Sour crude is crude oil with a high sulfur content, typically exceeding 0.5% by weight, which distinguishes it from sweet crude, its low-sulfur counterpart. The term "sour" reflects the oil’s unpleasant odor, reminiscent of rotten eggs, due to the presence of hydrogen sulfide and other sulfur compounds. Extracted from various global oil fields, such as those in the Middle East, Venezuela, or Canada, sour crude requires more complex and costly refining processes to remove sulfur impurities, which can corrode equipment and contribute to environmental pollution if not properly managed. These additional processing steps make sour crude less desirable than sweet crude, often resulting in a lower market price, though its abundance in certain regions makes it a significant resource for refineries equipped to handle it. The sulfur content not only affects refining but also influences the quality of end products like gasoline and diesel, necessitating strict regulatory controls to minimize emissions.
