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Vehicle emissions, arising from incomplete fuel combustion and reactions between N2 and O2 leading to NOX, have detrimental effects on human health and environment quality. Engine exhaust contains a variety of regulated components, such as hydrocarbons, CO, nitrogen oxides (NOX), and particulate matter (PM). Government environmental agencies have been continuously establishing regulations for automobile manufacturers to reduce these emissions. Lean-burn engines operate with an excess of oxygen, which makes the reduction of NOX, challenging, with a coincident challenge for diesel engines being PM. Diesel particulate filters have been successfully employed to reduce PM. NOX storage and reduction (NSR) catalysts and selective catalytic reduction (SCR) catalysts are two promising technologies used to mitigate NOX emissions. A diesel oxidation catalyst (DOC) is usually placed upstream of these to reduce hydrocarbons and CO emissions and oxidize NO to NO2, which leads to improved performance over these catalysts. In this study, the performance of DOCs and NSR catalysts, individually and in series, has been investigated as a function of temperature, gas composition, catalyst length, and catalyst configuration. The catalytic oxidation of CO, hydrocarbons, and NO, both individually and in mixtures with NO2, was investigated over a monolith-supported DOC. The data clearly show mutual inhibition effects between these species. Addition of each gas to the inlet gas mixture caused an increase in the light-off temperatures of the other species, mainly due to site adsorption competition. CO was less affected by other species because its light-off temperatures began prior to those of NOX and other hydrocarbons, and it is likely the primary surface species poisoning the active sites at low temperature. Hydrogen production via hydrocarbon steam reforming and water gas shift reactions was also investigated over a DOC during steady-state and cycling conditions (to mimic NSR catalyst operation) along the catalyst length. C3H6 and dodecane steam reforming started at 375 and 450°C, respectively, whereas the water gas shift reaction started at 225°C, and proceeded further than hydrocarbon steam reforming in terms of H2 production. It should be mentioned that H2 production via the hydrocarbon steam reforming and water gas shift reactions during cycling experiments, was higher than that observed during steady-state experiments. According to temperature programmed oxidation experiments performed after steam reforming, the better performance during cyclic operation is because less coke was deposited compared to that with steady-state experiments. Experiments were also performed over a NSR catalyst. The evaluations included testing the performance as a function of NOX source, NO or NO2, testing different regeneration protocols, and evaluating different reducing agents (hydrocarbons, H2, or CO). For NO and NO2 as the NOX source, the trapping and reduction performance was better when NO2 was used at all operating temperatures except 300ºC, likely due to high NO oxidation activity and rapid trapping of NO2 at 300ºC. Numerous reasons were provided to explain the improved performance with NO2 at other tested temperatures. The foremost reason though, is treating the monolith as an integral reactor. With NO2 as the NOX source, NO2 can be readily trapped at the very inlet and along the catalyst length, resulting in a higher trapping amount. Along the same concept, the released NOX from the inlet of the catalyst has more residence time and contact with downstream Pt sites, but more importantly more interaction between reductant and stored NOX. In the second set of experiments, different regeneration protocols were used. Different regeneration times, 4, 8 and 16 seconds with 4, 2, and 1% H2 as the reductant amounts, and constant lean times were evaluated. The data clearly show an improvement with longer regeneration times in both NOX trapping and overall reduction performance at all temperatures except 500°C, where the more significant NOX release resulted in an overall decrease in NOX conversion with increasing regeneration time. The improved performance at the lower temperatures is due to more extensive nitrate/nitrite decomposition with longer regeneration times, thus leading to