Packed bed absorber (PBA)

In the PBA process flue gas passes in a cross- or counter-flow through a reaction chamber filled with a granular sorbent. Gravity draws the reagent through the reaction chamber, after which it is removed at the bottom of the PBA. The removal performance of a conventional PBA using natural limestone is quite high for SO₃ and HF (> 95-98%) but rather limited for HCl (20-30%) and SO₂ (10-20%). 

A packed bed reactor consists of a vessel filled with reactive material. While passing through the vessel, the pollutants are captured by the filler. The filler needs to be replaced after a certain time, which varies from plant to plant.

The PBA is particular suitable for industrial processes with a peak release of acidic pollutants. Sorbacal® HCG significantly increases the removal performance for HCl and SO₂. This makes it an attractive alternative in PBA processes for new applications, like the desulphurization of marine diesel engines.

Sorbacal^® C, a natural limestone CaCO₃ sorbent in the form of “chippings”, is typically used for PBAs.

For greater removal performance we recommend Sorbacal^® G: spherical granulated particles consisting of CaCO₃ and Ca(OH)₂. The residual Ca(OH)₂ content in combination with the higher porosity and surface area of the granulates enables significantly better removal rates for HCl (> 70%) and SO2 (30-35%). With multi-stage PBAs, even higher rates have been achieved for HCl and SO₂ (>80%). 

• Sorbacal^® C
• Sorbacal^® G