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Catalytic converter can contribute to global warming and to reduce emission of vehicle of engines. The transesterified Avocado oil is used as a fuel in a four-stroke diesel engine. The test fuels were prepared in different blends such as B10, B20 and B30. The aim of research work is to reduce emission and to improve the performance of the DI diesel engines, produced by the biodiesel blend. The catalyst materials used in catalytic converter are relatively low cost in comparison with conventional catalyst such as Palladium and Platinum. Basalt fiber is used as a substrate which is absolutely non-combustible. The performance and emission analysis are made.

Research on the effects of the use of the range extender developed for a small commercial electric vehicle was presented in this paper. The range extender has a maximum output power of 2.65 kW. The developed auxiliary power unit consists of a three-phase generator propelled by an industrial low-power spark-ignition engine. The exhaust system was improved using a more efficient muffler. The implemented motorcycle muffler has a three-way catalyst (TWC) integrated inside. The use of the more advanced exhaust system aimed at reducing noise and exhaust emissions of the range extender. The efficient operation of the three-way catalytic converter requires a stoichiometric air-fuel ratio. To enable desired air-fuel ratio a fuel system was modified. In the first stage of research, the effects of improvements of the exhaust system on the range extender noise emissions were quantified. The next step covered the research of the fuel conversion efficiency, the exhaust gas composition, and the efficiency of conversion of the three-way catalyst. A significant decrease of noise and toxic gas emissions and an increase in the fuel conversion efficiency were revealed. The mentioned research was conducted in stationary conditions. After that, in the final part research of the running vehicle with the range extender on was made. The beneficial outcome of these tests enabled the development of a set of rules of the control of the range extender.

The catalytic converter is a device which converts harmful exhaust gases from internal combustion engine into harmless gases. Global warming and air pollution are a buzz in today’s scenario. Greenhouse gasses are responsible for global warming. Carbon dioxide, which contributes to being the single most significant greenhouse gasses emission, comes from the exhaust of an automobile. Catalytic converter plays a vital role in the reduction of such greenhouse gasses. The objective of the present study is to examine an automobile catalytic convertor to present a detail and comprehensive report on the key parameters affecting the flow uniformity inside the converter and thus attempting to achieve minimum pressure drop across the converter to reduce the backpressure. The catalytic converter geometry is modified to increase the conversion efficiency of the converter. The results reported in the latter part of this paper gives a good insight about the recirculation zones created in the base and also velocity and pressure plots to find a solution for uniform flow within the monolith and also achieved a reduction in pressure drop of 3.7 Pa.

Studies on the influence of applying various technologies for combustion knock reduction have been presented in the paper. Among others, investigation concerning the following: over-expanded cycle, variable valve timing, internal and exhaust gas recirculation, leaning the combustible mixture and cooling the in-cylinder charge were of the interest. The research works were focused on impact of these technologies on both knock intensity reduction, and engine performance and toxic emissions. Results presented in the paper were coming from experimental investigation based on in-cylinder combustion pressure data acquisition. Additionally, knock intensity calculation methods were discussed. They are based on incylinder combustion pressure pulsations. Combustion knock intensity expressed by the maximum peak of the incylinder pressure pulsations shows a strong negative correlation with both the EGR ratio and relative equivalence ratio – lambda. With respect to a catalytic converter installed on the exhaust pipe line, applying EGR appears as better solution for knock reduction then leaning the combustible mixture because the catalytic converter needs stoichiometric mixture for effective NO x reduction. Furthermore, application of the over-expanded cycle to the hydrogen or coke gas fueled IC engine significantly reduces intensity of potential knock by 50 % in comparison to Otto cycle for all loads. Additionally, over-expanded cycle contributes to increase in engine thermal efficiency. Summing up, all the presented measures and technologies can be successfully implemented into practice in stationary engines as well as in traction engines, both of them working on either natural gas or gaseous renewable fuels.

Purpose: The purpose of this study is to analyse the modelling of exhaust gas flow patterns with variations in pressure, number, and shape of filters on the catalytic converter. Design/methodology/approach: The research method used is a simulation using ANSYS, which starts by creating a converter catalytic model with pressure variations: (0.5-1.5 atm), number of filters: (2-5), and the form of filter-cut/filter-not-cut. Findings: The decrease in velocity is caused by non-uniform velocity in the exhaust gas flow that occurs when passing through a bend in the filter-cut that serves as a directional flow to create turbulence. Filter-cut type tends to have fluctuating pressure, turbulence flow pattern shape so that contact between filter and exhaust gas is more effective. Based on the analysis of flow patterns, the speed and pressure of the 5 filter-not-cut design at a pressure of 0.5 are the best, while at pressure (1-1.5 atm) the type 5 filter-cut is the best. Research limitations/implications: This study is limited to filter-not-cut and filter-cut types with variations in the number of filters: 2, 3, 4, and 5, and the inlet pressure between 0.5-1 atm. Practical implications: The practical implications of this study are to find a catalytic converter design that has advantages in the effectiveness of exhaust gas absorption. Originality/value: The results show that the filter-not-cut and filter-cut types have the best effectiveness in the number of 5 filters. Filter-not-cut at the pressure of 0.5 atm and filter-cut at pressure (1-1.5 atm).

The issue of pollution is very paramount in the world, especially due to automobiles that run with diesel engine. Therefore, we intend to reduce the harmful exhaust from automobiles by fixing a filter system in between catalytic converter and muffler. Unlike catalytic converter this filter works in conditions even less than 800 ° Fahrenheit & it reacts with the combustion products irrespective of temperature. Also, this filter system is easy to remove and replace so that it does not require any special procedures or tests as in catalytic converter. The presence of chemicals like Al2O3, Zeolite, Charcoal enables the filter system to reduce CO, HC & NOX content in exhaust gas and a filter like HEPA reduces the particulate matter from 0.5 to 2.0 micrometre size. As monolith is used as substrate material here, it causes a uniform flow of exhaust gases over the entire area of the substrate. From this experimental work, we intend to reduce pollution and attain further Euro and Bharat standards

Air pollution a potential environmental problem is caused mostly by the burning of fuels both in the transport sectors and industrial sectors. Motor vehicles are one of the significant growing air pollution contributors who produce a considerable amount of volatile organic compounds (VOCs) and other pollutants. The rising concern about the environmental effect of the exhaust emission pollutants has led to the need for the development of progressively efficient catalytic converters and exhaust gas after-treatment systems. Mathematical modeling is an essential way to understand the processes occurring in the catalytic converter, and it plays a critical part in improving and designing the existing models. A mathematical model has been formed for both non-catalytic and catalytic reactions based on mass and heat transfer for the oxidation of VOC ethane. Modeling equations have been solved with an implicit scheme, and numerical calculations have carried out using Matlab software. The results have been compared, obtained from the two reactions mechanisms.