more extensive surface cleaning. The performance of the NSR catalyst was also investigated using hydrocarbons, H2, or CO as reducing agents. H2 was found the best at T ≤ 250°C, where the decreased performance with CO and hydrocarbons was due to Pt site poisoning at 200°C and as a result of slow kinetics at 250°C. CO and hydrocarbons, however, proved to regenerate the catalyst as efficiently as H2 at T ≥ 300°C. Hydrogen production via steam reforming experiments can not explain the improved performance with hydrocarbons, since propylene steam reforming occurred at 375°C, with only a small amount of H2 generated, and dodecane or m-xylene reforming did not occur below 450°C. TPR data show that propylene started to activate as low as 217°C and the complete reduction of NO by propylene was achieved at 287°C. For surface chemisorbed NOX species, propylene was observed to reduce these species at T > 200°C, with high rates by 264°C, with this activity eventually leading to comparable performance with either CO or H2 at similar temperatures during NOX cycling experiments. The performance of two different hybrid DOC+NSR systems was also investigated. In the first configuration, a DOC and NSR catalyst were placed in series while in the other configuration, the DOC and NSR catalysts were divided into two equal volumes and placed in series (DOC + NSR + DOC + NSR). Overall, the data show an increase in the NOX performance with the split configuration at all temperatures tested, with small changes at 200°C due to poisoning effects of Pt and Ba sites by CO and hydrocarbons being significant. The improved performance with the split configuration was related to further NO oxidation occurring over the 2nd DOC, more H2 formed from steam reforming and WGS reactions, and reduced inhibition of the WGS reaction by hydrocarbons.

Vehicle emissions, arising from incomplete fuel combustion and reactions between N2 and O2 leading to NOX, have detrimental effects on human health and environment quality. Engine exhaust contains a variety of regulated components, such as hydrocarbons, CO, nitrogen oxides (NOX), and particulate matter (PM). Government environmental agencies have been continuously establishing regulations for automobile manufacturers to reduce these emissions. Lean-burn engines operate with an excess of oxygen, which makes the reduction of NOX, challenging, with a coincident challenge for diesel engines being PM. Diesel particulate filters have been successfully employed to reduce PM. NOX storage and reduction (NSR) catalysts and selective catalytic reduction (SCR) catalysts are two promising technologies used to mitigate NOX emissions. A diesel oxidation catalyst (DOC) is usually placed upstream of these to reduce hydrocarbons and CO emissions and oxidize NO to NO2, which leads to improved performance over these catalysts. In this study, the performance of DOCs and NSR catalysts, individually and in series, has been investigated as a function of temperature, gas composition, catalyst length, and catalyst configuration. The catalytic oxidation of CO, hydrocarbons, and NO, both individually and in mixtures with NO2, was investigated over a monolith-supported DOC. The data clearly show mutual inhibition effects between these species. Addition of each gas to the inlet gas mixture caused an increase in the light-off temperatures of the other species, mainly due to site adsorption competition. CO was less affected by other species because its light-off temperatures began prior to those of NOX and other hydrocarbons, and it is likely the primary surface species poisoning the active sites at low temperature. Hydrogen production via hydrocarbon steam reforming and water gas shift reactions was also investigated over a DOC during steady-state and cycling conditions (to mimic NSR catalyst operation) along the catalyst length. C3H6 and dodecane steam reforming started at 375 and 450°C, respectively, whereas the water gas shift reaction started at 225°C, and proceeded further than hydrocarbon steam reforming in terms of H2 production. It should be mentioned that H2 production via the hydrocarbon steam reforming and water gas shift reactions during cycling experiments, was higher than that observed during steady-state experiments. According to temperature programmed oxidation experiments performed after steam reforming, the