Reduction of fine particulate matter (PM2.5) emission from light-duty diesel vehicle idling using compressed natural gas (CNG) in dual fuel mode

Abstract

Fine particulate matter (PM2.5) emission causes health problems and deaths of people in densely populated cities who cannot handle air pollution. The emission is caused by different sources and effects such as wildfire smoke, exhaust fumes from industry and traffic, and some effects such as wind and precipitation. Diesel engines, highly used for commercial vehicles, produce much higher PM2.5 emissions compared to other engines and are one of the most sources of air pollution in crowded cities. Due to high traffic in megacities, the vehicles are forced to run in idle mode most of the time and produce PM2.5 emissions countlessly. Implementing natural gas for the diesel engine is attractive for reducing the emission and energy price. In this work, the origin equipment manufacturer (OEM) electronic control unit (ECU) of a light-duty diesel vehicle was removed and replaced by a programmable ECU to apply the natural gas. The engine parameters were tuned and controlled to achieve lower exhaust emission from a tailpipe. Those variables are fuel quantity (diesel and natural gas), inlet air quantity, diesel injection timing, and fuel pressure at proper engine coolant temperature and supply voltage. PM2.5 air detector sensor was used for monitoring the air pollution from an exhaust pipe of the vehicle on idle mode. The results showed that the PM2.5 emission during idle operation in diesel mode was extremely reduced by using proper parameters in the dual-fuel mode. The emission results were varied related to natural gas quantity and diesel injection timing. Emissions of the transitions between two modes were shown experimental results.