Automobiles throughout the world are the primary consumers of fossil fuels, which emit toxic gases when burnt; including HC, CO and NOx. Catalytic converters were developed to detoxify these gases into less harmful gases such as carbon dioxide and H2O.In this paper, the development of a catalytic converter for efficient emission reduction is presented. The results are presented after performing Computational Fluid Dynamics (CFD) on the proposed catalytic converter. In this catalytic converter Two Different materials used they are stainless steel wire mesh and ceramic stones at time and we are conducted tests with catalytic converter at different blended fluids and engine speeds such as methane, ethane and 1700,1900 RPM.3D modeling done by CATIA parametric software And analysis done in ANSYS software.

The catalytic converter is used in the engine setup in order to meet the emission limits. Catalytic converter comprises of a monolith type substrate and housing for its connection with engine exhaust. Catalytic converter housing geometric parameters such as inlet cone angle, diameter, position of catalytic monolithic and the shape of the inlet cone are vital importance for achieving better flow efficiency in the exhaust system. These parameters also influence manufacturing process such as die design, material properties, etc. In this paper, finite element analysis simulation is performed for different inlet cone angles to understand its significance. Material considered for the simulation is Stainless Steel 304 with a sheet thickness is 1 mm and co-efficient of friction between the sheet and die material is 0.15. Nonlinear stress-strain curve for sheet material is determined through experimentation and the same is given as input for material property. Simulation results for different inlet cone angle have been evaluated using the Forming Limit Diagram. From investigation 600 inlet cone angle is identified as optimized process parameters in terms of manufacturing aspect.

The growing demands for improving air quality, the increased cost of crude oil, and its critical level of availability move the automobile industries in search of alternative fuels. The past and current civilizations are making the earth a vulnerable place to live for future generations by polluting and extinguishing all natural resources. The increase in industrialization and motorization have made the situation still worse. To improve the air quality, cope up with emerging demand, and reduce the cost of fuel the whole world is moving towards alternative fuels. In this research, alcohol is considered an alternative fuel since alcohols are oxygenated fuels and having lesser carbon content. Hence there is a considerable amount of reduction in regulated emissions (HC, CO2, CO, and NOx). Alcohols are renewable and preparation process is simple. The usage of alcohol will lead to unregulated emissions like aldehydes, alkanes, etc. In this research, in order to reduce both regulated and unregulated emissions, a novel shaped catalytic converter is designed and fabricated using advanced manufacturing process. In this, the conventional catalyst like platinum, palladium, and rhodium catalysts are replaced with vanadium and cobalt to reduce the cost and the use of costlier earth metals. The analyses were conducted on a SI engine setup utilizing gasohol (gas + ethanol) fuel blends in with three distinctive fuel proportions such as E10 (gasoline 90% ethanol 10%) and 20% (gasoline 80% ethanol 20%) and with 100% gasoline E0. Both regulated and unregulated emissions was measured and conversion efficiency of the newly manufactured novel catalytic converter was also determined.

The ever-increasing demand for transport is sustained by fossil fuel-based internal combustion (IC) engines fitted with catalytic converters (CCs) while alternative options and fuels are still emerging. Biodiesel seems to be a potential alternate to diesel, but the formation of NOx and smoke are major issues. This study aimed to explore the effect of B100 Pongamia biodiesel on the performance of CCs and to assist the designers of compression ignition engines. This study included a comparison of deposits on the catalytic converter (CC) in the cases of diesel fuel and biodiesel. Forensic examination of the spent CCs after 250 h was performed by characterization using SEM/EDS. The amount and composition of the deposits were compared for the diesel and biodiesel, and the effectiveness of the CC. The study revealed that the efficiency of the CC increased in biodiesel. The amount of soot and deposits was greater at the engine side of the spent CC with diesel, including the atomic percentage (At. %) of C, while the minimum deposits and C At. % in the spent CC were at the exhaust side with biodiesel. Oxygen content in the deposits was greater in biodiesel. The efficiency and effectiveness of the CC increased with the biodiesel.

A computational fluid dynamics model, consisting of a mixing chamber coupled with a catalytic converter, is developed for the selective catalytic reduction (SCR) of NOx using urea. The NH3 required...

Methanol is commonly used as a hydrate inhibitor in gathering and transportation systems for natural gas streams containing H2S. While efforts are made to prevent carryover, some residual methanol can end up reaching downstream facilities. If residual methanol is still present in an acid gas stream after amine separation from sales gas, it normally undergoes quantitative conversion to CO and H2 in the front-end thermal reactor of the Claus sulfur recovery unit. However, if the Claus sulfur recovery unit is operating in a split-flow configuration in such a scenario, some acid gas, and the corresponding methanol, bypasses the thermal reactor and gets introduced directly to the first catalytic converter. While the fate of methanol in the thermal reactor of a Claus sulfur recovery unit has been established, an understanding of methanol reactivity and influence within the first catalytic converter is lacking. To shed light on this issue, we have performed a series of laboratory experiments, simulating field conditions, that elucidate the effect of methanol in the first catalytic converter of a Claus sulfur recovery unit, which can contain titania (TiO2) and/or alumina (Al2O3) catalysts. The results obtained identify that methanol is converted to CS2, via a CH3SH intermediate, which is then hydrolyzed to form H2S and CO2. Strategically designed experiments support this methanol conversion mechanism over both Al2O3 and TiO2. Although catalyst discoloration was observed in some experiments with methanol, no significant catalyst deactivation was observed, where CS2 conversion was monitored as a method for assessing activity once steady-state had been reached. Results from catalyst surface area analyses agreed with these observations. Finally, it was also found that there was no change in the carbon content of the sulfur formed during experiments where methanol was present when compared to control experiments without methanol addition to the feed.

