditions (engine load, speed) on the concentration of toxic components, such as CO, NO, NO2, NOX, as a sum of NO, NO2, CH4, C2H4, C2H6, C3H8, NH3, and CH2O. The use of a dual-fuel system had a positive effect on the emissions of some harmful exhaust components, even in an engine from a vehicle that had been running for many years on diesel and at high mileage, but, simultaneously, the emissions of some harmful exhaust gas components increased.

A Module for Calculating Pollutant Mass Emissions Produced by Traffic Flows

Introduction.Road transportation is increasingly becoming the main source of air pollution in cities. The problem of assessing air quality and modeling the dispersion of pollutants in the atmosphere requires improved models and methods. In particular, modern literature justifies the need to estimate the presence of particulate matter in the atmosphere along with the components of exhaust gases. Air pollution in residential zones should be comprehensively assessed using algorithmic and software support, taking the main factors of pollution into account.Aim.Development of an algorithm and its software implementation for calculating pollutant mass emissions released by traffic flows. The developed algorithm can be used for modeling the level of urban pollution.Materials and methods.The approaches of measurement theory, systems theory, statistical analysis, and mathematical modeling were applied.Results.The methods currently used for assessing the impact of urban road network characteristics on air pollution levels were analyzed. The existing approaches to road classification were considered. Significant characteristics affecting pollutant emissions were identified, including those related to road construction, traffic flows, and urban environment. An algorithm and a software module for calculating pollutant mass emissions released by traffic flows were developed.Conclusion.The developed module for calculating pollutant mass emissions released by traffic flows comprises an integral part of a system for modeling atmospheric air pollution in urban residential areas. The developed software can be used in environmental monitoring, assessment, and forecasting of air pollution to identify areas of concern and implement effective managerial solutions.

A Comparative Study of Emission Reduction Performance of Rare Earth Hydroxide Fuel Additives on Marine Diesel Engines

To deal with the environmental pollution caused by diesel engine exhaust gas, this paper calls for the use of fuel additives to improve the fuel quality or combustion quality to reduce the generation of harmful components in diesel engine exhaust gas. Based on the excellent REDOX capacity of rare earth elements, rare earth hydroxide is adopted as fuel additive. Firstly, the rare earth hydroxide is prepared, the contributory factors are analyzed, and the properties are characterized. Then through the building diesel engine test platform, different concentrations of rare earth hydroxide additives (60 mg/L, 80 mg/L and 100 mg/L) are respectively added to 0# diesel oil to make three kinds of oil samples, and the comparison test is conducted to compare with 0# diesel oil. The emission reduction ability of rare earth hydroxide additives is tested by measuring the content of harmful components in diesel exhaust gas. The experimental results show that the emission reduction performance of lanthanum hydroxide is better than that of cerium hydroxide, the 80 mg/L is the optimal amount of lanthanum hydroxide additives, its maximum reduction of NOX, CO and HC emissions is 29.3%, 40.0% and 45.7% respectively, and its maximum increment of PM emissions is 9.5%. Therefore, suitable additives can be selected according to actual needs of PM emission.

IMPROVMENT OF ENVIRONMENTAL PERFORMANCE TWO-STROKE DIESEL DURING OPERATION

The development of world shipping is taking place in the context of ever-increasing requirements to reduce the concentrations of toxic components of gaseous combustion products of hydrocarbon fuels. Concentration limits for these substances are regulated in accordance with Appendix VI of the MARPOL 73/78 Convention. Among the controlled components of diesel exhaust gases, nitrogen oxides are the most dangerous for humans and environment. However, a decrease in the content of nitrogen oxides is inevitably associated with limitations on the maximum cycle temperature, that is, thermal efficiency, and hence with a deterioration in the fuel efficiency of the engine. At the moment, in order to reduce emissions of nitrogen oxides by large transport diesel engines, the most widely used is the recirculation of exhaust gases into the air receiver. A significant disadvantage of using this scheme is the need for cooling the exhaust gases and their additional purification, which leads to an increase in the weight and size characteristics of the system and to its rise in price. Therefore, to reduce its cost, it seems logical to combine exhaust gas recirculation with other ways to reduce nitrogen oxide emissions. For engines in operation, one of these methods is to change the angle of fuel injection. It can be assumed that the later the fuel is injected into the cylinder, the lower the temperature of the air charge will be and, accordingly, the lower the maximum combustion temperature, and hence the amount of nitrogen oxides. The calculation of nitrogen oxide emissions was simulated for the main engine MAN-B&W 7S50MC-C installed on the vessel "LILA SHANGHAI". Initially, the model created using the AVL-BOOST package was verified based on the available indexing results. After verification, the calculation of emissions of nitrogen oxides NOx was made with a variation in the angle of the start of fuel combustion at the nominal mode. The composition of the gases in the receiver was taken unchanged. As the fuel combustion start angle shifted further from the TDC, deterioration in fuel efficiency and a drop in cylinder power were observed, while reducing the mass of emitted nitrogen oxides NOx. However, it can be said that the environmental friendliness of an engine improves much faster than its fuel and power characteristics deteriorate. The above calculations show that for engines already in operation, changing the fuel injection angle makes it possible to reduce nitrogen oxide emissions. Therefore, this approach can be combined without much difficulty with other methods, thus reducing the cost of environmental improvement of the engine.

