Evaluating the ammonia emission from in-use vehicles using on-road remote sensing test

Area of Science:

• Environmental Science
• Automotive Engineering
• Air Pollution Control

Background:

• Ammonia (NH3) emissions from vehicles are a growing concern for air quality.
• Understanding real-world emissions from in-use vehicles is crucial for effective pollution control strategies.
• Previous studies often lack large-scale, on-road data for ammonia emissions.

Purpose of the Study:

• To analyze ammonia emission characteristics of in-use vehicles using on-road remote sensing data.
• To identify high-emitting vehicles based on manufacture year, emission standards, and fuel type.
• To evaluate the effectiveness of remote sensing technology in screening high ammonia emitters.

Main Methods:

• Conducted on-road remote sensing tests in Zhengzhou to collect a large dataset of vehicle emissions.
• Analyzed ammonia emission concentrations and factors for gasoline, diesel, and other fuel vehicles.
• Investigated the relationship between emission standards and ammonia emission levels and high-emitter percentages.

Main Results:

• Average ammonia emission concentrations fluctuated, with emission factors ranging from 0.30-0.47 g/kg (gasoline), 0.34-0.50 g/kg (diesel), and 0.29-0.60 g/kg (other fuels).
• Ammonia emission levels stabilized after the China III standard, showing no obvious downward trend.
• A small percentage of vehicles (top 10%) contributed disproportionately high ammonia emissions, with other fuel vehicles showing lower emissions within this high-emitter group.

Conclusions:

• Improving vehicle emission standards effectively reduces overall exhaust pollution.
• Remote sensing technology is a powerful tool for identifying high ammonia-emitting vehicles.
• Ammonia emissions from diesel and other fuel vehicles are significant and require attention, alongside gasoline vehicles.