Application Note: Lime / Limestone Wet Scrubbing System For Flue Gas Desulfurization

Wet scrubbers are used in utilities, paper mills, and chemical plants to remove sulfur dioxide (SO2) and other pollutants from gas streams. Undesirable pollutants are removed by contacting the gases with an aqueous solution or slurry containing a sorbent. The most common sorbents are lime (Ca[OH]2) and limestone (CaCO3). Rosemount Analytical pH equipment is used to control the feed rate of these chemicals.

?The Rosemount Analytical Model 3300HT/3400HT PerpH-X®1 high performance sensors are recommended for measurement in harsh scrubbing process applications. Their recessed Accuglass®2 glass electrodes resist abra- sion or cracking due to the scouring action of suspended solids and the large-surface area Teflon liquid junctions resist fouling. Should the sensor ever become coated or fouled, the liquid junction may be replaced and the elec-trolyte replenished. If a disposable sensor is preferred, the Model 396 TupH®3 offers similar fouling resistance but can-not be rebuilt.