Cement kilns create sulfur emissions which are directly related to the sulfur content of their fuels – primarily coal. Low sulfur coal is more costly to use compared with high sulfur coal. In order to comply with EPA limits cement kilns must either use a low sulfur coal at an increased cost or install a sulfur scrubber at the back end of the kiln similar to a coal fired power plant. The capex for a sulfur scrubber can be 20 – 30 million dollars. SCB International has developed the following patent pending method of reducing sulfur emissions without the need for a scrubber.
“A method of treating cement kiln fuel includes introducing an additive to a fuel component to form a fuel mixture. The fuel component includes a sulfur-generating combustible fuel and the additive includes a micronized lime component. The method further includes combusting the fuel component delivered in a combustion zone within a burning zone of a cement kiln. The sulfur generated by the combustion of the combustible fuel forms sulfur compounds with lime provided by the micronized lime component. The sulfur compounds fall to a bed of clinker forming along the burning zone and become resident in the clinker”
- Reduced SO2 emissions
- Added directly with the pulverized coal
- The micronized calcium or magnesium reacts with the sulfur from the fuel to form sulfate
- Increased sulfate in clinker, requiring less gypsum during finish grinding
- Ability to use more economical coal with higher sulfur content
- May be used continuously or as needed (buildups in preheater kilns)