Polyphosphate-containing composite corrosion and scale inhibitor, application thereof and method for inhibiting corrosion of sulfur-containing circulating cooling water

Abstract

The invention relates to the field of sulfur-containing circulating cooling water corrosion, and discloses a polyphosphate-containing composite corrosion and scale inhibitor, an application thereof and a method for inhibiting corrosion of sulfur-containing circulating cooling water. The composite corrosion and scale inhibitor contains polyphosphates, organic phosphonic acid, a copolymer of acrylicacid, 2-acrylamido-2-methylpropanesulfonic acid and hydroxypropyl acrylate and a copolymer of acrylic acid and hydroxypropyl acrylate, wherein the weight ratio of the polyphosphates to the organic phosphonic acid to the copolymer of acrylic acid, 2-acrylamido-2-methylpropanesulfonic acid and hydroxypropyl acrylate to the copolymer of acrylic acid and hydroxypropyl acrylate is 1:(1.2-1.8):(1.5-3):(1.5-3). The method provided by the invention is more suitable for low-hardness low-alkali sulfur-containing circulating cooling water after the pH value of sulfur-containing circulating cooling wateris adjusted to be 9.5-10 and the concentration of calcium ions is adjusted to be 200-300 mg/L, and a good corrosion and scale inhibition effect can be obtained. Through the method, corrosion of sulfides in the sulfur-containing circulating cooling water to water cooling equipment can be effectively inhibited without using a large amount of reagents and fresh water.

Description

technical field [0001] The invention relates to the field of sulfur-containing circulating cooling water corrosion, in particular to a polyphosphate-containing composite corrosion and scale inhibitor and its application and a method for inhibiting corrosion of low-hardness and low-alkali sulfur-containing circulating cooling water. Background technique [0002] In recent years, the processing of highly corrosive high-sulfur crude oil in refining units will cause corrosion and perforation of equipment, and leakage of materials into circulating water will occur. Sulfides in crude oil can be divided into inorganic sulfur and organic sulfur. Organic sulfur includes mercaptans, sulfides, disulfides, polysulfides, cyclic sulfides, and thiophenes. 2 S. These substances can directly corrode the metal. If the corrosion perforation causes material leakage, the leaked material will enter the circulating cooling water, causing serious deterioration of the water quality of the circulati...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the problems of the prior art in the process of inhibiting the corrosion of sulfur-containing circulating cooling water, such as the large amount of corrosion and scale inhibitors, the large consumption of fresh water, the large amount of sewage, and the high operating costs, and to provide a new Composite corrosion and scale inhibitor containing polyphosphate and its application in inhibiting corrosion of sulfur-containing circulating cooling water, and a method for inhibiting corrosion of sulfur-containing circulating cooling water, the concentration of calcium ions in the sulfur-containing circulating cooling water is 50- 180mg / L, total alkalinity 50-180mg / L, in which calcium ion concentration and total alkalinity are calculated as calcium carbonate