Emission Measurement of Buses Fueled with Biodiesel Blends during On-Road Testing

Séverine Cassiers,François Idczak,Kris Martens,Hervé Jeanmart,Rafael Maes,François Boveroux,Benjamin Bergmans,Christophe Martin,Francesco Contino

doi:10.3390/en13205267

Abstract

Increasing the biodiesel content of diesel fuels is encouraged because of its reduced carbon footprint. Pure rapeseed methyl ester (RME)and used cooking oil methyl ester (UCOME) are characterised by well-to-tank greenhouse gas (GHG) reductions of 54% and 88% compared to pure B0 petrodiesel, respectively. Captive fleets such as public transport buses could benefit from these GHG reductions by increasing the biodiesel content of their fuel because they have a consequent yearly fuel consumption. The aim of this paper is to compare on-road tailpipe emissions of a diesel bus when increasing the biodiesel concentration in the fuel. The tests were carried out on a standard city bus belonging to the Euro V EEV emission standard that was equipped with a portable emission measurement system measuring NO, NO2, PN, CO and CO2 at the tailpipe. The bus followed the SORT which is representative of urban bus driving. The heavy urban on-road measurements indicated increased NOx emissions (24–26%), decreased PN emissions (43–45%) and slightly decreasing CO emissions for B30 RME and UCOME compared to B7. A measurement uncertainty analysis showed that the CO emissions were less reliable. Similar conclusions were drawn for the easy urban on-road bus emission measurements with smaller differences between B7 and B30 RME and UCOME.

Highlights

Biodiesel has a positive impact on CO2 emissions with an estimated overall greenhouse gas (GHG)reduction of 30% to 90% compared to diesel depending on the type of biodiesel [1]
During the heavy urban standardised on-road test cycle (SORT) 1 cycle, increased nitrogen oxide emissions are measured when the bus is fueled with B30 rapeseed methyl ester (RME) and B30 used cooking oil methyl ester (UCOME) compared to B7
Concerning particle number emissions, a decrease is measured during the heavy urban SORT 1 cycle when the bus is fueled with B30 RME and B30 UCOME compared to B7

Summary

Introduction

Reduction of 30% to 90% compared to diesel depending on the type of biodiesel [1]. Increasing the volume concentration of biodiesel would reduce the carbon footprint of the fuel used by vehicles. Captive fleets such as long-haul trucks and transit buses would in particular benefit from large scale GHG reductions when using a fuel with higher biodiesel concentration. These fleets are characterised by predictable and recurrent driving and refuelling patterns involving

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