Combustion and Air Quality: Emissions Monitoring
Air quality monitor (Pod) placed behind a truck tailpipe; CO2 emissions data plotted above.
As a class, students use a low-cost air quality monitor (a rentable “Pod”) to measure the emissions from different vehicles. By applying the knowledge about combustion chemistry that they gain during the pre-activity reading (or lecture presentation, alternatively), students predict how the emissions from various vehicles will differ in terms of pollutants (CO2, VOCs and NO2), and explain why. Combustion is a common burning reaction that occurs often in the world around us and that we look at when studying air quality because the reaction emits many different common pollutants. After data collection, students examine the time series plots as a class—a chance to interpret the results and compare them to their predictions. Short online videos and a current event article help to highlight the real-world necessity of understanding and improving vehicle emissions. Numerous student handouts are provided. The activity content may be presented independently of its unit and without using an air quality monitor by analyzing provided sample data.
This activity walks students through a test and analyze experience that mirrors the experiences of engineers who design cars and engineers who regulate their emissions. Industrial, mechanical and electrical engineers work together to design the most efficient and well-functioning cars. It is important to continually advance automotive technology in order to improve efficiency and safety, and decrease environmental impact. Emissions are regulated to ensure that car companies continue to improve automotive technology.
The activity begins with background information on combustion chemistry, obtained either by a reading or slide presentation, including extending these concepts to vehicles, covering how vehicle operation/design and control technologies impact combustion, and thus emissions. This shows students an example of engineers applying scientific concepts to automobile design. During data collection, students carry out a simplified version of what regulatory agencies do—measuring vehicle emissions and interpreting the data. Students are also tasked to critique the design of the data collection procedures and discuss ways to ensure consistent data collection processes from vehicle to vehicle.
After this activity, students should be able to:
- List the products of complete and incomplete combustion and explain what physical and chemical characteristics lead to the different outcomes.
- Provide examples of how changes made by engineers over time to vehicle designs and control technologies have reduced the emission of harmful pollutants.
- Interpret emissions data from a plot, using concepts from combustion chemistry and vehicle characteristics to support the explanation.
- Use the Pods (air quality monitors) to collect data on their own.