Which process specifically targets the rearrangement of carbon atoms in hydrocarbons?

The process that specifically targets the rearrangement of carbon atoms in hydrocarbons is isomerization. Isomerization involves converting a straight-chain hydrocarbon into its branched isomers, optimizing the properties, such as octane rating, of the fuel produced. This process is essential in the refining industry to improve the quality of gasoline by enhancing its performance and reducing emissions.

In isomerization, while the molecular structure of the hydrocarbons changes, the total number of carbon atoms remains the same. This rearrangement increases the efficiency of fuel combustion, making it more desirable for high-performance applications.

The other processes mentioned serve different purposes; for instance, hydrotreating focuses on removing impurities like sulfur from hydrocarbons, while fluid catalytic cracking is primarily used for breaking larger hydrocarbon molecules into smaller, more useful ones. Hydrocracking also breaks down larger molecules but mainly in the presence of hydrogen. Each of these processes plays a critical role in refining, yet none specifically rearranges carbon atoms within the molecule itself like isomerization does.