Analysis of the Possibilities of Reduction of Exhaust Emissions from a Farm Tractor by Retrofitting Exhaust Aftertreatment

The paper evaluates particulate matter emissions and exhaust gas components from retrofitted engines of non-road vehicles measured under actual operating conditions. The content is divided into three main parts: formation of guidelines, production of the filter and emission tests. The obtained results clearly indicate excess PM and PN emissions from the engine under actual operating conditions when compared to the limits outlined in the type approval standards. Moreover, it was observed that the actual conditions are reflected to a very small extent at the points included in the stationary homologation test cycle. Based on these observations, the authors decided to modify the stationary test cycle. The measured exhaust gas compositions and their mass flow rates were used to create the geometry of the newly developed filter. The paper contains detailed results of the relative specific exhaust emissions of particulate matter and gaseous components at individual engine operating points. The exhaust emissions analysis made it possible to draw conclusions regarding the operation of the newly designed system. One of them is that fitting a metal-support particulate filter in the exhaust system significantly contributes to reducing the exhaust emissions.

Comparison of the Combustion Process Parameters in a Diesel Engine Powered by Second-Generation Biodiesel Compared to the First-Generation Biodiesel

The use of biofuels to power compression–ignition engines makes it possible to reduce emissions of certain harmful components of exhaust gases. The purpose of this study was to determine the influence of second-generation biofuels on the course of indicator graphs and heat release characteristics of the Perkins 1104D-44TA compression–ignition engine. For comparative purposes, the same tests were carried out by feeding the engine with first-generation biofuel and diesel fuel. Babassu butyl esters (BBuE) were used as the second-generation biofuel. The second fuel was a first-generation biofuel—rapeseed oil methyl esters (RME). Analysis of the results made it possible to draw conclusions about the effect of using 2nd and 1st generation biofuels on the parameters of the combustion process. When the DF engine was powered, the lowest fuel dose per work cycle was obtained. In the case of RME and BBuE fuels, it depends on the engine load. For low loads, higher consumption is for RME, and for higher loads, fuel consumption for BBuE in-creases most often. This is due to the lower calorific value of the esters. The results of these tests indicate that feeding the engine with BBuE and RME fuel in most loads resulted in higher maximum combustion pressures compared to feeding the engine with DF which may be directly related to the higher cetane number of these fuels compared to DF and the oxygen content of these fuels. Feeding the engine with BBuE and RME esters compared to DF did not result in large differences in the maximum heat release rates HRmax. However, the values of the first and second maximum heat release rates x1max and x2max, in addition to the type of fuel, are strongly influenced by the operating conditions, especially the engine load. Analyzing the combustion angles of 5, 10, 50, and 90% of the fuel dose, it can be seen that feeding the engine with BBuE and RME esters for most measurement points results in faster combustion of the fuel dose compared to DF.

Regulation of organic hydrocarbon pollutants in coal volatiles combustion with CO2 addition

Considering the important effect of coal volatiles combustion on coal-fired organic pollutants formation, coal pyrolysis gas was selected as fuel in this work. Spatial profiles of light hydrocarbons and aromatic hydrocarbons in counterflow diffusion flames (CDFs) were detected by gas chromatography and gas chromatography-mass spectrometer, combined with chemical reaction kinetic analysis. As the main component of exhaust gas, CO2 could significantly affect hydrocarbons formation in flames. By adding CO2 to the oxidizer of CDF, the regulation of CO2 addition on organic products during coal pyrolysis gas combustion was studied. The results showed that the dilution/thermal and chemical effects of CO2 all decreased the mole fractions of H, thereby inhibiting the formation of acetylene (C2H2), propargyl (C3H3), propyne (PC3H4), 1,3-butadiene, vinylacetylene, diacetylene, benzene (C6H6), toluene and naphthalene in the flame. With CO2 addition, the path from C2H2 to PC3H4 was inhibited, and less C3H3 formed C6H6 through self-recombination, while more favored to form C6H6 through fulvene. Decrease in the concentration of above-mentioned soot precursors indicated that adding CO2 could effectively inhibit the emission of organic pollutants during coal combustion process.