State-of-the-art catalytic converters need an ever-high amount of precious-metal catalysts to meet stringent emission regulations. This research reveals an alternative design based on micro-structured ceramic hollow fibre substrates, yielding high conversion of pollutants at low catalyst costs, as well as a unique benefit of low pressure-drop, leading to high engine performances.

To reduce cold-start emissions, a thermal energy storage (TES) system can be used in conjunction with the exhaust aftertreatment system. Phase change materials (PCM) can be used in the TES system to absorb the exhaust gas thermal energy, thus liquefying and storing it as latent heat. This allows storage of the exhaust gas thermal energy during the engine’s high-load conditions and gradually releases the thermal energy back to the catalyst substrate during the engine-off period. Based on the results, implementing a TES system into the diesel aftertreatment system has shown great potential in reducing a vehicle’s emissions, particularly for hybrid vehicles. This approach can assist the catalyst to activate the emissions’ conversion reactions straight after the cold-start. However, its effectiveness largely depends on the duration of the engine-off periods between the driving cycles. In this study, it was found that facilitating the heat transfer between the PCM and the catalyst can significantly improve the emissions’ reduction performance by avoiding the catalyst to light-out after the cold-start. A substantial improvement in the system’s thermal behaviour was observed by using PCM additives and metallic catalyst substrates to increase the system’s thermal conductivity. Although a TES system increases the aftertreatment cost and complexity, it can result in substantial emissions’ reduction over the vehicle’s operating life. This can also translate into reduced vehicle fuel consumption and CO2 emissions, as the emissions-related fuel penalty will be minimized.

Resumo Nas últimas décadas, diversos países adotaram ações para mitigar as emissões tóxicas dos automóveis e, principalmente, reduzir riscos à saúde pública. Pesquisas indicam uma relação estatisticamente significativa entre monóxido de carbono (CO) e doenças respiratórias. A regulamentação teve um papel vital na definição de metas e padrões que fomentaram o desenvolvimento tecnológico dos automóveis. O objetivo deste artigo é analisar o papel da regulamentação como indutora da inovação tecnológica ambiental na redução de emissões tóxicas de veículos leves fabricados no Brasil. Realizou-se uma pesquisa qualitativa descritiva de base documental. A difusão dessas tecnologias no Brasil mostra defasagem cronológica entre a implementação das fases da legislação Euro e do Programa de Controle da Poluição do Ar por Veículos Automotores (PROCONVE). Os resultados da pesquisa mostram que a regulamentação fomentou a difusão da inovação tecnológica ambiental, com a introdução de injeção eletrônica de combustível, catalisador e melhoria da motorização. Diante das mudanças identificadas, a regulamentação leva a um processo de balanceamento tecnológico entre as montadoras com ganho de escala, de modo a favorecer a difusão de tecnologias ambientais para mitigar as emissões de gases tóxicos.

[EN] Worldwide pollutant regulations applied to the transportation sector are progressively tightening the emission limits and widening the operating conditions of the type approval tests. As a result, the layout and thermal management of the exhaust system is becoming highly complex looking to achieve early catalytic converter activation. On this regard, the monolith meso-geometry plays a primary role to optimise the pollutants con -version efficiency. The geometrical characteristics simultaneously affect and trade-off multiple flow phenomena as the exhaust gas is transported through the channels. These include the bulk gas and internal pore diffusion towards the active sites in addition to the heat transfer including convection, radial conductivity and thermal capacitance. In this work, the impacts of the cell size, cross-section shape, washcoat loading and substrate material on CO and HC conversion efficiency have been investigated under representative real driving condi-tions. From the real driving conditions experimental data, the study decouples the influence of the washcoat loading from the cell size and material applying a catalytic converter model. Detailed expressions are provided for the calculation of the specific surfaces and heat and mass transfer parameters as a function of the cell and washcoat meso-geometry in square and triangular cells. Therefore, this work enables to identify the processes which govern the catalytic abatement of pollutant emissions. In particular, the role of the gas and washcoat specific surfaces is highlighted because of its importance on the optimization of the mass transfer process by means of a proper cell geometry selection. In parallel, the differences in the change of the CO and HC abatement patterns, which are explained by the characteristic CO emission spikes in accelerations and the HC accumulation, contribute to evidence the limitations on the conversion efficiency benefit that the optimum cell geometry and washcoat loading can provide., The authors acknowledge FEDER and Spanish Ministerio de Economia y Competitividad for partially supporting this research through project TRA2016-79185-R. Additionally, the Ph.D. student Maria Jose Ruiz has been funded by a grant from Universitat Politecnica de Valencia with reference number FPI-2018-S2-10.

Automobiles throughout the world are the essential shoppers of non-renewable energy sources, which radiate harmful gases when consumed; including HC, CO and NOx. Exhaust systems were created to detoxify these gases into less destructive gases, for example, carbon dioxide and H2O. In this paper, the development of a catalytic converter for efficient emission reduction is presented. The results are presented after performing Computational Fluid Dynamics (CFD) on the proposed catalytic converter. In this catalytic convertor Two Different materials used they are stainless steel wire mesh and ceramic stones at time and we are conducted tests with catalytic convertor at different blended fluids and engine speeds such as methane, ethane and 1800,2000 RPM.3D modelling done by CATIA parametric software And analysis done in ANSYS software.

The article focuses on numerical analysis and optimization of exhaust gasses flow in a catalytic converter which is one of the highly important components in the cogeneration unit produced by TEDOM a.s. The optimization deals with total pressure drop and gas distribution at the inlet of the converter. In the article, the description of geometry, computational mesh is presented as well as the summary of parameters used for the numerical analysis. Findings from study of dependency of optimizable parameters on shape and size of the chamber represented the basis for evaluation of the most suitable version of the chamber. All calculations were processed by ANSYS CFX 2020 R1 software.

