The demand for fossil fuel in the transport sector is constantly increasing and transportation is ranked amongst the highest greenhouse emitting sectors globally. Today, tackling CO 2 emissions from road transport a widely discussed topic and constitutes a milestone towards reaching a sustainable, carbon neutral economy. This challenge is being described in various initiatives adopted in the European Union and other parts of the world. So far several measures have been proposed and adopted for reversing the increasing greenhouse gas emissions trends. This paper attempts an overview of the existing policy framework in various countries focusing on European Union. In addition, the main technical measures proposed and promoted in this direction are presented and evaluated with respect to their greenhouse reduction potential. Special attention is paid to emerging technologies, such as hybrid vehicles and biofuels. The main factors differentiating the officially reported CO 2 emissions from actual real life emissions are discussed and a brief evaluation of the current European policy is presented.
Pressure drop modelling is a subject of special interest for the design and control of diesel particulate filters. Based on previous experience, an improved pressure drop model is presented. Special emphasis is given on the soot permeability properties and its dependence on temperature and pressure. With the assumption of uniform wall flow distribution throughout the channel length, it is possible to derive an analytic expression for pressure drop calculation. The main difference with previously proposed analytic expressions lies in the inclusion of gas density dependence on local pressure, which necessitates an iterative calculation procedure. The importance of this improvement is illustrated parametrically. The new model is validated against experimental data on an engine bench, using a double filter configuration to ensure constant filter soot loading throughout the test.
The present study explores net carbon-neutral road transport options in the EU27 in 2050 from a well-to-wheel (WtW) perspective. To this aim, three scenarios were developed regarding the evolution of the road-vehicle fleet composition, the degree of electrification of powertrains, and technical measures such as vehicle efficiency improvements, transport flow, and transport volumes. The fleet scenarios are further combined with four scenarios deploying different mixes of alternative fuels in 2050, including electricity, e-fuels, liquid/gaseous advanced biofuels and remaining fossil fuel components. Two different electricity production pathways are considered, as well. The Joint Research Centre's DIONE model was used for the scenario calculations. From a tank-to-wheel (TtW) perspective, each scenario reduces energy consumption, mainly due to powertrain electrification, with EU27 TtW road vehicle energy consumption in 2050 ranging from roughly 650 to 1650 TWh, which is 20% to 53% of that of 2019. Well-to-tank (WtT) energy consumption is around 20% of TtW energy, ranging around 110-160TWh depending on the fuel scenario, for the most strongly electrified fleet scenario with optimistic assumptions on measures to improve vehicle efficiency, transport flow and transport volumes and renewable electricity production. If a moderately electrified fleet is propelled with e-fuels, even when assuming fully renewable electricity and optimistic measures, the WtT energy increases to 130% of the TtW energy, or 1300 TWh (or 2150 TWh with pessimistic measures). The results show that fleet electrification is the strongest lever for WtW transport energy consumption reduction among the options considered. Other efficiency measures contribute significantly to energy savings, but their benefit decreases with increasing fleet electrification. The production pathways of fuels considered make a substantial difference for WtW fleet energy requirement if the fleet is moderately electrified, in which case e-fuels require significant amounts of additional renewable electricity. But fuel production pathways become irrelevant from an energetic point of view under very ambitious electrification scenarios as their volumes become marginal.
This paper presents a new concept of a partial flow sampling system (PFSS), involving a two-stage diluter which operates on the principle of underpressure, while exhaust is sampled through a capillary. Due to the low flowrate through the capillary, the diluter may be sampling from a freely exhausting tailpipe and is not prone to pressure variations in the exhaust line. In addition, the PFSS operates at constant pressure conditions even upstream of diesel particle filters that increase the backpressure in the tailpipe. As a result, the PFSS offers a constant dilution ratio (DR) over any engine or vehicle operation condition. This study presents the diluter concept and a straightforward model developed to calculate the DR, depending on the dilution air flowrate and the diluter underpressure. The model is validated using CO2 as a trace gas, and very good agreement is demonstrated between the calculated and the measured DR values. Following validation, the PFSS is combined with aerosol measurement instruments to measure the exhaust particle concentration of a diesel engine operating at different steady-state modes. For demonstrating the stability of the DR and applicability of the PFSS, measurements are conducted with both heavy duty and light duty diesel exhaust gases. Future applications of this device include gas and particle exhaust measurements both in laboratory environments and on-board vehicles.
The paper presents the main elements of a project entitled ICT-Emissions that aims at developing a novel methodology to evaluate the impact of ICT-related measures on mobility, vehicle energy consumption and CO2 emissions of vehicle fleets at the local scale, in order to promote the wider application of the most appropriate ICT measures. The proposed methodology combines traffic and emission modelling at micro and macro scales. These will be linked with interfaces and submodules which will be specifically designed and developed. A number of sources are available to the consortium to obtain the necessary input data. Also, experimental campaigns are offered to fill in gaps of information in traffic and emission patterns. The application of the methodology will be demonstrated using commercially available software. However, the methodology is developed in such a way as to enable its implementation by a variety of emission and traffic models. Particular emphasis is given to (a) the correct estimation of driver behaviour, as a result of traffic-related ICT measures, (b) the coverage of a large number of current vehicle technologies, including ICT systems, and (c) near future technologies such as hybrid, plug-in hybrids, and electric vehicles. The innovative combination of traffic, driver, and emission models produces a versatile toolbox that can simulate the impact on energy and CO2 of infrastructure measures (traffic management, dynamic traffic signs, etc.), driver assistance systems and ecosolutions (speed/cruise control, start/stop systems, etc.) or a combination of measures (cooperative systems).The methodology is validated by application in the Turin area and its capacity is further demonstrated by application in real world conditions in Madrid and Rome.
