Characterization of Amines Under High Temperature Conditions and Their Use for Boiler Water Treatment

摘要

In the boiler water system, it is apparent that use of low volatility amine is effective to control pH of feed water and to maintain boiler water at higher pH even though makeup water is contaminated with organic substances which thermally decompose to organic acids. Various amines were characterized in the view of volatility, thermal stability and dissociation behavior at high temperature by using experimental boiler apparatus with maximum pressure up to 10.5 MPa and with maximum exhausting steam temperature up to 600 °C after attached superheater. One low volatility amine which is suitable for boiler water treatment was selected. The selected low volatility amine was applied to a boiler with superheater and a low-pressure special circulating boiler of which recovered steam condensate has been recently sometimes mixed with that of power generating boilers at the same site. It was confirmed that the amine showed good expected performance in the both boiler systems with the viewpoints of pH keeping ability at higher values and corrosion inhibition effect.