Hydroprocessing is a refining process that uses hydrogen to remove impurities from petroleum products. This technique helps improve the quality of fuels by eliminating sulfur, nitrogen, and other unwanted elements, making them cleaner and more efficient for use in engines. The process typically involves two main methods: hydrocracking and hydrotreating. In hydrocracking, heavy oils are broken down into lighter, more valuable products like gasoline and diesel. In hydrotreating, existing fuels are treated to enhance their properties, ensuring they meet environmental regulations and performance standards.