Which chemical is commonly used for oxygen scavenging in boiler systems?

Sodium sulfite is the chemical commonly employed for oxygen scavenging in boiler systems. Its primary function is to react with dissolved oxygen in the water, thereby preventing oxygen-induced corrosion in the boiler and related systems. This is crucial because oxygen, being corrosive, can deteriorate metal components over time, leading to system failures and increased maintenance costs.

When sodium sulfite is added to the water, it reacts with oxygen to form sodium bisulfate. This reaction helps to maintain the integrity of the boiler's metal surfaces and extends the lifespan of the equipment by minimizing corrosion issues.

While other chemicals listed, like calcium carbonate and potassium hydroxide, are used for different purposes such as pH adjustment or as alkalinity agents, they do not serve the specific function of oxygen scavenging. Sodium chloride primarily functions as a salt and is not effective in preventing oxygen corrosion in boiler operations. Hence, sodium sulfite is the appropriate choice for controlling oxygen levels in boiler systems.