The paper’s scope is devoted to atmospheric air protection based on developing mathematical models of catalytic processes to purify environmentally hazardous substances at gas mixtures in the proposed design converter. The existing mathematical models of catalytic processes on a solid surface have been analyzed, and the relevance of further research on the complex rendering of a description of catalytic reactions taking into account the interaction features «gas flow − solid surface − heat and mass transfer along the surface − transformation processes in the internal volume and on outlet surface is an eco-safe gas mixture». Based on the conversion’s theoretical description, a three-level model describing the constructed catalytic converter processes is proposed. The connection of theoretically grounded models with known phenomenological models of carbon monoxide oxidation is shown. The advantages of the three-level model of catalytic conversion as the basis for making decisions on improving the catalytic device structure are determined. Algorithms and software for modeling the catalytic purification processes of gas mixtures from technogenic dangerous objects have been developed. The advantage of the proposed mathematical models and algorithms is their high speed, the ability to automate environmental safety monitoring based on the developed information and software products, the qualitative and quantitative agreement of the obtained numerical results with the results of experimental studies.

The increasing diffusion of alternative mobility solutions, ranging from electric technologies to natural gas fueled vehicles (NGVs), has led to a progressive life-cycle analysis approach of their environmental impact in terms of greenhouse gases (GHGs) emissions. This new approach prompted a careful design of the NGVs catalytic aftertreatment system in order to minimize the catalytic converter carbon footprint as well as the unburned methane emissions at tailpipe. Here, a series of Pd/CeO2 methane oxidation catalysts were prepared by an environmentally friendly solvent-free method and compared to the commercial wet-synthesized state-of-the-art catalysts. Their application in NGVs aftertreatment systems was evaluated by testing powder catalysts and coated monolith cores for CH4 oxidation and steam reforming, which are the main methane abatement reactions occurring in a three-way catalyst (TWC) under lean and rich conditions, respectively. Pd/CeO2 catalysts prepared by mechanochemical synthesis initially displayed superior activity compared to their counterpart obtained by conventional wet impregnation, especially under lean oxidation conditions, but appeared less resistant to the industrial aging process after core washcoating. Lambda sweep experiments carried out under full gas composition proved that, despite needing further optimization in the washcoating and aging processes, the developed mild milling synthesis procedure is a viable way for the production of Pd/CeO2 based catalysts for natural gas TWCs.

Engine exhaust species such as nitrogen oxides (NOx), carbon monoxide (CO) and unburnt hydrocarbons (HC) are hazardous and pose a significant threat to the environment and the human health. Catalytic converter is installed in the engine exhaust manifold of modern vehicles for emission reduction. This device plays a significant role by simultaneous catalytic oxidation and catalytic reduction reactions. Catalytic converters themselves do not take part in chemical reactions but catalyse these reactions. There is a drastic reduction in CO, HC and NOx emissions in the exhaust, and these species are converted to harmless products exiting through the tailpipe. Catalytic converters are among the most developed and matured technologies to control exhaust emissions. Emissions concentrations of different emission species can be analysed upstream and downstream of the catalytic converter to evaluate their conversion efficiencies. Also, real-time catalyst temperatures can be determined by 1-D thermal modelling of the three-way catalytic converters. This chapter gives insights into the flow behaviour along with the transient temperature field across the catalytic converter, which helps understand overall working of the catalytic converter. Also, catalyst temperature distributions are discussed based on engine operating conditions in order to understand the effect of exhaust gas temperature on the catalytic converter efficiency.

The emissions of pollutants from vehicles are generally low but the numbers of vehicles increasing on the road therefore the environmental pollutions are also increases. About 35% of CO, 30% of HC and 25% percent of NOx produced into the atmosphere is from the transportation sector. These pollutants have adverse effects on the environment and human health. The emissions from vehicles are generally depends upon the air–fuel ratio. The control techniques for exhaust gas emissions are engine modifications, fuel pretreatment, fuel additives, exhaust gas recirculation (EGR), positive crankcase ventilation (PCV) and an application of catalytic converters. A catalytic converter is a device that converts more toxic exhaust gas pollutants into less toxic pollutants. There are different types of catalysts used in the automobile exhaust gas treatment like noble metal and base metals catalysts etc. The catalytic converter was effective and consistent for reducing the noxious tailpipe emissions so that it was developed for use in the trucks, buses, cars, motorcycles and other construction equipped. This paper will discuss about the different types of recent developments in catalysis for automobile exhaust pollution control.

The projected increase in the availability of gaseous fuels by growing popularity of household natural gas (NG) filling stations and the increase in the production of gaseous biogas-derived fuels is conducive to an increase in the use of NG fuel. Currently, natural gas in various forms (compressed natural gas (CNG), liquefied natural gas (LNG)) is popular in maritime, rail and road transport. A new direction of natural gas application may be non-road mobile machines powered by a small spark-ignition engine (SI). The use of these engines in the wood chippers can cause the reduction of machine costs and emissions of harmful exhaust gases. In addition, plant material chippers intended for composting in bio-gas plants can be driven by the gas they are used to produce. The biogas can be purified to bio-methane to meet natural gas quality standards. The article presents the design of the natural gas supply system, which is an upgrade of the Lifan GX 390 combustion engine spark ignition engine (Four-stroke, OHV (over head valve) with a maximum power of 9.56 kW), which is a common representative of small gasoline engines. The engine is mounted in a cylindrical chipper designed for shredding branches with a maximum diameter of up to 100 mm, which is a typical machine used for cleaning work in urban areas. The engine powered by CNG and traditionally gasoline has been tested in real working conditions, when shredding cherry plum (Prunus cerasifera Ehrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender4:189&ndash, 204. 1784)). Their diameter was ca. 80 mm, 3-metere-long, and humidity content ca. 25%. The systems were tested under the same actual operating conditions, the average power generated by the drives during shredding is about 0.69 kW. Based on the recorded results, it was found that the CNG-fuelled engine was characterized by nitrogen oxides (NOx) emissions higher by 45%. The other effects of CNG were a reduction in carbon dioxide (CO2), carbon monoxide (CO) and hydrocarbon (HC) emissions of about 81%, 26% and 57%, respectively. Additionally, the use of CNG reduced fuel consumption by 31% and hourly estimated machine operating costs resulting from fuel costs by 53% (for average fuel price in Poland: gasoline: 0.99 EUR/L and CNG: 0.71 EUR/m3 on 08 November 2020). The modernization performed by the authors ensured the work of the drive unit during shredding, closer to the value of stoichiometric mixtures. The average (AVG) value of the air fuel ratio (AFR) for CNG was enriched by 1.2% (AVG AFR was 17), while for the gasoline engine the mixture was more enriched by 4.8% (AVG AFR was 14). The operation of spark-ignition (SI) combustion engines is most advantageous when burning stoichiometric mixtures due to the cooperation with exhaust aftertreatment systems (e.g., three-function catalytic converter). A system powered by CNG may be beneficial in systems adapting to operating conditions, used in low-power shredding machines, whose problem is increased HC emissions, and CNG combustion may reduce them. The developed system does not exceed the emission standards applicable in the European Union. For CO emissions expressed in g/kWh, it was about 95% lower than the permissible value, and HC + NOx emissions were 85% lower. This suggests that the use of the fuel in question may contribute to tightening up the permissible emission regulations for non-road machinery.

