Fugitive Emissions from Mobile Sources—Experimental Analysis in Buses Regulated by the Euro 5 Standard

Abstract

Fugitive emissions are unintentionally produced by pipeline leakage and evaporation in industrial processes and contribute 5% of Global Greenhouse Gas emissions (GHG). Frictional wear and thermal fatigue in vehicle exhaust pipe couplings and joints can cause leaks that are not visible and difficult to quantify. It is therefore essential to trace and document these sources. In this work, an experimental survey was conducted on buses in accordance with Regulation (EC) N° 715/2007 of the European Parliament. Statistical methods by means of a priori analysis aided by G∗Power 3.1 software was used to define the required sample. Three random sample groups were stratified and fugitive gases were encased and piped into a bronze tube 5 mm in diameter and 500 mm in length. A Horiba PG-300 analyzer was used to analyze the samples using chemiluminescence and infrared methods. The results proved the existence of fugitive emissions in all samples analyzed with variations of (3.000–27.500 ppm) among the samples for CO2, (6.0–138.5 ppm) and (2.0–5.0 ppm) for CO and NOx, respectively. Statistical analysis showed that engine mileage had no significant influence on NOx emissions, while CO and CO2 emissions increased with mileage. Analysis using Response Surface Methodology (RSM) indicated a trend of increasing concentrations of CO2 and CO for both explanatory variables, mileage and usage time.