Which of the following is NOT a main process involved in crude oil refining?

Hydrolysis is not a main process involved in crude oil refining. The primary processes in crude oil refining typically include distillation, cracking, and treating.

Distillation is a fundamental method used to separate crude oil into its component fractions based on boiling points. This process is crucial for obtaining various petroleum products, such as gasoline, diesel, and kerosene.

Cracking refers to the process of breaking down larger hydrocarbon molecules into smaller, more useful ones. This is essential for producing high-demand fuels and chemical feedstocks.

Treating involves removing impurities from petroleum products to enhance their quality and ensure they meet regulatory standards. This step is vital for refining operations to deliver clean and usable fuels.

In contrast, hydrolysis is a chemical process that involves the reaction of a substance with water, typically relevant in other fields such as organic chemistry or biochemistry, rather than crude oil refining.