CFB Boiler Desulfurization Process

Desulfurization technology in circulating fluidized bed boiler is implemented using limestone dry desulfurization method, that is, the CaCO in boiler furnace through high temperature calcined breaks down into CaO, and reacts with SO in the flue gas, then generates the CaSO, which is discharged along with the slag, so as to achieve desulfurization purpose. CFB boiler desulfurization process can be mainly divided into three steps.

1. Limestone Calcination

For a circulating fluidized-bed boilers, CaCO in the limestone will break down into CaO after heated and calcination, when CO is precipitated, pores will occur and expand, increasing their surface area, and laying the foundations for the next step in sulfur reaction. Reaction equation is CaCO=CaO+CO

2. Precipitation and Oxidation of Sulfur

Sulfur in coal is generally existed with pyrite, organic salt, sulfate the three forms. Related tests show that, when coal is heating and burning, release of SO is in obvious stage. The pyrite after combustion and oxidation generates SO. The organic sulfur in 200 degree C decomposes and releases HS, sulfide, mercaptans, etc, these substances are oxidized and generated SO. Reaction equation is S+O=SO

3. Curing reaction of Sulfur

CaO reacts with precipitated SO to generate Sulfate. The reaction equation is CaO+SO+1/2O=CaSO

CFB boiler desulfurization technology can effectively reduce the sulfur emission, reduce the environment pollution and improve boiler’s social and economic benefits. Zhengzhou Boiler Co., Ltd. manufacture and offer excellent quality CFB boilers with high thermal efficiency up to 90%. Anyone needs the boiler for your projects, feel free to let us know, and we will provide custom-designed products for your needs!