What type of particulate is produced from burning fuels?

When fuels burn, they can produce a range of particulate matter, of which unburned hydrocarbons are a significant component. During combustion, not all of the fuel is converted into gases like carbon dioxide and water vapor. Some of it may not be combusted completely, leading to the release of unburned hydrocarbons into the atmosphere. This is particularly common in combustion processes that are not optimally efficient, such as in car engines or industrial boilers.

Unburned hydrocarbons are significant as they contribute to air pollution and can have various environmental and health effects, including the formation of smog. In contrast, while carbon dioxide, water vapor, and sulfuric acid can also be produced during the burning of fuels, they do not specifically refer to particulate matter released from incomplete combustion. Carbon dioxide and water vapor are present in gaseous forms, and sulfuric acid typically forms as a result of sulfur in fuels reacting with oxygen and water vapor in the air, rather than being emitted as a direct product of the burning process itself.