Physical Chemistry of Aqueous Systems: Meeting the Needs of Industry

ISBN Print: 978-1-56700-034-4

ISBN Online: 978-1-56700-445-8

INFLUENCE OF ORGANICS THERMOLYSIS PRODUCTS - ACETIC AND FORMIC ACIDS - ON DISTRIBUTION RATIOS OF CHLORIDES BETWEEN WATER AND STEAM

DOI: 10.1615/ICPWS-1994.1010
pages 800-808

Abstract

Organic thermolysis products encountered in the operating medium have an influence on the contamination of saturated steam by cycle metallurgy corrosion products, sulfates, chlorides etc. Chlorides in steam are prohibited, because they cause failure of cycle materials, in particular, in the phase transition zone of turbines. Therefore, the problem of the influence of aqueous organics on chloride contamination of saturated steam is of primary importance. The aim of this study was to determine distribution ratios of chlorides between steam and water in the presence of acetic and formic acids. The experiments were conducted at pressures of 40, 70, and 100 ata (saturation temperatures 250, 285, and 310°C) for the following treatment chemistries: without additions, AVT (pH=8.5), and oxygenated treatment. Demineralized and deaerated water with a feed of the corresponding treatment chemicals was used for preparation of initial solutions. During experiments we measured content of chlorides, organics, pH, and conductivity. It was found that acetic acid in water increases the distribution ratio of chlorides. Formic acid is decomposed at t > 200°C. Based on experimental data proposals on the possible forms of existence of chlorides in water and steam at high parameters were made.