Final answer:
At 180°C, refinery gas, which includes lighter and more volatile hydrocarbons like propane and butane, is typically the component removed from petroleum through the fractional distillation process in the refining tower.
Step-by-step explanation:
At 180°C, the component of petroleum that is typically removed is refinery gas. In the process of refining crude oil, various hydrocarbons are separated based on their boiling points through a method known as fractional distillation. As the mixture of hydrocarbons heats up, the lighter components with lower boiling points condense at higher points in the refining tower. Among the options provided, refinery gas is the one that would condense at the lower temperatures typically seen at the top of the distillation column.
The process of separating crude oil into different components involves heating the crude until it vaporizes and then allowing the vapors to rise through the fractionating column. The various fractions of petroleum condense at different levels depending on their boiling points. Compounds with the lowest boiling points, like refinery gas, condense at the top of the column, while those with higher boiling points, such as kerosene and diesel, condense lower in the column.
Refinery gas is a mixture of the lightest and most volatile hydrocarbons, which include products like propane and butane, and is primarily used for heating or as a petrochemical feedstock.