How do you assess the environmental and health impacts of IC engine exhaust emissions?

1 Types of emissions

IC engine exhaust emissions can be classified into four main categories: gaseous, particulate, noise, and thermal. Gaseous emissions include carbon monoxide (CO), carbon dioxide (CO2), hydrocarbons (HC), nitrogen oxides (NOx), and sulfur oxides (SOx). Particulate emissions consist of solid or liquid particles of various sizes and compositions, such as soot, ash, metals, and organic compounds. Noise emissions are the unwanted sound waves generated by the engine operation and exhaust system. Thermal emissions are the heat released by the engine and exhaust system, which can affect the ambient temperature and contribute to global warming.

2 Methods and tools

To assess the environmental and health impacts of IC engine exhaust emissions, you need to measure and analyze them using appropriate methods and tools. The measurement methods can be divided into two types: laboratory and field. Laboratory methods involve testing the engine or vehicle on a dynamometer or a test bench under controlled conditions and using standardized procedures and instruments. Field methods involve testing the engine or vehicle on the road or in the real environment using portable or remote sensors and devices. The analysis tools can be divided into two types: empirical and numerical. Empirical tools use statistical or experimental data to estimate the emissions and their impacts. Numerical tools use mathematical models and simulations to predict the emissions and their impacts.

3 Strategies and technologies

To reduce the environmental and health impacts of IC engine exhaust emissions, you need to implement effective strategies and technologies. The strategies can be divided into two types: fuel and engine. Fuel strategies involve using alternative or cleaner fuels, such as biofuels, natural gas, hydrogen, or electricity, that have lower emissions or carbon footprint. Engine strategies involve optimizing the engine design, operation, and maintenance, such as improving the combustion efficiency, reducing the friction losses, or performing regular tune-ups. The technologies can be divided into two types: exhaust gas recirculation (EGR) and aftertreatment devices. EGR is a technique that recirculates a portion of the exhaust gas back into the engine intake, reducing the peak temperature and pressure, and thus the NOx formation. Aftertreatment devices are systems that treat the exhaust gas before it leaves the tailpipe, such as catalytic converters, particulate filters, selective catalytic reduction, or lean NOx traps, that remove or convert the pollutants into less harmful substances.

4 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?