A miniature Portable Emissions Measurement System (PEMS) for real-driving monitoring of motorcycles

Michal Vojtisek-Lom,Martin Pechout,Giorgio Martini,Lubos Dittrich,François Montigny,Massimo Carriero,Fausto Forni,Barouch Giechaskiel,Alessandro A Zardini

doi:10.5194/amt-13-5827-2020

Abstract

Abstract. We present an exploratory study carried out with a new miniature portable emission measurement system (Mini-PEMS) specifically designed at the Technical University of Liberec (CZ) for applications on two-wheeler vehicles owing to its reduced size (45cm×30×20cm) and weight (≈15 kg). It measures the exhaust gas concentrations of hydrocarbons and carbon mono- and dioxide with a nondispersive infrared method and nitrogen mono- and dioxides and oxygen using an electrochemical cell. In addition, the instrument acquires the engine speed, manifold absolute pressure, inlet and exhaust gas temperature, geo-localization, and vehicle speed. The exhaust mass flow rate is calculated from engine and emission data. The Mini-PEMS was validated on three two-wheelers (one moped and two motorcycles) against laboratory-grade instrumentation in the Vehicle Emissions Laboratory of the European Commission in terms of measured concentrations, exhaust flow, fuel consumption, and mass emission of pollutants. The mean absolute deviations of gas concentrations were 8 % for HC, 8 % for CO, 13 % for NOx, and 2 % for CO2, while the mass emissions (which include the exhaust flow determination uncertainty) were 7 % for HC, 7 % for CO, 9 % for NOx, and 5 % for CO2. An agreement of 2 % was achieved between the fuel consumption measured in the laboratory and calculated by the Mini-PEMS. As an application, the instrument was tested on board the vehicles during on-road trips. The emissions measured on the road were consistent among repeated runs, with differences between laboratory and on-road tests much larger than those between the Mini-PEMS and laboratory. We found similar or larger HC and NOx real-driving emissions and larger CO emissions from motorcycles and smaller ones for the moped. Considering its size and weight, the Mini-PEMS proved to be an efficient tool for vehicle monitoring, research and development and could be tested for in-service monitoring applications related to carbon monoxide and nitrogen oxides emissions. A tentative approach to characterize particulate mass and particle number was presented and compared to the existing filter method and nonvolatile particle number protocol.

Highlights

Exhaust emissions from internal combustion engines remain one of the primary sources of air pollution in populated areas and are believed to be responsible in the European Union (EU) for an order of magnitude more premature deaths than traffic accidents (EEA, 2018).Two-wheelers such as mopeds and motorcycles are known to be strong emitters of particulate matter, hydrocarbons, and carbon monoxide, and their contribution to air pollution can be amplified by their mode of use, mainly urban and with cold engine conditions (e.g., Kumar et al, 2011; Platt et al, 2014 and references therein)
The worst single-test deviation was for nitrogen oxides (NOx) in Test 1 (24 %) due to substantial zero drift of the Mini-portable emissions monitoring systems (PEMSs) sensor
We presented an exploratory study aiming at assessing a miniature portable emission measuring system (Mini-PEMS) suitable to be installed on board two-wheelers given its small size and weight

Summary

Introduction

Exhaust emissions from internal combustion engines remain one of the primary sources of air pollution in populated areas and are believed to be responsible in the European Union (EU) for an order of magnitude more premature deaths than traffic accidents (EEA, 2018). Two-wheelers such as mopeds and motorcycles are known to be strong emitters of particulate matter, hydrocarbons, and carbon monoxide, and their contribution to air pollution can be amplified by their mode of use, mainly urban and with cold engine conditions (e.g., Kumar et al, 2011; Platt et al, 2014 and references therein). M. Vojtisek-Lom et al.: A miniature Portable Emissions Measurement System that the term “asymmetric pollution” was introduced to describe the low share of the total vehicle fleet along with the large contribution to air pollution (Platt et al, 2014). The use of alkylated fuels with only trace content of aromatic compounds (< 1 % v/v concentration compared to 29 %– 35 % v/v concentration in standard gasoline) proved to be extremely beneficial in terms of particulate emissions and secondary aerosol formation as demonstrated by Zardini et al (2014)

Objectives

Methods

Results

Conclusion