What are the greenhouse gas emissions from ethanol combustion?

Ethanol combustion produces carbon dioxide (CO2), water (H2O), and small amounts of nitrogen oxides (NOx).

When ethanol, a biofuel, is burned in the presence of oxygen, it undergoes a chemical reaction known as combustion. The primary products of this reaction are carbon dioxide (CO2) and water (H2O). However, depending on the conditions of combustion, small amounts of nitrogen oxides (NOx) may also be produced.

The chemical equation for the combustion of ethanol is: C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l). This equation shows that for every molecule of ethanol burned, two molecules of carbon dioxide and three molecules of water are produced.

Carbon dioxide is a greenhouse gas, which means it contributes to global warming by trapping heat in the Earth's atmosphere. However, it's important to note that the carbon dioxide produced by burning ethanol is part of a short-term carbon cycle. The plants that are used to produce ethanol absorb carbon dioxide from the atmosphere as they grow, which can offset the emissions from ethanol combustion.

Nitrogen oxides, on the other hand, are not a major product of ethanol combustion, but they can be produced in small amounts, especially at high temperatures. Nitrogen oxides are also greenhouse gases and can contribute to air pollution, causing problems like smog and acid rain.

In conclusion, while ethanol combustion does produce greenhouse gases, it is considered to be a more environmentally friendly fuel compared to fossil fuels. This is because the carbon dioxide it emits is part of a short-term carbon cycle, and it produces fewer harmful emissions overall.