The objective of this investigation is to reduce the NOx, CO and HC emissions by using catalytic converter and exhaust gas recirculation. The EGR is to reduce the NOx emissions, and catalytic converter reduces the CO and HC emissions. The experimental study was carried out in a four-stroke single cylinder spark ignition engine. The experimental results show that appreciable reduction of NOx by 40% for every 2.5% EGR introduction, while CO and HC emission level increases to certain level. The combined effect of EGR and catalytic converter simultaneously reduce the CO, HC and NOx emissions. The emission parameters were analysed and compared with the pure gasoline operation

Since converter performance is a complex function of operating conditions, converter geometries, and catalyst properties, an empirical approach to the problem can be very costly and time consuming; thus mathematical modeling promises to be helpful in the development of catalytic converters with improved warm-up performance. US federal regulations of automobile exhaust emissions are based on pollutant emissions measured while driving a vehicle over a prescribed driving schedule referred to as the Federal Test Procedure. The validity of the model was evaluated by comparing measured and predicted cumulative emissions of CO leaving the converter during the cold-start portion of vehicle emission tests. The parametric sensitivity results discussed so far were based on the inlet exhaust gas conditions of the same vehicle that was used for our model verification studies. The major assumptions invoked in the development of the model are a uniform flow distribution at the monolith face, and adabatic operation of the converter.

Reactor models and computer simulations can play an important role in meeting the new challenges in the area of optimal catalytic converter design. The most comprehensive treatment of single-passage monolith models can be found in the now classical work of Young and Finlayson. Although catalytic monolith reactors have been used on a large scale in automobile emission control since 1975, several questions concerning optimal design and transient performance of such reactors remain unanswered. Various design options for improving the light-off performance of catalytic converters were investigated by Oh and Cavendish. The 1990 amendments to the Clean Air Act mandate further improvements in catalytic performance by requiring that the life of automobile converters be extended from 50,000 to 100,000 miles and by reducing the levels of allowable pollutant emissions. The strong dependence of Nusselt and Sherwood numbers on axial position was a major result of the comprehensive study by Young and Finlayson.

NOx emissions from vehicles have been a substantial cause for concern due to their impact on urban air quality. In particular, despite reducing levels of permitted emissions legislatively, such reductions have not been observed in the real world. In this work, NOx emissions from three vehicles&mdash, a Euro 5 car, a Euro V hybrid bus, and a Euro VI&mdash, bus have been measured in real driving conditions (and in the case of the buses&mdash, in full passenger service). A recently developed high spatio-temporal resolution technique combining very fast (10 ms) NOx measurement with differential GPS accurate to 1 cm allows these emissions to be resolved to a distance of less than 10 cm (worst-case&mdash, dependent on vehicle speed). The results show that acceleration events for the vehicles play a significant part in their total NOx emissions. In addition, standard events such as a speed bump and a bus stop are analysed. The temperature of any aftertreatment (catalytic converter) to reduce NOx emissions is also observed to be of substantial significance. At idle, the passenger car was observed to near-double its NOx emissions when the air conditioning was switched on. Finally, the real driving conditions are compared to the legislative compliance cycles for the certification of the buses, and those results used to further understand the observed NOx emissions.

Compressed natural gas is an alternative green fuel for automobile industry. Recently, the Indian government is targeting to replace all the conventional fuel vehicles by compressed natural gas (CNG) automobiles due to its several merits. Still, the presence of a significant amount of CO, CH4, and NOx gases in the CNG vehicle exhaust are quiet a matter of concern. Thus, to control the emissions from CNG engines, the major advances are under development of and oxidation is one of them in catalytic converter. In literature, the catalysts such as noble and non-noble metals have been reported for separate oxidation of CO and CH4.. Experimentally, it was found that non-noble metal catalysts are preferred due to its low cost, good thermal stability, and molding tractability. In literature, several articles have been published for CO and CH4 oxidation but no review paper is still available. Thus, the present review provides a comprehensive overview of separate as well as simultaneous CO and CH4 oxidation reactions for CNG vehicular emission control.

High engine efficiency, comparably low pollutant emissions, and advantageous carbon dioxide emissions make lean-burn natural gas engines an attractive alternative compared to conventional diesel or gasoline engines. However, incomplete combustion in natural gas engines results in emission of small amounts of methane, which has a strong global warming potential and consequently makes an efficient exhaust gas aftertreatment system imperative. Palladium-based catalysts are considered as most effective in low temperature methane conversion, but they suffer from inhibition by the combustion product water and from poisoning by sulfur species that are typically present in the gas stream. Rational design of the catalytic converter combined with recent advances in catalyst operation and process control, particularly short rich periods for catalyst regeneration, allow optimism that these hurdles can be overcome. The availability of a durable and highly efficient exhaust gas aftertreatment system can promote the widespread use of lean-burn natural gas engines, which could be a key step towards reducing mankind’s carbon footprint.