better performance during cyclic operation is because less coke was deposited compared to that with steady-state experiments. Experiments were also performed over a NSR catalyst. The evaluations included testing the performance as a function of NOX source, NO or NO2, testing different regeneration protocols, and evaluating different reducing agents (hydrocarbons, H2, or CO). For NO and NO2 as the NOX source, the trapping and reduction performance was better when NO2 was used at all operating temperatures except 300ºC, likely due to high NO oxidation activity and rapid trapping of NO2 at 300ºC. Numerous reasons were provided to explain the improved performance with NO2 at other tested temperatures. The foremost reason though, is treating the monolith as an integral reactor. With NO2 as the NOX source, NO2 can be readily trapped at the very inlet and along the catalyst length, resulting in a higher trapping amount. Along the same concept, the released NOX from the inlet of the catalyst has more residence time and contact with downstream Pt sites, but more importantly more interaction between reductant and stored NOX. In the second set of experiments, different regeneration protocols were used. Different regeneration times, 4, 8 and 16 seconds with 4, 2, and 1% H2 as the reductant amounts, and constant lean times were evaluated. The data clearly show an improvement with longer regeneration times in both NOX trapping and overall reduction performance at all temperatures except 500°C, where the more significant NOX release resulted in an overall decrease in NOX conversion with increasing regeneration time. The improved performance at the lower temperatures is due to more extensive nitrate/nitrite decomposition with longer regeneration times, thus leading to more extensive surface cleaning. The performance of the NSR catalyst was also investigated using hydrocarbons, H2, or CO as reducing agents. H2 was found the best at T ≤ 250°C, where the decreased performance with CO and hydrocarbons was due to Pt site poisoning at 200°C and as a result of slow kinetics at 250°C. CO and hydrocarbons, however, proved to regenerate the catalyst as efficiently as H2 at T ≥ 300°C. Hydrogen production via steam reforming experiments can not explain the improved performance with hydrocarbons, since propylene steam reforming occurred at 375°C, with only a small amount of H2 generated, and dodecane or m-xylene reforming did not occur below 450°C. TPR data show that propylene started to activate as low as 217°C and the complete reduction of NO by propylene was achieved at 287°C. For surface chemisorbed NOX species, propylene was observed to reduce these species at T > 200°C, with high rates by 264°C, with this activity eventually leading to comparable performance with either CO or H2 at similar temperatures during NOX cycling experiments. The performance of two different hybrid DOC+NSR systems was also investigated. In the first configuration, a DOC and NSR catalyst were placed in series while in the other configuration, the DOC and NSR catalysts were divided into two equal volumes and placed in series (DOC + NSR + DOC + NSR). Overall, the data show an increase in the NOX performance with the split configuration at all temperatures tested, with small changes at 200°C due to poisoning effects of Pt and Ba sites by CO and hydrocarbons being significant. The improved performance with the split configuration was related to further NO oxidation occurring over the 2nd DOC, more H2 formed from steam reforming and WGS reactions, and reduced inhibition of the WGS reaction by hydrocarbons.

The subject of this Master Thesis is construction of hydrogen generator for automotive industry. The objective is to design system which is able to produce required amount of gas. The master thesis includes basic analysis of situation, mathematical equations of electrolytic process and procedure of mechanical design according required power of generator. The next part is design of power control system of hydrogen generator based on informations from automobile. The last part describes power supply of whole system with electric energy. The output of the Master Thesis is the whole design of hydrogen generator including sensor system and control system. The thesis also includes suggestions for next improvements and research.

No description available.

