Sulfur can almost always be found in feedstocks and petroleum products. 1 As it is thought to be an undesirable contaminant that results in the formation of harmful pollutants like sulfur oxides, it is typically removed during crude oil processing. Image credit: industryviews/Shutterstock.com While the removed sulfur can be utilized to synthesize other chemicals, like sulfuric acid, crude oil that has a high sulfur content usually has a lower monetary value and is often known as ‘sour crude.’ The lower value denotes the higher costs which come with refining crude oil with this chemical composition. The sulfur content can cause further expenses through damage to refinery equipment as it can also prove corrosive.