Why is it important to remove the sulfur compounds from crude oil?

Sulfur in crude oil is an impurity. It can give off the
smell of rotten eggs when found as hydrogen sulfide. It can also be found as elemental
sulfur. Sulfur can go on to become  a secondary air pollutant when the sulfur combines
with water in the atmosphere producing sulfuric acid. This is a compound that is found
in acid rain and is very corrosive. In order to process crude oil into gasoline, sulfur
is removed first. Sulfur in fuels can lead to respiratory problems, asthma, chronic
fatigue syndrome and can affect the sense of smell. As pollution laws have become
stricter in the United States, the gasoline products have become much
cleaner.