Oxygenated Diesel Fuels and Their Effect on PM Emissions

Particulate matter (PM) emitted by diesel engines is one of the most harmful components of exhaust gases, including its carcinogenic effect. Due to the widespread use of diesel engines, the health effects of PM emissions affect millions of people around the world. At the same time, diesel particulate matter is characterized by a very complicated structure and mechanisms of formation compared to other exhaust gas components. It is obvious that PM emissions should be limited by all means. This article focuses on the reduction of PM emissions with the use of oxygenated fuels. The mechanisms of oxygenated fuels influence on the soot formation process in the working process of diesel engines have been discussed. The importance of the chemical structure of oxygenated compounds for the effectiveness of PM emissions reduction was considered. The results of empirical research on the influence on PM emissions of oxygenated fuels containing 12 oxygenates from chemical groups such as glycol ethers, maleates, carbonates and butanol were analyzed. The emissions tests were undertaken on a diesel passenger car over the NEDC and FTP-75 cycles. The results showed a high potential of oxygenated fuels in PM emissions reduction, even at a low oxygenates concentration of 5% v/v; namely, PM emissions were reduced by up to 32%. According to tests results, 1% of oxygen in the fuel resulted in an average reduction of PM emissions by 7% to 10%. In the view of already limited possibilities of modifying conventional parameters of diesel fuels, the use of oxygenated compounds is a promising way to trade on the potential of fuels in PM emissions reduction.

Environmental control of the technical condition of electromagnetic nozzles of internal combustion engines

Harmful motor vehicle emissions are often the primary source of urban air pollution worldwide. Incorrectly serviced high-mileage motor vehicles emit significantly more harmful substances into the atmosphere than established by accepted standards. This paper presents an algorithm for the process of diagnostics and analysis of the technical condition of the fuel supply system elements for internal combustion engines (ICE) by means of selective sampling of exhaust gases. A gas analyzer system allows for the simultaneous monitoring of the 4 components of exhaust gases: CO, CH, O2 and CO2, assessment of the air-fuel ratio and internal combustion engine crankshaft rotation speed. Studies were carried out on an engine and a series of malfunctions were created artificially, by means of installing faulty elements and additional elements simulating different degrees of wear on the ICE systems. The study resulted in the development of a method and a hardware and software system. These allow for the test regimes to be established, in order to determine the failure of ICE systems which affect the composition of the exhaust gas.

Experimental Studies of the Effect of Air Filter Pressure Drop on the Composition and Emission Changes of a Compression Ignition Internal Combustion Engine

This paper presents an experimental evaluation of the effect of air filter pressure drop on the composition of exhaust gases and the operating parameters of a modern internal combustion Diesel engine. A literature analysis of the methods of reducing the emission of toxic components of exhaust gases from SI engines was conducted. It has been shown that the air filter pressure drop, increasing during the engine operation, causes a significant decrease in power output and an increase in fuel consumption, as well as smoke emission of Diesel engines with the classical injection system with a piston (sectional) in-line injection pump. It has also been shown, on the basis of a few literature studies, that the increase in the resistance of air filter flow causes a change in the composition of car combustion engines, with the effect of the air filter pressure drop on turbocharged engines being insignificant. A programme, and conditions of tests, on a dynamometer of a modern six-cylinder engine with displacement Vss = 15.8 dm3 and power rating 226 kW were prepared, regarding the influence of air filter pressure drop on the composition of exhaust gases and the parameters of its operation. For each technical state of the air filter, in the range of rotational speed n = 1000–2100 rpm, measurements of exhaust gas composition and emission were carried out, as well as measurements and calculations of engine-operating parameters, namely that of effective power. An increase in the pressure drop in the inlet system of a modern Diesel truck engine has no significant effect on the emissions of CO, CO2, HC and NOx to the atmosphere, nor does it cause significant changes in the degree of smoke opacity of exhaust gases in relation to its permissible value. An increase in air filter pressure drop from value Δpf = 0.580 kPa to Δpf = 2.024 kPa (by 1.66 kPa) causes a decrease in the maximum filling factor value from ηυ = 2.5 to ηυ = 2.39, that is by 4.5%, and a decrease in maximum power by 8.8%.

