Petroleum refineries are typically large, sprawling industrial complexes with extensive piping running throughout, carrying streams of fluids between large chemical processing units, such as distillation columns.

The refining process breaks crude oil down into its various components, which are then selectively reconfigured into new products. The basic steps in the refining process are:

1. Distillation: The first step in the refining process is distillation. This is a process of separating the different components of crude oil based on their boiling points. The crude oil is heated to a high temperature, and the different components vaporize and are then condensed into liquids.
2. Conversion: The second step in the refining process is conversion. This is a process of converting the heavier components of crude oil into lighter, more useful products. This is done through a variety of processes, such as cracking, reforming, and isomerization.
3. Treatment: The third step in the refining process is treatment. This is a process of removing impurities from the refined products. This is done through a variety of processes, such as desulfurization, denitrogenation, and dewaxing.

The products of petroleum refining are used in a variety of applications, including:

• Transportation: The most common use of petroleum products is for transportation. Gasoline, diesel fuel, and jet fuel are all petroleum products that are used to power vehicles.
• Heat and power: Petroleum products are also used to generate heat and power. Fuel oil is used to heat homes and businesses, and it is also used to generate electricity.
• Industrial uses: Petroleum products are also used in a variety of industrial applications. Kerosene is used to heat aircraft, and it is also used as a solvent. Naphtha is used to make plastics and other chemicals.

Petroleum refineries are an important part of the global economy. They provide the products that we use every day, and they also play a role in the production of other important products, such as plastics and chemicals.