The article presents the results of research and analysis of vibrations of an on-board power unit developed for a 48V electric light commercial vehicle. Auxiliary power unit consisting of a single-cylinder spark-ignition internal combustion engine driving a three-phase synchronous generator was designed and made as a result of the work of the Student Research Group of Internal Combustion Engines at Cracow University of Technology. On the one hand, the auxiliary power unit makes it possible to increase a range of the vehicle with electric propulsion, on the other hand, the operation of a single-cylinder engine on its board negatively affects the comfort of passengers. The presented work was undertaken in order to quantify the impact of an operation of the range extender on the electric vehicle body vibrations and to evaluate the effectiveness of the used vibration-damping elements of the power unit. The carried out experiments indicated the most beneficial configuration of the damping elements. It was also found that the use of the muffler with a catalytic converter enabling exhaust gas aftertreatment increased the range extender vibrations in the high engine speed range and generator load, which was not the case with the factory exhaust system. In the final part of the work, the possibilities of limiting the vibrations generated by the single-cylinder engine used in the project were also indicated.

The behavior of a three-way catalytic converter (TWC) to treat the exhaust from a natural-gas fueled engine in fuel dithering conditions was evaluated by numerical simulation. A validated comprehensive and thermodynamically consistent surface reaction mechanism was utilized to model the natural gas engine exhaust conversion in the TWC at dithering conditions. The mechanism was implemented in a tank-in-series model to study the TWC behavior while air to fuel ratio was cyclically varied (dithering conditions). The simulation results were evaluated by comparison with data collected from a TWC operated at dithering conditions. The microkinetic reaction model predicted the post catalyst total hydrocarbon (THC), NO and CO concentrations well when 5 reaction steps out of 115 elementary steps were modified. Both simulations and experiments showed that TWC window widened in the dithering conditions, particularly dithering yielded improved NO conversion as compared to steady state operation at higher air to fuel ratios. Simulations showed that this was due to a higher number of surface vacancies with dithering that improved NO adsorption and surface reaction. Both dithering parameter including amplitude and frequency was modeled and the results indicated there is an optimal dithering amplitude to achieve lower exhaust emission, larger dithering amplitude decreased the THC conversion because the air fuel ratio shifted to the fuel rich side. Simulations indicated that the dithering frequency did not noticeably impact the exhaust conversion simply because the transition time is relative short.

The huge amount of fly ash produced in the coal industry has caused environmental problems. This research presents the performance of catalytic converters manufactured from coal fly ash for the reduction of gas emissions of a motor vehicle. At idle engine speed and 0.1 MPa air pressure, the presence of activated fly ash as a catalytic converter could reduce the emissions of hydrocarbons (HC) and carbon monoxide (CO) up to 48 and 45%, respectively. The increase in the length of catalytic converter could further decrease the emissions of HC and CO. By increasing the engine speed, the emissions decreased with or without catalytic converter. The optimum air pressure was obtained at 0.1 MPa. The minimum emissions of HC and CO were observed at the engine speed of 2000 rpm, catalyst length of 9 cm and air pressure of 0.1 MPa with the value of 1260 and 8510 ppm, respectively. Therefore, the utilization of fly ash as catalytic converter in the exhaust system motor vehicles can minimize several environmental problems such as fly ash waste and gas emission. Keywords: Catalytic converter, Coal fly ash, Motor vehicle, Gas emission, HC, CO

Based on the analysis of a model tube-type membrane reformer for the production of high-purity hydrogen from natural gas, a satisfactory quantitative correlation of the values of the main technological parameters at an operating temperature of 600°С was established, especially for the mode with purging by steam.

Catalytic converters in vehicles reduce emissions while the use of platinum group metals (PGMs) in them have negative health impacts both in the PGMs mining stage and at the end-of-life PGM recycling stage. This study was conducted to weigh the production-recycling phase impacts and the use phase benefits of a three-way honeycomb catalytic converter by using the disability adjusted life year (DALY) indicator over its cradle-to-cradle life cycle. We have combined the environmental life cycle assessment (LCA) approach with a method to account the workplace impact on human health, which may be adopted in social LCA. In general, a catalytic converter causes more loss of lives (11 days) then it saves (4.5 days) under the egalitarian value perspectives for the baseline production scenario with 160,000 km functional life. Contrary to that, under the same scenario and service life, the catalytic converter saves lives (5.5 days and approx. 6 days for the hierarchist and individualist perspectives, respectively) than it causes loss (about 1 day and 0.6 days for the hierarchist and individualist perspectives, respectively). The geographical hotspot analysis reveals that, while the catalytic converter save lives in Sweden where it is used; it causes more loss of lives elsewhere in the world, particularly in South Africa and Russia. Overall, the DALY varies between 0.62 days and 11.3 days, mainly due to differences in value perspectives. The study showed that increased use of recycled platinum group metals, extended functional life of the catalytic converter may alter the health balance of the product system. This human health-focused cradle to cradle life cycle case study identified methodological issues that need further attention, like development of occupational DALY characterization factors (CFs) for the countries involved in the production of three-way ceramic honeycomb catalytic converter, and emission DALY CFs for PGEs during the use phase of catalytic converter. From scenario analysis, it is observed that, the rise of electric vehicles may drastically alter the social lives lost impacts of catalytic converter.

Diffuser plates in exhaust system manifolds are designed to provide uniform flow pattern within the manifold for maximum utilization of the catalytic converter substrate during high-temperature applications. In this paper, failure analysis of a diffuser which survived only 20% duration of a manifold crack test and various design optimization studies of the diffuser plate using computer-aided engineering (CAE) analyses are presented. During the manifold crack test, the failure occurred at the inner and outer periphery of the diffuser. Metallurgical failure analysis coupled with CAE thermal fatigue analysis of the component concluded that thermal fatigue was the root cause of the failure. The new recommended robust design showed considerable improvement in the thermal durability of the diffuser plate assembly.

