Justification for Deep Desulfurization

In the past, reducing the sulfur content was mainly concerned with the heaviest products, most particularly the fuel oils. This development is explained by a legitimate concern to reduce SO2 emissions, notably in areas around large population centers. This is how low sulfur heavy fuels —having a maximum of 2% sulfur— and very low sulfur ( % sulfur) came into being. Currently the whole range of petroleum products, particularly motor fuels, should be strongly desulfurized for reasons we will explain hereafter. 

The French specification for sulfur in all types of gasolines —regular, premium, with or without lead— is 0.1% maximum, that is, 1000 ppm. This value is easily achieved because in the majority of commercial products, the content is less than 500 ppm. 

Influence of sulfur content in gasoline (from 500 to 50 ppm) in the reduction of pollutant emissions. j 

We have previously stated that the sulfur content of diesel fuel will be limited in Europe to 0.2% as of 1 October 1994 and to 0.05% as of 1 October 1996. 

These developments will reduce the total emissions of SO2 but the effect will remain limited. The reduction in sulfur levels in diesel fuel from 0.2 to 0.05% Is admitted to reduce yearly emissions of SO2 in France to only 10 to 12%. 

---