Sorin Ilie

Recovery of Precious Metals from Catalytic Converters of Automobiles by Hydrometallurgical Solid-Liquid Extraction Processes

Today, among the basic requirements to be fulfilled by an automobile, those relating to environmental protection and recyclability are of great importance. This paper aims to present a new technological solution to recover rare metals - Platinum, Palladium and Rhodium - from automotive used catalysts, based on hydrometallurgical method of solid-liquid extraction. Following the theoretical and experimental researches, were established the technological sequences which must be carried for recovering precious metals from used automotive catalysts, in the pilot phase. The proposed technology has been applied for a quantity of 10 kg of used automotive catalysts of ceramic monolithic type, at the end of the recovery process and selective separation, resulting the following recovery efficiencies: 95 % for Platinum, 95 % for Palladium and 92 % for Rhodium. Finally, there were highlighted the main advantages of hydrometallurgical processes: versatility, economicity, high efficiencies and relatively low costs.

PERFORMANCE EVALUATION OF COMPLEX INTERSECTIONS BY MICRO-SIMULATION

The increase of motorization index, the spatial redistribution of land use functions, the jobs crisis, the degradation of level of service provided by rail mode occurred in Romania in the last two decades have led to increased demand for road transport mode. In the large cities and their suburban areas the phenomenon of congestion occurs, as a consequence of the fact that weren’t major interventions in order to increase the transport capacity. An essential stage in the transport planning process is the diagnosis of current situation, because based on its results is possible to propose solutions for improving traffic conditions. To analyze complex intersections or groups of junctions, the measured traffic volumes are insufficient and traffic micro-simulation is required. Micro-simulation takes into account the physical characteristics of the vehicle, the traffic rules and psychological behavior of the driver, achieving a stochastic and dynamic representation of each vehicle in the traffic flow. In this paper is made an analysis of performances offered by the road intersection located in the suburban area of Pitesti City, situated at the junction of three main networks (a highway, two national roads and the urban network), by applying the micro-simulation of traffic flows.

Accelerated testing of an optimized closing system for automotive fuel tank

Taking into account the legal prescriptions which are in force and the new regulatory requirements that will be mandatory to implement in the near future regarding testing characteristics of automotive fuel tanks, resulted the necessity to develop a new testing methodology which allows to estimate the behaviour of the closing system of automotive fuel tank over a long period of time (10-15 years). Thus, were designed and conducted accelerated tests under extreme assembling and testing conditions (high values for initial tightening torques, extreme values of temperature and pressure). In this paper are presented two of durability tests which were performed on an optimized closing system of fuel tank: (i) the test of exposure to temperature with cyclical variation and (ii) the test of continuous exposure to elevated temperature. In these experimental tests have been used main components of the closing system manufactured of two materials variants, both based on the polyoxymethylene, material that provides higher mechanical stiffness and strength in a wide temperature range, as well as showing increased resistance to the action of chemical agents and fuels. The tested sample included a total of 16 optimized locking systems, 8 of each of 2 versions of material. Over deploying the experiments were determined various parameters such as: the initial tightening torque, the tightening torque at different time points during measurements, the residual tightening torque, defects occurred in the system components (fissures, cracks, ruptures), the sealing conditions of system at the beginning and at the end of test. Based on obtained data were plotted the time evolution diagrams of considered parameter (the residual tightening torque of the system consisting of locking nut and threaded ring), in different temperature conditions, becoming possible to make pertinent assessments on the choice between the two types of materials. By conducting these tests and interpreting the obtained results, it can be created a clear picture of the capacity of closing system of fuel tank to fulfil the functional requirements following the exposure to values of testing parameters significantly above the values that may appear throughout the entire service life of the vehicle. The proposed accelerated testing method shows the main advantage of simulation in a limited time all the situations which may be encountered in a much longer period of time, namely the service life of the vehicle.

The Estimation of CO2 Emission from Road Vehicles by Traffic Macro-Simulation

Remarkable growth of population and mobility needs in the last century, especially in urban areas, is associated with air pollution. Reducing emissions of greenhouse gases from road vehicles is the main concern about the sustainability of road transport. The main factor derived from anthropogenic activities that contribute to increased greenhouse effect is CO2. This is the main product resulting from the combustion process that occurs during operation of thermal self-propelled vehicle. In this paperwork is estimated the volume of CO2 from road vehicles depending on speed. The case study is conducted for a medium sized city in Romania, Bistrita. The average speed of the vehicles on urban road network, the structure and volume of traffic flow were determined by transport modeling macro-simulation of road traffic using PTV-VISUM specialized software. The variation curves of CO2 volume according to the average speed used in this application has been validated for the structure of national fleet in the document Romania—Technical assistance for the elaboration of the General Transport Master Plan. These were determined according to CORINAIR methodology agreed by European Environment Agency, for the following categories: cars, light trucks, medium trucks and heavy trucks. Applying the methodology of calculation of CO2 based on average travel speed integrated with traffic modeling (knowing the average travel speed and the number of vehicles of existing categories on each segment of road network) allows the estimation of the volume of CO2 from mobile sources (vehicles) on any road network segments analyzed.