pH Measurement in Refining Tail Gas Clean-Up

Sulfides accumulate in quench water and can cause corrosive acidic conditions, poisoning a pH sensor's reference. pH is measured and controlled by the addition of amine or caustic in order to prevent corrosion. And hard water produces scale that coats a pH sensor's reference junction. The Rosemount™ 3500P pH Sensor provides continuous pH measurement as it includes a poison-resistant electrolyte that reacts with the sulfide before it can damage the reference. The double-junction design uses two layers of porous junctions to separate the process chemicals from the reference electrode and allows the outer reference solution to be conveniently refilled.