Evaluating  Air Emissions and Fuel Efficiency of Solid Waste Collection Vehicles

Investigators: University of Nebraska at Lincoln and North Carolina State University

Start Date:
Mar 2012

Award Amount:
$262,602

This study represents one of the first to comprehensively evaluate the influence of vehicle characteristics and fuel type on emissions from solid waste collection vehicles. The data collected in this study represent emissions from real-world collection scenarios and a large number of collection vehicles. The collection of emissions data from real-world operating solid waste collection vehicles posed a number of challenges. Despite these challenges, emissions data was collected from 24 collection vehicles representing frontload, sideload and rolloff configurations. Hundreds of hours of data was collected over thousands of miles of operation by the 24 vehicles.

Using this data, we are able to report duty cycle average emissions rates for each vehicle as well as route characterization data, as GPS data was collected on each vehicle route. To date, limited data exists on route characterization information for solid waste collection. The data collected here on times between stops, at stops, at landfill and between landfill and stops and route distances can be used for modeling solid waste collection systems and/or life cycle assessment for solid waste management. The data collected in this study compare well with the limited data that are currently available on times and collection distances for sideloader collection vehicles. To our knowledge, these data represent some of the first publically available data on route characterization for rolloff and frontloader refuse collection vehicles.

A multiple regression analysis was performed to evaluate the influence of variables such as vehicle and engine year, vehicle type, fuel type and emissions controls on each type of emissions. In general, vehicle year and engine year were consistently found to be a significant predictor for duty cycle average emissions rates when all trucks were considered together in the regression with the exception of hydrocarbon emissions, which were not found to be significantly influenced by engine year or vehicle year. However, these factors were not always significant when emissions from specific operating mode ranges or road grades were considered individually. The type of vehicle (front load, side load, roll-off) was a significant predictor when all trucks were included in the regression model for duty cycle average CO2, CO, and hydrocarbons. Vehicle type was not a significant factor for NOx or PM duty cycle average emissions when all trucks were considered together. The influence of fuel type was mixed with fuel type (CNG or diesel) not significant for duty cycle average emissions of CO2 or hydrocarbons, but it was significant for duty cycle average emissions of CO, NOx, and PM. In general, these results indicate that vehicle year and engine year can significantly influence emissions, but other factors such as route characteristics and driver characteristics are also influencing the emissions rate, as these factors were not found to be consistently significant across all operating mode categories or road grades evaluated. Further work is needed to evaluate the influence of road characteristics or driver characteristics on emissions rates. When CNG vehicles were considered alone, the only factor evaluated (vehicle type) was rarely determined to be a significant predictor for emissions rates.

In summary, the data collected in this study provide useful information to the solid waste industry on the influence of vehicle characteristics and fuel type on emissions rates, as well as allowing for quantification the effects of solid waste collection on CO2 emissions from the solid waste industry.

Publications/Reports
Final Report

Accepted Manuscript
Real-World Activity, Fuel Use, and Emissions of Diesel Side-Loader Refuse Trucks
Gurdas S. Sandhu, Ph.D., H. Christopher Frey, Ph.D., Distinguished University
Professor, Shannon Bartelt-Hunt, Ph.D., P.E., Associate Professor, Elizabeth Jones,
Ph.D, Associate Professor

Atmospheric Environment 92 (2014) 557e565
In-use measurement of the activity, fuel use, and emissions of frontloader refuse trucks
Gurdas S. Sandhu a, H. Christopher Frey a,*, Shannon Bartelt-Hunt b, Elizabeth Jones b

Gurdas S. Sandhu, H. Christopher Frey, Shannon Bartelt-Hunt & Elizabeth Jones (2015) In-use activity, fuel use, and emissions of heavy-duty diesel roll-off refuse trucks, Journal of the Air & Waste Management Association, 65:3, 306-323, DOI: 10.1080/10962247.2014.990587