Internal Combustion Engines Emissions Quiz

Greenhouse gases like water vapor, carbon dioxide, methane, ozone, and others trap heat in the Earth's atmosphere, raising average temperatures.

The increase in Earth's average temperature due to the greenhouse effect, primarily caused by human activities like burning fossil fuels.

The primary cause of global warming, as human activities release greenhouse gases into the atmosphere.

Carbon dioxide, methane, nitrous oxide, and halocarbons are the main gases contributing to the greenhouse effect.

A measure of how much a gas contributes to global warming compared to carbon dioxide.

The process of converting the carbon bound in fossil fuels into carbon dioxide, released into the atmosphere, primarily through burning.

A metric used to evaluate the overall emissions of greenhouse gases, expressed in terms of equivalent carbon dioxide emissions.

The increase in the concentration of certain greenhouse gases like carbon dioxide, primarily attributed to human activities like industrial processes, deforestation, and fossil fuel combustion.

In ideal combustion, the primary products are water (H2O), carbon dioxide (CO2), and nitrogen (N2). However, real-world combustion is not ideal, and many other pollutants are also produced.

Carbon dioxide (CO2) makes up only about 14% of exhaust gases from gasoline and diesel engines. This means other gases are also significant contributors to pollution.

Nitrogen oxides (NOx) are a major pollutant emitted by both spark ignition and diesel engines.

Carbon monoxide (CO) is another pollutant emitted by spark ignition engines. It is a colorless, odorless, and poisonous gas.

Unburned hydrocarbons (HC) are emitted from spark ignition engines and can contribute to smog and other air quality issues.

Catalytic converters are fitted to vehicles to reduce harmful emissions from the engine exhaust before they are released into the environment.

Diesel engine exhaust contains significant amounts of particulate matter (PM), which are tiny particles that can contribute to respiratory problems and other health issues.

Diesel engines are not a significant source of carbon monoxide (CO) compared to spark ignition engines.

Catalytic converters and particulate traps remove pollutants from exhaust gases before they exit the vehicle.

Catalyst effectiveness relies on reaching a specific temperature, typically around 250 degrees Celsius.

Incomplete combustion in a fuel-rich mixture leads to the production of carbon monoxide.

Unburned hydrocarbons, or HC, are released when there's insufficient oxygen for complete combustion.

Hydrocarbons encompass a wide range of compounds containing hydrogen and carbon.

Aliphatic hydrocarbons lack strong scents, while cyclic aromatic hydrocarbons like benzol and toluol have discernible odors.

Nitrogen oxides form during combustion due to reactions involving nitrogen and oxygen in the air.

Nitrogen oxides are a group of compounds containing nitrogen and oxygen, often generated as a byproduct of combustion.

The ratio of nitrogen dioxide (NO2) to nitrogen oxide (NO) in exhaust gases, typically higher in diesel engines than gasoline engines.

Unburned hydrocarbons in the exhaust gases are a result of incomplete combustion. They are reduced when torque (engine load) increases due to higher combustion temperatures.

Secondary reactions in the expansion phase of combustion convert unburned hydrocarbons (HC) into carbon dioxide (CO2) and water (H2O).

Increased engine speed reduces the time for combustion, leading to more incomplete combustion and higher hydrocarbon emissions.

Nitrogen oxides (NOx) emissions peak at a slightly lean air-fuel ratio (about 1.05 to 1.1).

Advancing ignition timing increases combustion temperature, which shifts chemical equilibrium towards greater NOx formation.

Soot formation is minimal in gasoline engines with stoichiometric mixtures but can occur with direct injection and stratified charge due to localized rich zones or fuel droplets.

Diesel engines typically have a higher NO2/NO ratio, with the highest value at light load due to cooler regions that quench the conversion of NO2 back to NO.

A warning light on a vehicle's dashboard that indicates a malfunction in the emission system, potentially causing excessive emissions above legal limits.

A set of regulations established by the European Union to limit the amount of carbon dioxide (CO2) emitted by new passenger cars.

A formula used to calculate the specific CO2 emissions of a vehicle based on its mass and the overall fleet target. This formula helps determine if a car meets the CO2 emission standards set by the EU.

The average mass of all new passenger cars produced by a manufacturer. This figure is used in the CO2 emission calculation formula to determine the specific emissions of each vehicle.

A proposed revision to the European Union's regulations on CO2 emissions for heavy-duty vehicles like trucks and buses. The goal is to significantly reduce emissions by 2030 and 2040.

A combustion mode where fuel is injected into a localized area of the combustion chamber, creating a rich mixture, leading to higher efficiency and lower emissions.

A type of engine operation where the fuel is injected into the cylinder close to the end of the compression stroke, resulting in a faster and more efficient combustion process.

The process of returning a portion of the exhaust gas back into the combustion chamber, lowering combustion temperatures and reducing NOx emissions.

A type of combustion process where a small portion of the fuel mixes with air before entering the cylinder, resulting in a lean mixture and lower emissions.

The main byproducts of incomplete combustion in diesel engines, consisting primarily of soot particles with adsorbed organic compounds.

Reducing NOx emissions in diesel and gasoline engines by returning a portion of the exhaust gas into the combustion chamber, diluting the charge and lowering combustion temperature.

A chemical reaction where molecules are broken down into smaller particles, often requiring energy input.

The ability of a substance to absorb heat energy, measured as the amount of heat needed to raise the temperature of a specific amount of the substance by one degree.