What is the process of using hydrogen to bind with sulfur and nitrogen to remove impurities called?

The process of using hydrogen to bind with sulfur and nitrogen compounds to remove impurities is called hydrotreating. This technique is primarily utilized in the petroleum refining industry to improve the quality of fuels by eliminating harmful contaminants such as sulfur and nitrogen compounds, which can produce harmful emissions when burned.

During hydrotreating, hydrogen is introduced under high temperature and pressure in the presence of a catalyst. This reaction helps to saturate these compounds and convert them into more benign substances, thereby enhancing the overall quality of the final product and ensuring compliance with environmental regulations.

Other choices like hydrocracking and fluid catalytic cracking are related to converting heavier hydrocarbons into lighter, more valuable products, but they do not specifically focus on the removal of sulfur and nitrogen impurities. Isomerization involves restructuring molecules to change their configuration without altering the molecular formula, separate from the impurity removal process outlined in hydrotreating. Thus, hydrotreating is the correct term for this specific process of impurity removal using hydrogen.