Crude oil naturally contains sulfur and burning the fuels made from it generates sulfur oxides. The hydrogen supplied by Air Liquide is used to remove this sulfur and produce cleaner fuels.
Fossil fuels naturally contain sulfur. Crude oil contains on average 1.5% sulfur, which is set to rise by about 5% by 2012 due to the use of lesser quality crudes.
The use of fossil fuels generates sulfur oxides, or SOx. These substances are responsible for smog above cities, acid rain and respiratory problems for human beings. Sulfur also hinders the functioning of catalytic converters that are fitted to car exhausts.
To limit these effects, it is important to reduce emissions of SOx. To do so, the sulfur in the crude oil must be removed at the refining stage. States have implemented increasingly strict legislation concerning the maximum sulfur content in fuels.
Hydrogen is used by refiners to remove the sulfur in fuels and make them cleaner. The hydrogen supplied by Air Liquide is used each year to prevent the release of about 700,000 tons of SOx, which is almost twice the total SOx emission of a country like France.