Carbon dioxide in steam condensate primarily comes from the breakdown of which substance?

Carbon dioxide in steam condensate mainly originates from the breakdown of bicarbonate. In water treatment and steam generation processes, bicarbonates are common alkalizing agents. When water containing bicarbonate is heated, particularly in steam systems, bicarbonate ions can decompose into carbon dioxide and water due to the increase in temperature. This reaction can be represented chemically as follows:

[ \text{2 HCO}_3^- \rightarrow \text{CO}_2 + \text{H}_2O + \text{OH}^- ]

As a result, the presence of carbon dioxide in steam condensate indicates that bicarbonate was present in the feedwater, breaking down when exposed to the heat of the steam system.

Understanding this connection is crucial for water treatment professionals, as it helps in monitoring and managing pH levels and the risk of corrosion in condensate lines caused by the presence of carbon dioxide. Proper water treatment strategies are essential to minimize the impact of this breakdown and maintain the integrity of steam systems.