Desulphurization

When fossil fuel coal is combusted in power stations to produce electricity, the sulfur contained within it is released into the atmosphere . The proportion of sulfur will vary depending upon the quality and the origin of the coal and is released in the form of sulfur dioxide [SO2], a gas. Our calcium carbonate fillers such as Desulfonit® can be added to remove the sulfur before it reaches the atmosphere. The fillers react chemically with the sulfur gas to form a calcium sulfate by-product called gypsum.


  • In a dry process, this reaction occurs in the furnace, and the by-product gypsum is burnt.
  • In a wet process, the chemical reaction takes place in the scrubber, forming gypsum as a by-product. This material can subsequently be used as an additive in cement, as a source of sulfur in fertilizers or in plasterboard manufacture.

Depending on the process and the quality of the calcium carbonate filler used, over 95% of the sulfur can be removed. The calcium carbonate needs to be as pure as possible and needs to have a precise particle size distribution. The sulfur released in the atmosphere directly influences the acidity of soil and natural waters (lakes, ponds, rivers) and is returned to the natural cycle in the form of acid rain.

Sustainability

Omya deposits are near important markets to guarantee efficient, long-term supply of high-quality calcium carbonates.