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Abstract and Figures

Many alternative fuel technologies have been studied for the transport sector to increase its sustainability while reducing costs, greenhouse gases (GHG), and air pollution emissions. Nevertheless, conventional diesel is still the predominant fuel for heavy-duty trucks. Road freight transport consumes 25% of the world’s energy and is responsible for emissions with local health impacts and the global greenhouse effect. In this context, this paper reviewed items from 2015 to 2020 to analyze the technologies available for the road freight transport regarding pollutant and GHG emissions. Results are presented in two parts: first quantitatively, quantitative data was extracted from reviewed papers and statistically treated and, second, qualitatively through a comparative chart, which shows the impact on air pollutants from the use of a different type of fuels. In general, papers are mostly concerned with particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC) emissions due to its impact on public health, with a low number of papers covering GHG emissions. The trade-off between different fuels and how this process can impact emissions, sometimes increasing or decreasing specific pollutants, is discussed. According to the analyzed papers, the main characteristics that affect the pollutant emissions are, in general, the fuel oxygen content and the combustion chamber temperature.
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REVIEW ARTICLE
Alternative fuel technologies emissions for road heavy-duty
trucks: a review
Ana Carolina Rodrigues Teixeira
1
&Pedro Gerber Machado
2
&Flávia Mendes de Almeida Collaço
3
&
Dominique Mouette
3
Received: 29 May 2020 /Accepted: 25 February 2021
#The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2021
Abstract
Many alternative fuel technologies have been studied for the transport sector to increase its sustainability while reducing costs,
greenhouse gases (GHG), and air pollution emissions. Nevertheless, conventional diesel is still the predominant fuel for heavy-
duty trucks. Road freight transport consumes 25% of the worlds energy and is responsible for emissions with local health
impacts and the global greenhouse effect. In this context, this paper reviewed items from 2015 to 2020 to analyze the technologies
available for the road freight transport regarding pollutant and GHG emissions. Results are presented in two parts: first quanti-
tatively, quantitative data was extracted from reviewed papers and statistically treated and, second, qualitatively through a
comparative chart, which shows the impact on air pollutants from the use of a different type of fuels. In general, papers are
mostly concerned with particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons (HC) emis-
sions due to its impact on public health, with a low number of papers covering GHG emissions. The trade-off between different
fuels and how this process can impact emissions, sometimes increasing or decreasing specificpollutants, is discussed. According
to the analyzed papers, the main characteristics that affect the pollutant emissions are, in general, the fuel oxygen content and the
combustion chamber temperature.
Keywords Heavy-duty vehicles .Internal combustion engines .Alternative fuel .Transport sector .Emissions .Air pollution
Introduction
Road freight transport contributes significantly to the global
economy and directly affects national economiesefficiency
(Nowakowska-grunt et al. 2019). Fossil fuels drive the sector,
and diesel oil is still the most used energy carrier in heavy-
duty trucks (Qu et al. 2016). Some advantages of this type of
transport compared with others (rail, air, water) include low
cost, reduced transit times, and increase reliability, while dis-
advantages cover traffic congestion and air pollutants (Lee
and Yoo 2016). According to IEA (2019), CO
2
emissions
generated by trucks and buses have increased 2.2% yearly.
The combination of using fossil sources and high distances
traveled annually contribute to the increase of air pollution and
GHG emissions, directly impacting human health and the
environment.
To reduce emissions to meet standards, improve efficiency,
and find cheaper ways to transport goods, the heavy-duty trans-
port profile has been changing over the years (Alam et al. 2015;
Qu et al. 2016). To attain the Sustainable Development
Scenarios (SDS) and the Nationally Determined Contributions
Responsible editor: Philippe Garrigues
*Ana Carolina Rodrigues Teixeira
acrt88@hotmail.com
Pedro Gerber Machado
ppgerber@gmail.com
Flávia Mendes de Almeida Collaço
flavia.collaco@usp.br
Dominique Mouette
dominiquem@usp.br
1
Institute of Energy and Environment, University of São Paulo,
Avenida Professor Luciano Gualberto, 1289, São
Paulo, SP 05508-010, Brazil
2
Chemical Engineering Department, Imperial College London, South
Kensington, London SW7 2BU, UK
3
School of Arts, Science, and Humanities, University of São Paulo,
Rua Arlindo Béttio, São Paulo, SP 1000, Brazil
https://doi.org/10.1007/s11356-021-13219-8
/ Published online: 8 March 2021
Environmental Science and Pollution Research (2021) 28:20954–20969
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
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Vehicular emissions (VE) are among the major sources of airborne fine particulate matter (PM 2.5 ) in urban atmospheres, which adversely impact the environment and public health. Receptor models are widely used for estimating PM 2.5 source contributions from VE (PM vehicle ), but often give inconsistent results due to different modelling principles and assumptions. During December 2015–May 2017, we collected nine-months of hourly organic carbon (OC) and elemental carbon (EC) data, as well as 24-h PM 2.5 speciation data including major species and organic tracers on select days from an ad hoc roadside site in Hong Kong. The weekday vs. holiday and diurnal variations of EC tracked closely with those of traffic flow volume, indicating EC as a reliable tracer for PM vehicle in this area. We applied multiple approaches to estimate the PM vehicle , including the EC-tracer method with the hourly OC-EC data, and chemical mass balance (CMB) and positive matrix factorization (PMF) analyses with the filter-based speciation data. Considering source profile variability, CMB gave the lowest PM vehicle estimate among the three approaches, possibly due to the degradation of organic markers (i.e., hopanes). The PM vehicle derived from the EC-tracer method and PMF were comparable, accounting for ~12% (3.4–4.0 μg/m ³ ) of PM 2.5 averaged across 20 samples in both approaches, but a larger sample size is needed for a more robust PMF solution. The monthly PM vehicle derived from the EC-tracer method was in the range of 3.2–6.6 μg/m ³ . The continuous measurement reveals a decreasing trend in PM vehicle throughout the entire sampling period, indicating the effectiveness of a recent vehicle control measures implemented by the Government in phasing out pre-Euro IV diesel commercial vehicles. This work implies that hourly OC-EC monitoring at strategically located spots is an effective way of monitoring vehicle control measures. It provides reasonable estimate of PM vehicle through comparing with other more sophisticated receptor models.
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Freight movement is a significant and growing contributor to transportation emissions globally. Modal shifts in freight, that is, moving freight from a higher emission mode to one associated with lower emissions, are discussed as a strategy to reduce emissions of criteria pollutants and greenhouse gases (GHGs). However, there is limited knowledge of the magnitude of potential benefits and their impacts on human health. The overall goal of this study is to identify and characterize the potential of modal shifts in freight transport for mitigating air pollutant emissions, air pollutant concentrations, population exposure to air pollutants, and health impacts. The analysis was conducted in the Canadian context, with a focus on land-based freight such as trucks, trains, and pipelines, as well as marine shipping for inland and coastal waters. A structured review of the existing literature database, and a critical assessment of the findings was conducted, using a weight-of-evidence approach. The assessment took into consideration potential local and regional variables for Canada. The results indicated that there is limited evidence that road-to-rail, road-to-marine, and rail-to-marine modal shifts could reduce pollutant and GHG emissions. There was insufficient evidence on modal shifts involving the pipeline mode, and on the air quality, population exposure, and health impacts related to any modal shift. Several research gaps remain, which must be addressed establish the emissions, air quality, and health impacts of freight modal shifts.