Hydro-treated vegetable oil as a potential biofuel for self-ignition engines

Hydro-treating vegetable oils or animal fats is an alternative process to esterification for the production of biodiesel. Hydro-treated products are also called renewable diesel fuels. Hydro-treated vegetable oils (HVO) do not have the harmful effects of FAME biodiesel such as increased NOₓ emissions, deposit formation, storage stability problems, faster aging of the engine oil or poor cold performance. HVO are straight chain paraffinic hydrocarbons which are free of aromatic hydrocarbons, oxygen and sulphur and have a high cetane number. In the article below, the authors conduct a comprehensive analysis and evaluation of the possibility of running compression-ignition engine on the hydro-treated vegetable oil, which is a second-generation biofuel. On its basis, the information on the assessment of emissions of selected toxic components of exhaust gases and pollutants of the injection system when the engine is powered with this type of fuel, was systematized. The article ends with conclusions from the conducted analyses.

Thermal desorption behavior of fluoroquinolones in contaminated soil of livestock and poultry breeding

As a kind of typical veterinary drug, fluoroquinolone antibiotics (FQs) are widely used in the field of livestock and poultry breeding, but these FQs escape to surrounding soil through various pathways, polluting soil through long-term accumulation. Current study proposed a clean technology named thermal desorption to deal with FQs contaminated soils. It was observed that time, temperature and soil particle size were the critical factors in FQs thermal desorption. Results of the study showed that higher temperature was more effective in the removal of FQs, while removal of FQs attached with finer particles was more difficult compared to coarse particles. Fine soil particles (0.6–0.85 mm) were decontaminated up 99.4% when treated with 400 °C for 60min. Thermal desorption of FQs from contaminated soil was governed by first-order kinetics. Based on the detection of exhaust gas components, a possible thermal desorption mechanism was proposed. Study suggested that thermal desorption was a clean and effective remediation method to treat FQs-contaminated soils without generating any further waste.

A Review of the External and Internal Residual Exhaust Gas in the Internal Combustion Engine

Efficiency and emission reduction are the primary targets of internal combustion engine research due the large number of vehicles in operation and the impact of emissions-related pollution on human and ecosystem health. Harmful components of engine exhaust gases include nitrous oxides (NOx), carbon dioxide, hydrocarbons, and particulate matter. NOx emissions in particular are associated with significant health threats. The recirculation of exhaust gases can reduce NOx emissions and improve engine efficiency when combined with other advanced techniques. On the other hand, the residual exhaust gas also effects on the quality of lubricating engine oil and therefore causes an increase in engine piston ring wear. In this review paper, the effects of external and internal exhaust gas recirculation on the performance and emission characteristics of diesel, gasoline, and alternative fuel engines are summarized and discussed in detail. Because it is difficult to estimate the internal residual exhaust gas in the combustion engine by doing experiments. This review paper introduces control strategies and prediction methods for internal and external exhaust gas recirculation.

Investigation on ammonia removal efficiency of selective catalytic reduction based emission control system

Increasing concern about rising pollution levels and stringent emission regulations have led to the development of selective catalytic reduction (SCR) based after-treatment systems for reducing NOx emissions. SCR system has a complicated working principle involving chemical reactions and under certain operating conditions, side reactions take place, resulting in ammonia/urea slip from the exhaust outlet. In this article, a three-dimensional model of the SCR system is developed using CATIA v5 software and geometric design validation is conducted to ensure continuous flow without any backpressure rise. CFD study is conducted by considering chemical reactions and discrete phase modeling for determining variation mass fraction of various exhaust gas components related to SCR system along with the emission control system. The results of the study showed that the developed SCR system has average ammonia removal efficiency of 95% ensuring the effective working of the SCR system to meet emission norms.

Ecological aspects of using mixtures of canola oil with n-hexane in diesel engine

The article discusses the results of research on the use of canola oil and canola oil with the addition of n-hexane in a compression-ignition engine. An engine with a Common Rail injection system was tested in real traffic conditions on the road and on a chassis dynamometer. The tested fuels were fed to the engine by an additional fuel supply system. An analysis of the effect of the addition of n-hexane on the emission of the main components of toxic exhaust gases was carried out. The proposed solution may contribute to extending the service life of currently used compression ignition engines due to the improvement of the ecological properties of this type of drive sources.