As countries around the globe adapt more stringent emissions standards set by Real Driving Emissions (RDE) legislation, mathematical models are becoming ever more widely used as plant models for devising vehicle control strategies. It is important for the model to run on Hardware-in-Loop (HIL) and engine control unit (ECU) systems which have significantly less computational power and memory than modern personal computers. Washcoat diffusion limitations play a very important role in the efficient design of a catalytic converter. Numerical solution of aftertreatment models that include diffusion-reaction equations in the washcoat are computationally demanding. There are several simplified approaches proposed in the literature for the solution of diffusion-reaction equations in the washcoat to avoid the computational demand of the full numerical solution. In this paper, we use the recently proposed asymptotic solution and compare the results with that of the full numerical solution for the following aftertreatment reactor models with both single- and dual-layer washcoat configurations for the practical range of operating conditions; three-way catalyst (TWC), diesel oxidation catalyst (DOC), Selective Catalytic Reduction (SCR), and ammonia slip catalyst (ASC). These reactor models are constructed using published kinetic mechanisms and represent the global kinetics mechanisms (including non-linear reaction orders and inhibition functions) commonly used in the aftertreatment modeling community. We also discuss the importance of adaptive mesh, quasi-steady state assumption, and occurrence of concentration jumps in the simulation of aftertreatment reactors.

N2O emission from automobile has been regulated by the United States Environment Protection Agency due to its higher global warming potential compared to CO2. Responding to this, an instrument for fast sensing of ultra-low concentration of N2O from automobile has become an urgent need. In this study, an instrument based on the quantum cascade laser spectroscopy has been developed and applied for certification testing of ultra-low N2O in automobile exhaust. The pulsed quantum cascade laser can emit coherent lights in the mid-infrared region where N2O shows strong absorption and better control of wavelength. Therefore, a very low detection limit can be achieved and interference of co-existing gases can be avoided using a super fine resolution of the mid-infrared spectrum. The US Code of Federal Regulations Parts 1065/1066 allows measuring N2O from sample storage bags, from a continuous dilute stream or a raw exhaust stream. Typically, batch (bag) sampling has better accuracy and repeatability, but continuous sampling is more efficient in terms of test cell running time and provides test-mode emissions. In this study, the quantum cascade laser analyzer has been applied to investigate correlations between bag sampling and continuous dilute exhaust sampling using a fleet of vehicles with a wide range of N2O emission levels all meeting United States Environment Protection Agency emission standards. Very good correlation between these two sampling methods was observed for the majority of tests conducted and in best case the difference was less than ±1%. The direct injection gasoline vehicle emits higher N2O than conventional port injection gasoline vehicles. The quantum cascade laser analyzer has been successfully applied for United States Environment Protection Agency N2O certification test.

Diesel engines have high efficiency, reliability and durability together with their low operating cost. These important features make them to be widely used in the transportation, automotive, agricultural application and industrial sector. These wide fields of usage lead to the increasing requirements of petroleum derived fuel and going for depletion of petroleum fuel shortly. Hence, it is essential to go for an alternate fuel to diesel and effective control of the various pollutants emitted by the diesel engines. The major pollutants emitted by the diesel engines are unburned hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NO x ), particulate matter (PM), sulphur oxides (SO x ) and lead. These pollutants can cause health problems to human beings and will have an impact on the environment such as climate change, global warming, acid rain, ozone depletion and photo chemical smog. Therefore, the researchers are intended to find out the viable substitute alternate fuel for diesel and control of pollutants from compression ignition (CI) engines. The biodiesel can be used as alternate for diesel, which is a non-fossil fuel, easily available and cheaper. The main drawbacks of biodiesel operated CI engine are reduced performance and increased NO x emission. In order to improve the performance and to reduce exhaust emissions, suitable methods have to be incorporated. Hence, in the present review a detailed study has been carried out with the operating parameters and catalytic converter in biodiesel operated engine, so that its performance can be improved and exhaust emissions were reduced.

Catalytic converters are employed in the automotive and chemical reactor application for reduction and oxidation of toxic by-products produced during the burning of fuels. Every industrial Nation is striving to achieve the stringent pollution norms for environment and safety. It has propelled the need to develop a simulated model of catalytic converter before being put in to action. This paper focusses on the history of development of the catalytic converter and the modifications taken place during the recent years. In earlier development ceramic and metallic monolith were used for making the substrate for catalytic convertor. In recent past, metallic foams were successfully tested for suitability as the alternative for the conventional substrate materials. An insight in to the pressure pattern, flow characteristics and the heat transfer capability of the catalytic converter shows that metallic foams have better heating ability which is convenient for cold starting of engines and improved heat transfer

An All Power Labs PP20 gasifier generation set (Berkeley, Calif.) was tested to evaluate its suitability for powering biomass conversion technologies (BCT) at remote forest operations sites. Feedstock of the species tanoak (), coast redwood (), and Douglas fir () were tested at moisture contents of 15% and 25% (wet basis). The PP20 was connected to a load bank with five different load profiles designed to simulate possible BCT loads. Two parameters of power quality, voltage variability, and frequency deviation, were determined to be within acceptable limits. The unit also successfully powered a remote biochar operation in Branscomb, California. Emissions of the PP20, when compared to diesel generator regulations, would meet non-methane hydrocarbons (NMHC) and NOX requirements but exceed the CO emissions limits by a factor of ten. The CO emissions could be reduced by adding a catalytic converter. The results indicate that it is possible to use a PP20 unit to provide electric power for the highly variable loads of a BCT system. Keywords: Bioenergy, Biomass conversion technology, Gasification, Renewable energy.

Emissions from motorcycles are well known to be a serious cause of environmental pollution. One of the most effective ways to reduce the emissions during cold start of the motorcycle engine is using electrically heated catalytic converters (EHC). In this study, a kinetic model has been developed by using CFD methods to investigate the effects of using EHC on CO emission from motorcycle engines. Apart from three different heating temperatures (600, 800 and 1000 K), the other studied parameters included the heating position (the inlet and the mid-section of the catalyst converter) and heating duration (20, 25 and 35 s). Results showed that using the heater at the inlet of the catalytic converter is more effective than when it is in mid-section and the converter has a higher reaction performance. Moreover, the results indicated that the minimum heating temperature which required the converter to reach the light-off point is 450 K. In addition, the results revealed that when the heaters were turned on prior to cold starting the engine for duration of 35 s, the higher CO conversion occurs.

