ESD-SIC produces silicon carbide by reacting sand (SiO2) with petroleum coke, a product from petroleum refining. Approximately 2 tonnes of low calorific process gas is produced during the production of 1 tonne of SiC. This gas is extracted from the furnace process and contains approximately 1% sulphur-containing compounds from the petroleum coke. The process gas is burned to generate energy.
In the 1980s, environmental acidification was a major issue. Sulphur dioxide (SO2) emissions from combustion processes were a significant contributor to the problem. In 1991, ESD-SIC commissioned its desulphurisation plant, reducing annual SO2 emissions to the atmosphere caused by burning its process gas by more than 90%. The sulphur recovered in the desulphurisation plant is sold as a sustainable raw material. It is mainly used in agriculture as a fungicide, fertiliser and soil conditioner, but is also used in industrial processes such as tyre manufacturing, the rubber industry, and industrial gas production.