Aleksandro Stulginskio Universitete, Transporto ir Jėgos Mašinų Inžinerijos Institute, atliktais tyrimais nustatyta, kad vieno cilindro tiesioginio įpurškimo dyzelinis variklis (,,Oruva“ F1L511) maitinamas pagerintu, 0,08; 0,12; 0,20vol% cetaninį skaičių (CS) didinančiu priedu, rapsų aliejumi (RA), gali efektyviai veikti ir išskirti mažesnę, kai kurių emisijos komponentų dalį. Dyzelinio variklio išvystytas didžiausias efektyvusis slėgis siekė 0,57MPa, varikliui veikiant 2000 min-1 sūkių dažniu. Variklio minimaliosios lyginamosios efektyviosios degalų sąnaudos sumažėjo nuo 272g/kWh iki 268g/kWh tai yra 1,5% panaudojus 0,12vol% cetaninį skaičių didinantį priedą rapsų aliejuje. Deginių dūmingumas sumažėjo 45% vidutinės (pe=0,4MPa) ir 40% didžiausios (pe=0,57MPa) apkrovos srityje atitinkamai panaudojus 0,12vol% ir 0,20vol% cetaninį skaičių didinantį priedą rapsų aliejuje. Bandymų metu didžiausias ƞe=0,364 variklio efektyvusis naudingumo koeficientas buvo pasiektas variklį maitinant 0,12vol% cetaninį skaičių didinančiu priedu apdorotu rapsų aliejumi ir jam išvysčius 5,3 kW efektyviąją galią. Tačiau mažesnės ir didesnės variklio išvystomos efektyviosios galios srityse aukštesnis variklio efektyvusis naudingumas buvo bazinio rapsų aliejaus naudojimo atveju. / Studies conducted at Aleksandas Stulginskis University (ASU) of Transport and Power Machinery Engineering Institute showed that a single-cylinder, air-cooled, direct-injection diesel engine (" Oruva " F1L511 ) can be with rapeseed oil treated with 0.08vol%, 0.12vol% and 0.20vol% the cetane number (CN) improving agent. Diesel engine developed the maximum effective pressure of 0.57MPa when running at 2000 rpm speed. Using of 0.12vol% of the cetane number improving agent (2-ethylheksyl-nitrate) to rapeseed oil the brake specific fuel consumption reduced in the range 272 g/kWh to 268 g/kWh, i.e. 1.5% when running at moderate (pe=0.38MPa) load and 2000 rpm speed. As a result of 0.12vol% the smoke opacity decreased by 45% at moderate (pe=0.4MPa) and 40% at maximum (pe=0.57MPa) load. During the tests, the highest ƞe=0.364 effective efficiency engine was when running on rapeseed oil treated with 0.12vol% cetane improving agent developed at the power output of 5.3 kW.

Este trabalho de pesquisa visa estudar o processo de formação das emissões gasosas num motor de combustão interna movido à álcool e analisar os fatores que contribuem para o controle dessas emissões em níveis estabelecidos pela legislação. Especial atenção foi dada à aplicação de conversores catalíticos platina/paládio como auxiliar no processo de controle das emissões gasosas automotivas. Foram realizados ensaios dinanométricos de um motor de combustão interna para analisar as emissões e o controle destas, em condições operacionais, em função da razão ar-combustível, ponto de ignição e rotação. O conversor catalítico contribuiu para redução de mais de 80% das emissões gasosas danosas à saúde, quando o motor operava em condições estequiométricas. Observou-se a necessidade de desenvolver o sistema de admissão e descarga do motor para receber o catalisador sem que este cause redução considerável à queda da eficiência volumétrica do motor. / This work of research aim analyzes process of formation of gas emissions in alcohol internal combustion engines and analyses factors that contribute to control those emissions in level established by legislation. Special attention was faced application of catalytic converters platin/palladium with auxiliary in the process of control emissions gas automotives. Assays dynamometric were realized of to analyses emission and control them, in conditions operation ales, in function of air-fuel ratio, point of ignition and rotation the catalytic converters contribute to reduction more of 80% of emissions gas that cause damage health, when observed that necessity of develop system of admission and exhaust of engines to receive catalysts out that provocate reduction considerable decrease of efficiency volumetric of engines.

Este trabalho de pesquisa visa estudar o processo de formação das emissões gasosas num motor de combustão interna movido à álcool e analisar os fatores que contribuem para o controle dessas emissões em níveis estabelecidos pela legislação. Especial atenção foi dada à aplicação de conversores catalíticos platina/paládio como auxiliar no processo de controle das emissões gasosas automotivas. Foram realizados ensaios dinanométricos de um motor de combustão interna para analisar as emissões e o controle destas, em condições operacionais, em função da razão ar-combustível, ponto de ignição e rotação. O conversor catalítico contribuiu para redução de mais de 80% das emissões gasosas danosas à saúde, quando o motor operava em condições estequiométricas. Observou-se a necessidade de desenvolver o sistema de admissão e descarga do motor para receber o catalisador sem que este cause redução considerável à queda da eficiência volumétrica do motor. / This work of research aim analyzes process of formation of gas emissions in alcohol internal combustion engines and analyses factors that contribute to control those emissions in level established by legislation. Special attention was faced application of catalytic converters platin/palladium with auxiliary in the process of control emissions gas automotives. Assays dynamometric were realized of to analyses emission and control them, in conditions operation ales, in function of air-fuel ratio, point of ignition and rotation the catalytic converters contribute to reduction more of 80% of emissions gas that cause damage health, when observed that necessity of develop system of admission and exhaust of engines to receive catalysts out that provocate reduction considerable decrease of efficiency volumetric of engines.

