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Automobile Exhaust Emmision Control- A review

Manav Rachna International University-Sunny Bhatia
  • Technical Paper
  • 2019-28-2382
To be published on 2019-11-21 by SAE International in United States
Since the 20th century increase in the number of cars in the major cities is been a point of concern because of the toxic gasses being emitted from the engine of an automobile. These gasses are polluting the atmosphere and degrading the air to breathe. The main gasses responsible for the degradation of air quality are carbon monoxide, hydrocarbon and oxides of nitrogen. There is a necessity to find ways to reduce the pollution emitted into the atmosphere from the automobile. The source of emission is either evaporation from fuel tank or carburetor which is easy to be dealt with or harmful gasses due to improper combustion which is a concern for the environment. The two ways to reduce these emissions are, modification in the engine to minimize the production of harmful gases and to treat the harmful gasses emitted from the engine before blowing it into the atmosphere from the exhaust. Catalysts help to break harmful gasses into smaller compounds that are environment-friendly. The catalysts used are Rhodium Palladium and platinum, these make a…

Design, Development and Analysis of Mullite Catalytic Converter for CI Engines

Kongu Engineering College-Selvakumar Pandiaraj, Dhamotharan Subbaiyan, Tamilvanan Ayyasamy, Sathishkumar Nagarajan
  • Technical Paper
  • 2019-28-0017
To be published on 2019-10-11 by SAE International in United States
Emissions of Hydrocarbon (HC), Carbon Monoxide (CO) and Oxides of Nitrogen (NOx) are the largest concerns for fossil fuel driven automotive vehicles. Catalytic converter is an important component in the selective catalytic reduction process. It oxidizes harmful CO and HC emission to CO2 and H2O in the exhaust system and thus the emission is controlled. Different kinds of problems are associated with noble metal based catalytic converter. A catalytic converter with a new catalyst for compression ignition engine is considered in this study. The catalytic converter is designed and developed with a new catalyst. Due to better durable characteristics and poison resistant nature, non-noble metal based material limestone (Mullite) is selected as a catalyst for catalytic convertor and the emission characteristics are studied on four stroke single cylinder CI engine by using Mullite based catalytic converter. The results are compared without catalytic converter in the same engine. In the design stage, the back pressure analysis is performed on perforated Mullite plate with ANSYS software. After arriving satisfactory results, the design is taken for development. The…

Study of NOx Reduction efficiency in NSR and NSR-SCR Combined Systems

Vellore Institute of Technology-Saravanan Supramani, Ramesh Kumar Chidambaram
  • Technical Paper
  • 2019-28-0087
To be published on 2019-10-11 by SAE International in United States
The present study was carried out to analyze the catalytic action of K2O-Al2O3 in NOx storage and Reduction (NSR) monolith catalyst in addition to Fe2O3-TiO2 in Selective Catalytic Reduction (SCR) monolith catalyst to determine their NOx reduction capabilities with respect to engine exhaust gas temperature. To accomplish this task monolith ceramic bricks were coated with K2O-Al2O3 (NSR) and Fe2O3-TiO2 (SCR) catalyst and were placed in different configurations inside the catalytic chamber. Several trials were attempted to get the optimal operating temperature that has a maximum NOx removal efficiency when successively connecting single NSR catalyst and the combined NSR–SCR double bed arrangement. Finest operation of the single NSR monolith was attained at 320 ºC, which showed NOx removal rate of 74% while, the double NSR–SCR configuration permitted the SCR catalyst storing ammonia to respond with NOx leaving the NSR in gaining higher NOx removal rates. The SCR reaction between ammonia which leaves from NSR, later adsorbed by SCR and the NO that is not reacted in NSR which enters SCR resulted in a total NOx removal…

Optimization of the Exhaust Aftertreatment System of a Heavy Duty Engine by means of Variable Valve Timing

Technische Universität Braunschweig-Marius Betz, Peter Eilts
  • Technical Paper
  • 2019-24-0143
To be published on 2019-09-09 by SAE International in United States
In view of the current political debate, it can be assumed that the nitrogen oxide limits for commercial vehicles will be further reduced. This is also demonstrated by the currently voluntary certification of the CARB Optional Low NOX legislation, which requires nitrogen oxide emissions of 0.027 g / kWh. This corresponds to a reduction of 93% compared to the current EU VI standard. Therefore, the optimization of EAT systems represents an essential research focus for future commercial vehicle applications. One way to optimize the EAT system may be the usage of variable valve actuation. Existing investigations show an exhaust gas temperature increase with Miller timing, but the authors conclude that it cannot accelerate the heating process. With regard to the effects on the exhaust aftertreatment system and the resulting tailpipe emissions, only improved HC and CO oxidation could be identified so far. In addition, a potential for improved NOX reduction is expected in the exhaust gas temperature increase. Therefore, investigations are carried out at the Institute of Internal Combustion Engines of the Technical University of…

Diesel Vehicle with Ultra-low NOx Emissions on the Road

AECC-Joachim Demuynck, Cecile Favre, Dirk Bosteels
IAV-Frank Bunar, Joachim Spitta, Andreas Kuhrt
  • Technical Paper
  • 2019-24-0145
To be published on 2019-09-09 by SAE International in United States
The paper discusses the technical approach to meet Euro 6d Real-Driving Emissions (RDE) requirements and beyond, with a particular focus on reducing diesel NOx emissions in urban driving situations. Novel technology aspects of the diesel powertrain are an RDE-optimized catalyst system layout to improve both low- and high-load DeNOx performance and a 48V P0-hybrid system. A key element of the powertrain concept is the advanced model based DeNOx control strategy. The optimized exhaust aftertreatment layout combines lean NOx Trap (LNT) and Selective Catalytic Reduction (SCR) technologies. For maximum low load DeNOx performance, the close-coupled SCR, consisting of an additional slice upstream of an SCR coated on filter, is assisted by an LNT. High load conditions are covered by a 2-stage SCR system with twin AdBlue® dosing. The P0 48V electric motor supports the NOx control in addition to ensuring good driving performance and fuel efficiency. A smart and advanced control strategy is implemented to ensure optimal interaction between all components. The first part of the proposed paper provides a brief summary of Euro 6d and…

Analysis and Modeling of NOx Reduction Based on the Reactivity of Cu Active Sites and Brønsted Acid Sites in a Cu-Chabazite SCR Catalyst

Waseda Univ-Yoshihisa Tsukamoto, Takao Fukuma, Jin Kusaka
  • Technical Paper
  • 2019-24-0150
To be published on 2019-09-09 by SAE International in United States
In this study, the NOx purification reactivity of a Cu-chabazite SCR catalyst was analyzed over a wide temperature range based on the NH3-SCR mechanism considering Cu redox reactions and reactions on a Brønsted acid site. It was revealed that the De-NOx reactions on the active site of Cu proceeded in different paths at lower and higher temperatures. This means that the rate-limiting step of SCR reactions was changed as each temperature. The reaction rate of NOx purification on a Cu site less than 200 °C was determined by the reaction rate of oxidation of Cu sites. On the other hand, the NH3 adsorption on Cu sites played a dominant role in NOx purification at temperature range higher than 300°C. Moreover, it was also observed that the Cu reaction site took different states at low and high temperatures during the NOx purification and was estimated that the valence state of a Cu site was changed as the temperature increased. In order to analyze the reaction on a Brønsted acid site of chabazite structure, analysis using an…

Experimental and Numerical Analysis of Latest Generation Diesel Aftertreatment Systems

Cornaglia SpA-Alessio Tarabocchia
Politecnico di Torino-Francesco Sapio, Federico Millo, Debora Fino, Alessandro Monteverde, Enrico Sartoretti
  • Technical Paper
  • 2019-24-0142
To be published on 2019-09-09 by SAE International in United States
A comprehensive experimental and numerical analysis of two state-of-the-art diesel AfterTreatment Systems (ATS) for automotive applications is presented in this work. Both systems, designed to fulfill Euro 6 emissions regulations standards, consist of a closed-coupled Diesel Oxidation Catalyst (DOC) followed by a Selective Catalytic Reduction (SCR) catalyst coated on a Diesel Particulate Filter (DPF), also known as SCR on Filter (SCRoF). While the two systems feature the same Urea Water Solution (UWS) injector, major differences could be observed in the UWS mixing device, which is placed upstream of the SCRoF, whose design represents a crucial challenge due to the severe flow uniformity and compact packaging requirements. First, both the ATS were experimentally characterized to determine the UWS spray characteristics (i.e. liquid penetration, droplets size) and to evaluate the NOx conversion efficiency under steady state flow conditions, representative of type-approval operating conditions. The experiments highlighted relevant differences in terms of NOx conversion efficiency between the two ATS, especially at low temperature operation. In order to highlight the root causes of these differences, a numerical analysis was…

Multidimensional Modeling of SCR Systems via the Lattice Boltzmann Method

University of Rome Niccolò Cusano-Giovanni Di Ilio
University of Rome Tor Vergata-Vesselin Krastev, Gino Bella, Giacomo Falcucci
  • Technical Paper
  • 2019-24-0048
To be published on 2019-09-09 by SAE International in United States
In this paper, we deploy a novel, multidimensional approach to simulate SCR reactors across physical scales. For the first time, a full 3D Lattice Boltzmann (LB) solver is developed, able to accurately capture the fluid dynamic phenomena taking place inside SCR reactors, as well as the catalytic conversion of NOx. The influence of engine load on exhaust gas mass flow rate and catalytic converter activity is taken into account. The proposed approach is computationally light and the results prove the reliability and versatility of the LB Method for the simulation of the complex phenomena that take place inside the after-treatment devices.

Chemical and Physical Characteristics of Organic Particulate Matter from Exhaust After-Treatment System of Euro 6 Diesel Engine Operating at Full Load

FPT Motorenforschung AG-Wolfgang Gstrein, Konstantinos Priftis
Istituto Motori-CNR-Ezio Mancaruso, Bianca Maria Vaglieco
  • Technical Paper
  • 2019-24-0053
To be published on 2019-09-09 by SAE International in United States
The current legislation does not take into account the limitation of sub 23 nm particles from engine. Nevertheless, the Common Rail Diesel engine emits a large number of nanoparticle, solid and volatiles, that are very dangerous for human health. In this contest, the challenge of the “dieper EU project” is to apply advanced technologies for exhaust after-treatment to existing diesel engines and to optimize the characteristics of a new generation of engines with regards to emissions, fuel consumption and drivability.Aim of the present paper is to provide useful information for the development of the after-treatment system that will have to fulfill Euro6 further steps. In order to characterize the chemical and physical nature of Particulate Matter emitted from Euro 6b Medium Duty diesel engine, the pollutants were collected and analyzed: from engine-out, downstream of the particulate filter (DPF), and at the exit of a selective catalytic reactor (SCR). An array of chemical, physical and spectroscopic techniques (Gas chromatography coupled with mass spectrometry (GC-MS), mobility analyzer, UV-visible absorption and fluorescence spectroscopy) was applied for characterizing the…

JCB prepared to meet EU Stage V emissions

SAE Truck & Off-Highway Engineering: August 2019

Dan Gilkes
  • Magazine Article
  • 19TOFHP08_09
Published 2019-08-01 by SAE International in United States

JCB is preparing to offer Stage V compliant engines across its equipment lines, with updates to its own engine range and changes to supplier models. Group director of engines Alan Tolley said that the company has preferred to tackle emissions within the combustion system, rather than simply adding aftertreatment to the exhaust system; however, for Stage V, diesel particulate filters (DPFs) and selective catalytic reduction (SCR) will become necessary.

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