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uCARe – You can also reduce emissions

Practical tools and guidelines for reducing motor vehicle emissions

The uCARe project was established to reduce the overall pollutant emissions of existing combustion engine vehicles by providing drivers with simple and effective tools to decrease their individual emissions. It also supported those interested in local air quality in selecting feasible intervention strategies that lead to reduced emissions.

The main contribution of the FME CTU in Prague was in real-world emissions measurements using portable measurement systems and in transfering real-world emissions measurement results into practical recommendations.

Effect of driving conditions on nanoparticles from brake wear

With exhaust emissions being reduced, and traffic intensity increasing in many countries, brake wear particles are becoming an important part of total vehicle emissions. While many particles are coarse and settle quickly to the ground, friction brakes also produce nanoparticles. In uCARe, data from brake wear particle measurement were analyzed, and additional tests run at the VSB Technical University of Ostrava, to show how nanoparticles emitted by automobile brakes are affected by driving conditions. A combination of high initial speed and high deceleration rate has resulted in especially high emissions, with one deceleration from 175 to 100 kph at 5 m.s-2, equivalent to a relatively harsh (but not emergency) braking of a speeding car slowed down by a passing bus on a motorway, producing similar quantity of nanoparticles as thousands of km of „ordinary“ driving.

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Citizen science measurements of NO2 concentrations in urban air

Results of nitrogen dioxide (NO2) measurements performed by citizen groups using passive samplers were analyzed both for their correlation with data measured by traditional air pollution monitoring network (aiding in validation of this relatively novel approach) and for their correlation with traffic intensity and factors such as incline and intersections, providing a better idea about high pollution hotspots and about the contribution of the traffic to NO2 concentrations.

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On-road detection of high NOx emitters

[projekty/uCARe/image008.png]Large part of total emissions originates from high emitting vehicles, with many malfunctions being overlooked, sometimes intentionally, and sometimes even intentionally created, like circumventing or removing exhaust gas aftertreatment (catalytic converters and particle filters). Manipulation of SCR systems, reducing over 90 % of NOx emissions from heavy vehicles, by installing „SCR emulators“ is a prime example. To examine the extent of the problem, and to showcase the possibility to quickly identify problematic vehicles, a Czech Customs Office patrol vehicle was equipped for one week with an FTIR analyzer, and used to remotely measure NOx emissions from over 250 trucks traveling on the D1 motorway. The results have been published in Science of the Total Environment

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On-road measurement of emissions of key reactive nitrogen species using a portable FTIR analyzer

projekty/uCARe/image010.pngExhaust aftertreatment devices are highly effective, over 90% on the average, at reducing the emissions of gaseous organic compounds, carbon monoxide, and nitrogen oxides. Yet at the same time, they may produce additional pollutants – nitrogen monoxide may get oxidized to more harmful nitrogen dioxide. Also, nitrous oxide, a potent greenhouse gas, and ammonia, a secondary aerosol precursor, may be formed during NOx reduction. A summary of measurement of key nitrogen compounds, NO, NO2, NH3 and N2O, using an on-board FTIR as a single instrument for all gaseous pollutants, was prepared and is linked below:

https://publications.jrc.ec.europa.eu/repository/bitstream/JRC126978/kj0621173enn.pdf#page=271

Measurement of real-world emissions from diesel locomotives and railcars

Emissions reduction efforts have been primarily targeting light and heavy on-road vehicles (M and N categories). In order to elucidate real-world emissions from other mobile sources, emissions from rail vehicles (one motorized rail car and two diesel locomotives) have been measured during their real-world scheduled passenger line-haul service. This was also done to establish a baseline for emissions reduction efforts.

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Measurement of real-world emissions of mopeds and small motorcycles

In a similar manner, the real driving emissions approach was extended to moped and motorcycles, which are generally difficult to measure on the road, due to limited space for instruments. CTU on-board emissions analyzer, mounted on the motorcycle accelerating through a remote emissions measurement gate, was used as a part of the validation of several remote sensing instruments.

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Low-cost instrumentation for testing presence and integrity of diesel particle filters

[projekty/uCARe/image007.png]Existing smoke opacity tests are often not sensitive enough to detect nanoparticles produced by modern diesel engines. For this reason, the measurement of non-volatile particle number (nvPN) concentrations was proposed as an addition to the periodic vehicle emissions test (and later implemented in Denmark, Germany, Netherlands and Switzerland). The nvPN instruments are, however, rather expensive, with a cost over 10 thousands of EUR at the time. For this reason, a low-cost instrument, less than 100 EUR, has been designed as an alternative. The concept is described in a diploma thesis by Yash Patel:

https://dspace.cvut.cz/bitstream/handle/10467/97133/F2-DP-2021-Patel-Yash-Yash.D.Patel.pdf

Contact:

prof. Michal Vojtíšek, M.S., Ph.D.

Department of Automotive, Combustion Engine and Railway Engineering FME CTU in Prague

E-mail: michal.vojtisek@fs.cvut.cz

Phone: +420 774 262 854