Compound deoxygenation corrosion inhibitor for boiler water supply and preparation method thereof

Abstract

The invention provides a compound deoxygenation corrosion inhibitor for boiler water supply. The deoxygenation corrosion inhibitor includes a variety of organic components, all the components cooperate and can achieve rapid and effective removal of dissolved oxygen from boiler water, and overcome the shortcoming of low deoxygenation efficiency of single deoxidant. The deoxygenation corrosion inhibitor obtained by adjusting the organic alkalizer content can be applied to ordinary pressure, medium-pressure and high-pressure boilers, and has wide application range. Oxime and hydrazide have strong reducibility, can quickly remove dissolved oxygen from boiler water, and at the same time can generate a layer of dense black ferroferric oxide passivation film on the boiler inner wall so as to prevent further corrosion of the boiler. The deoxygenation corrosion inhibitor provided by the invention has no need for ammonia water to serve as the pH regulator, and avoids ammonia corrosion. The deoxygenation corrosion inhibitor provided by the invention is composed of all-organic components, does not introduce inorganic impurities or reaction by-products, does not affect the boiler blowdown and steam quality, and is a liquid product, and has the advantages of no toxicity, no flash point, and safe and convenient use and operation.

Description

technical field [0001] The invention belongs to the fields of chemical industry and water treatment, and in particular relates to a composite type boiler feed water deoxidizer and corrosion inhibitor and a preparation method thereof. Background technique [0002] Boilers are bulky and difficult to install and replace, so regular maintenance and cleaning are required to slow down their aging speed. The corrosion of boiler equipment is mainly caused by the presence of oxygen in the steam cycle. Oxygen is chemically active and is cathodic depolarization. Oxygen dissolves in water to form dissolved oxygen, which is corrosive. Oxygen scavenger can remove dissolved oxygen in water, thereby reducing dissolved oxygen in boiler feed water and inhibiting boiler corrosion caused by dissolved oxygen. [0003] At present, there are many kinds of oxygen scavenger for boiler feed water, and there are also many problems. (1) Hydrazine in the currently commonly used hydrazine oxygen scave...

AI Technical Summary

Problems solved by technology

(1) Hydrazine in the currently commonly used hydrazine oxygen scavenger is volatile, flammable, and explosive, and may cause carcinogenic problems. There are still residues in the steam and cannot be used in daily life. The reaction speed with oxygen is affected by temperature, pH and excess The amount of ammonia has a great influence. At high temperature, the ammonia generated by decomposition will form soluble copper ammonium ions with copper, that is, ammonia corrosion of copper or its alloys will occur; (2) Oxime compounds, hydroxylamine compounds and other oxygen scavengers exist The problem of low deoxygenation efficiency and the need to assist ammonia water to adjust pH during use; (3) Carbohydrazide oxygen scavengers cannot be used alone, and need to assist ammonia water to adjust pH; (4) Erythorbic acid and its sodium salt, etc. Decomposition products after deoxygenation: lactic acid, formic acid, acetic acid, etc. negatively affect process parameters

[0004] Patent CN1854083A discloses a multi-component boiler oxygen scavenger, which is composed of 70-80% catalytic sodium sulfite, 10-20% 2,3-diamino-piperidine, and 5-10% cyclohexylamine according to the weight percentage. The multi-component boiler oxygen scavenger of this invention can quickly remove dissolved oxygen in boiler water, but the multi-component boiler oxygen scavenger provided by this invention contains sodium sulfite, which is not suitable for solving the problem of high-pressure boiler water supply system