In the refining and petrochemical industrial sector, large amounts of energy are used, so using the concept of exergy allows a rational use of this resource. In the different exergy and exergoeconomics studies applied in petrochemical plants, parameters of interest have been determined to evaluate the thermal efficiency, the potential for process improvement, the irreversibilities produced by the interaction between the components of the system and the operation of each one, and the energy costs associated with each of these irreversibilities. This paper presents an advanced exergy analysis and an exergy-economic analysis applied to a nitric acid production plant with an installed capacity of 350 metric tons per day, whose operating principle is based on the Ostwald method, and both the behavior of endogenous exergy destruction and the behavior of exogenous, avoidable and unavoidable exergy destruction are studied, exogenous, avoidable and unavoidable exergy destruction and the associated exergy costs in each of the heat transfer equipment and reactive equipment that make up the plant, about the cooling temperature in the intermediate stages of the compression train are studied using a mathematical model. The chemical reactions involved in the production process are the points of interest in the research of this work. Some of the results show that 54 % of the total exergy destruction can be recovered by intervening in the components. On the other hand, in the Catalytic Converter (CONV), it is convenient to consider the investment costs to reduce the exergy destruction costs. Similarly, in the Tail Gas Heater (TGH), it is beneficial to reduce the total investment to improve the process economics. On the other hand, the cost of exergy destruction of the plant resulted in 770.77 USD/h. In addition, it could be determined that the interactions between the components significantly affect the investment costs.

On-board measurements of unit emissions of CO, HC, NO x and CO 2 were conducted on a sample of 17 private cars with different fuels, dual gasoline and LPG, single gasoline and diesel. The 298 tests have shown the effect of LPG injection technology on unit emissions and allowed to compare emissions to Artemis European model. Except for NOx, sequential multipoint injection LPG kit, without catalyst installed is the most efficient for all other pollutants. Particular test results on a subsample of LPG vehicles have shown that LPG fuel alone cannot compete with catalyzed gasoline and diesel vehicles. The advantages of LPG are quickly lost facing the high development of either gasoline or diesel engine technology and catalytic converter. LPG performance seems to be lower under real driving conditions than expected on chassis dynamometer.

Stereo Particle Image Velocimetry (SPIV) is used to measure the highly turbulent flow in the upstream region of the catalytic converter for a four stroke IC engine. These experiments are conducted for a motorized engine to investigate the feasibility of using SPIV for exhaust flow measurements in a firing IC engine in our future research. The results obtained here can also be used for validation of the CFD models. The measured flow is highly three dimensional, non-uniform with large magnitudes of turbulence indicating recirculating flow structures. These structures show signatures of jet flows coming out of the exhaust valves at all exhaust crank angles. The triangular shape and location for the end face of each exhaust runner pipe, the length and geometry of the runners also affect the flow mixing process upstream of the catalytic converter contributing to the complexity of this flow. Although majority of the exhaust flow passes through the catalytic converter, some will recirculate due to impingement of the exhaust jets on the surface of the catalyst.

The rapid increase of the number of motor vehicles, especially motorcycles, makes serious problem caused by the pollution from gas emission of fossil fuel combustion. The problems related to human health and the erosion on ozone layer is credited to its gas emission. Several dangerous and toxic gasses such as Hydrocarbon (HC), Carbon Monoxide (CO), and Nitrogen Oxide (NOx), Sulphur Dioxide (SO2), and Lead (Pb) are emitted during IC engine operation.To manage those dangerous gasses, catalytic converter which converts the gasses into more eco-friendly CO2H2O and N2 may be employed. In this research, a specially designed catalytic converter made from brass (CuZn) wire in the form of spider web pattern was fitted into exhaust system of a standard motorcycle. The performance of the converter for several engine rotation speeds was examined by measuring CO and HC of exhaust by using Gas Analyzer.By comparing the exhaust of a standard exhaust system and modified exhaust system (fitted with converter), it can be concluded that the converter was able to decrease the exhaust emission gas. For HC content, the percentage of decrease was as much as 36,88 % for converter fitted exhaust system compared to 61.12% for standard one. For CO content, the decrease percentage was 19.90% compared to 80.10% for standard one.

International audience; Because of more and more stringent vehicle emission standards, Hybrid Electric Vehicles (HEV) are developed. Gasoline-HEV are equipped with 3-Way Catalytic Converter (3WCC). So the energy management systems of such vehicles , which must reduce not only fuel consumption, but also vehicle pollutant emissions, have to consider the 3WCC heating. A pollutant constrained energy management strategy is presented. A 3WCC multi-0D model is built from physical equations, with a good complexity-performances compromise. An off-line optimal strategy allows the joint minimization of pollution and fuel consumption with only one parameter to tune, while considering all the standardized pollutant emissions. This strategy reduces significantly the vehicle emissions for a minor fuel consumption increase and leads to define 3WCC smart heating. Thus an on-line smart heating strategy is implemented in a HyHIL (Hybrid Hardware In the Loop) test bench, reducing the pollutant emissions of the classical charge sustaining strategy by 30 % for CO and 10 % for N O X .

The heat of exhaust gases in the device of vehicle converter patented by us gets accumulated in the course of vehicle movement by the heat-accumulation substance and transmitted in the process of its crystallization (300 - 4500С) to a converter for increasing its efficiency during short-time stops. The purpose of investigation was the development of mathematic model of catalysis process in the mode of heat rejection (“discharge”) of phase change storage device and substantiation of high efficiency of cleaning from harmful substances and possibility of device arrangement in the engine compartment of a bus instead of noise suppressor using calculation method proceeding from experimental data of converter operation in the city cycle. The relevancy of mathematic model and expected results have been proven at KamAZ-740.10 (8ЧН 12/12) engine tested at KAMAZ OJSC.