Detta är en studie med syfte att visa vid vilka driftsförhållanden fartyget M/T Ramonas framdriftsmotor driver fartyget som mest bränsleeffektivt och på så sätt även med minst miljöpåverkan genom avgasutsläpp (Havsmiljöinstitutet, 2017). Dessa två driftsförhållande är lastad samt olastad kondition. Fartyget har under studien körts med så kallat combinator mode och har haft sin strömförsörjning via en axelgenerator. Resultatet baseras på 12 veckors datainsamling.Efter att all data samlats in och uträkningar analyserats, har ett resultat per kondition kunnat presenteras med hjälp utav figurer. Den slutsats som kunde dras var att, vid lastad kondition driver framdriftsmotorn fartyget som mest effektivt vid en belastning på 46 till 48 procent och en hastighet på 10.5 knop. Dock finns en felmarginal då tester inte tilläts vid lägre belastningar på framdriftsmotorn vid tiden för studien. Slutsatsen som drogs för den olastade konditionen var att framdriftsmotorn driver fartyget som mest bränsleeffektivt vid en belastning på 34 till 38 procent och en hastighet på 8.3 knop. / This is a study aimed at showing the operating conditions at which the M/T Ramonas propulsion engine is operated most fuel efficient and thus also with the least environmental impact through exhaust emissions (Havsmiljöinstitutet, 2017). These two operating conditions are loaded and unloaded condition. During the study, the ship has been run in so-called combinator mode and has had its electricity generated via a shaft generator. The result is based on 12 weeks of data collection. After all the data has been collected and calculations has been analyzed, a result per condition has been presented using figures. The conclusion that could be drawn was that, at loaded condition, the propulsion engine is driven most fuel efficiently at a load of 46 to 48 percent and at a speed of 10.5 knots. However, there is a margin of error as tests were not allowed at lower loads on the propulsion engine at the time of the study. The conclusion reached for the unloaded condition was that the propulsion engine is driven most fuel-efficient at a load of 34 to 38 percent and at a speed of 8.3 knots.

Human activities have increased the concentration of CO2 into the atmosphere, thus it has caused global warming. Construction equipment are semi-stationary machines and spend at least 30% of its life time during idling. The majority of the construction equipment is diesel powered and emits toxic emission into the environment. In this work, the idling will be investigated through adopting several statistical regressions models to quantify the fuel consumption of construction equipment during idling. The regression models which are studied in this work: Multivariate Linear Regression (ML-R), Support Vector Machine Regression (SVM-R), Gaussian Process regression (GP-R), Artificial Neural Network (ANN), Partial Least Square Regression (PLS-R) and Principal Components Regression (PC-R). Findings show that pre-processing has a significant impact on the goodness of the prediction of the explanatory data analysis in this field. Moreover, through mean centering and application of the max-min scaling feature, the accuracy of models increased remarkably. ANN and GP-R had the highest accuracy (99%), PLS-R was the third accurate model (98% accuracy), ML-R was the fourth-best model (97% accuracy), SVM-R was the fifth-best (73% accuracy) and the lowest accuracy was recorded for PC-R (83% accuracy). The second part of this project estimated the CO2 emission based on the fuel used and by adopting the NONROAD2008 model.  Keywords: