Automotive air pollution : issues and options for developing countries

Air pollution constitutes an ominous threat to human health and welfare. Its adverse effects are pervasive and may be disaggregated at three levels: (a) local, confined to urban and industrial centers; (b) regional, pertaining to transboundary transport of pollutants; and (c) global, related to build up of greenhouse gases. These effects have been observed globally but the characteristics and scale of the air pollution problem in developing countries are not known; nor has the problem been researched and evaluated to the same extent as in industrialized countries. Air pollution, however, can no longer be regarded as a local or a regional issue as it has global repercussions in terms of the greenhouse effect and depletion of the ozone layer. This paper discusses the contribution of motorized land transport to air pollution problems, with special reference to developing countries. It assesses the adverse effects of air pollution from transport sources, primarily motor vehicles, and reviews possible approaches to bring about improvements. The paper identifies key issues and research needs related to land transport and air pollution in developing countriesTransport and Environment,Environmental Economics&Policies,Montreal Protocol,Energy and Environment,Roads&Highways

Cost implications of various Euro 4 and 5 after treatment solutions for heavy duty diesel vehicles

This study is firstly a short review of the types of exhaust systems predicted for Euro 4 (2005) and Euro 5 (2008), particularly focussed on the effects of combined NOx (nitrogen oxides) and PM (particulate matter) aftertreatment systems. Secondly, it explores in detail the implications of using a liquid secondary water-based fuel of urea on board heavy duty diesel vehicles in Europe as a basis for NOx reduction via selective catalytic reduction (SCR). Some of the main points that become apparent when using integrated SCR systems are: the potential costs of increased urea production in Europe (including possible fuel taxation), refuelling issues, secondary fuel cost, logistics of urea supply, and cost of implementation of the urea fuel delivery method. From the original equipment manufacturers view, the hardware cost will be increased substantially when compared to current silencer systems. From the vehicle owner’s point of view, the possibility of large running cost increases is not desired, and the system solution cost and its benefits must ultimately be acceptable. This paper will attempt to put the life-time costs of various systems within perspective in order to assess the feasibility of implementing selective catalytic reduction systems (SCR) Europe wide for the near future

Performance evaluation of exhaust aftertreatment devices used for emissions control on diesel engines employed in underground coal mines

This study was initiated to assist the WV Diesel Equipment Commission in its promulgation of initial rules, requirements, and standards governing the operation of diesel-powered equipment in underground coal mines. Four different engines and various exhaust after treatment devices that represent current levels of in-use technology were selected for performance evaluation. Both eddy-current and water-brake dynamometers were used to load the engines according to an ISO 8-Mode test cycle. Experimental emissions data, sampled from a full-flow dilution tunnel, suggests that particulate traps can reduce the mass emission rates of particulate matter (DPM) by nearly 90%, while reductions in fuel sulfur content (0.04% compared to 0.37% by mass) can reduce DPM mass emissions by as much as 22%. The study concluded that the singular usage of catalytic converters is not recommended for the confined spaces of a mining environment, due to their tendency to enhance particulate matter sulfate production and possibly increase overall exhaust toxicity

Supporting the regeneration process of a diesel particulate filter with the addition of hydrogen and hydrogen/carbon monoxide mixtures: diesel engine aftertreatment system

