title: Climate and health relevant emissions from in-use Indian three-wheelers fueled by natural gas and gasoline.
abstract: Auto-rickshaws in India use different fuels and engine technologies, with varying emissions and implications for air quality and climate change. Chassis dynamometer emission testing was conducted on 30 in-use auto-rickshaws to quantify the impact of switching from gasoline to compressed natural gas (CNG) in spark-ignition engines. Thirteen test vehicles had two-stroke CNG engines (CNG-2S) and 17 had four-stroke CNG engines (CNG-4S), of which 11 were dual-fuel and operable on a back-up gasoline (petrol) system (PET-4S). Fuel-based emission factors were determined for gaseous pollutants (CO(2), CH(4), NO(X), THC, and CO) and fine particulate matter (PM(2.5)). Intervehicle variability was high, and for most pollutants there was no significant difference (95% confidence level) between "old" (1998-2001) and "new" (2007-2009) age-groups within a given fuel-technology class. Mean fuel-based PM(2.5) emission factor (mean (95% confidence interval)) for CNG-2S (14.2 g kg(-1) (6.2-26.7)) was almost 30 times higher than for CNG-4S (0.5 g kg(-1) (0.3-0.9)) and 12 times higher than for PET-4S (1.2 g kg(-1) (0.8-1.7)). Global warming commitment associated with emissions from CNG-2S was more than twice that from CNG-4S or PET-4S, due mostly to CH(4) emissions. Comprehensive measurements and data should drive policy interventions rather than assumptions about the impacts of clean fuels.
authors.affiliation: Institute for Resources, Environment and Sustainability, University of British Columbia, 2202 Main Mall, Vancouver, BC V6T 1Z4, Canada.
authors.forename: Conor C O
authors.initials: CC
authors.lastname: Reynolds
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Grieshop
authors.forename: Milind
authors.initials: M
authors.lastname: Kandlikar
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D057231:Climate Change; D003247:Conservation of Natural Resources; D004784:Environmental Monitoring; D005579:Fossil Fuels / Q000032:analysis / Q000706:statistics & numerical data*; D005742:Gasoline / Q000032:analysis / Q000706:statistics & numerical data; D057232:Global Warming; D006801:Humans; D007194:India; D018986:Motor Vehicles / Q000706:statistics & numerical data*; D052638:Particulate Matter / Q000032:analysis; D001335:Vehicle Emissions / Q000032:analysis*
chemical_list: D000393:Air Pollutants; D005579:Fossil Fuels; D005742:Gasoline; D052638:Particulate Matter; D001335:Vehicle Emissions