This thesis was submitted for the degree of Doctor of Philosophy and was awarded by Brunel UniversityThis investigation aims to enhance the regeneration performance of a diesel particulate filter. This is achieved by introducing various chemical components to the regeneration process, which are representative of what can be generated ‘on board’ a vehicle using an exhaust gas fuel reformer. By researching the effects of introducing such components using a periodic injection cycle the aim is to reduce the volume of ‘reformates’ required to assist in proficient diesel particulate filter regeneration. As a result, this study also aims to support future work in the development of exhaust gas fuel reformer design for DPF aftertreatment applications. All experiments were performed using a Ford Puma 2.0 litre diesel engine. A test rig was constructed and installed that featured a mini diesel particulate filter housed within a tubular furnace. Exhaust gas could be sampled directly from the exhaust manifold and fed through the DPF. Exhaust gas measurements were taken both pre and post DPF using a FTIR spectrometer. It was shown that the regeneration process could be supported substantially by the introduction of hydrogen. Similar properties were also demonstrated when introducing a hydrogen-carbon monoxide mixture. The introduction of these species allowed for the regeneration process to be implemented at filter temperatures substantially lower than the passive regeneration temperature. Furthermore, by introducing these simulated reformates using a periodic injection strategy, it was evident that similar benefits to the regeneration process could be attained with significantly less volumes of simulated reformates. In an attempt to effectively utilise the carbon monoxide generated during hydrogen production by an exhaust gas fuel reformer, this study defined an optimised hydrogen/carbon monoxide mixture ratio of 60% (v/v) hydrogen balanced with carbon monoxide. At this optimised mixture ratio, the filter demonstrated the highest regeneration efficiency of all ratios tested. Such data could be utilised in future work in the development of fuel reformer design.Engineering and Physical Science Research Council (Grants EP/F025416/1 and EP/G038007/1)

Characterization of exhaust emissions from catalyzed trap-equipped non-road heavy-duty diesel engines

An emissions and engine performance study was conducted to explore the effects of ultra low sulfur fuels on an off-road, heavy-duty engine retrofitted with catalyzed traps. The study was conducted, on an 8 cylinder, mechanically controlled Caterpillar 3408, rear engine of a Scraper. An in-field transient duty cycle was determined by logging the engine speed and torque using an Electronic Control Unit (ECU) communication adapter on the Scraper. The test fuels included California Air Resources Board (CARB) off-road diesel fuel, Fischer-Tropsch and Emission Control Diesel-1 (ECD1) diesel fuels. The engine was retrofit with two different types of diesel particulate filters (DPF) (Johnson-Matthey CRT and Engelhard DPX). (Abstract shortened by UMI.)

SOOT REMOVAL SYSTEM USING ELECTROMAGNETIC WAVE HEATING FOR VEHICLE EXHAUST AFTER TREATMENT

The electromagnetic soot removal system trap particulate particles from the exhaust gas of diesel engines. The efficiency of the trap is defined by the effectiveness of the trap to filter the particles. Since the new prototype was used, the effectiveness of the soot removal system has not been ascertain. This can be done by laboratory experiment to analyze the electromagnetic soot removal system. The objective of this research focused on analyzed the electromagnetic wave soot removal system regarding gas velocity after soot trap(filter) element at various outlet opening and gas velocity with different soot particle loading in filter element. From the experiment has been done, the finding shown various outlet opening and different soot particle loading in filter element give significant different in gas velocity measured

Simulation of Diesel Particulate Filter regeneration using Lattice Boltzmann method

Lattice Boltzmann Method is a novel approach, which has shown promise in solving a wide variety of fluid flow problems including single and multi-phase flows in complex geometries. Volume elements of the fluid domain are considered to be composed of particles and these particles fall under a velocity distribution function at each grid point. Particles collide with each other under the influence of external forces and the rules of collision are defined so as to be compatible with the Navier-Stokes Equation. In the current work, LBM has been applied to Diesel Particulate filters which is a device used for reducing Particulate Matter emissions from diesel engines. Diesel Particulate Filtering (DPF) technologies as they are collectively known, have a two-step mechanism to them. First is the trapping of the particulate matter and second is the regeneration process, which is essentially the cleaning process applied to get rid of the trapped soot with or without the help of catalytic compounds. The deposited soot is oxidized during this regeneration process. This oxidation of soot has been modeled in the current work using LBM. An artificially created porous microstructure as used by authors in some earlier works has been used to simulate the flow of fluid, which is considered to have a specified mass fraction of soot for different runs of the simulation. The velocity and concentration fields have been modeled with a D2Q9 lattice arrangement and the temperature field with a D2Q4 arrangement. The numerical code is developed using C. Flow over a heated cylinder has been modeled as a benchmark case. The pressure, velocity, temperature and concentration contours for the disordered media are compared with published work