Composite type sodium polysulfide corrosion inhibitor and preparation thereof

Abstract

The invention relates to compound type sodium polysulphide corrosion inhibitor, which is suitable for the hydrogenation cracking reaction effluent air cooler. The compound type sodium polysulphide corrosion inhibitor is formed by combining sodium polysulphide, benzotriazole and organic amine film forming agent, wherein, the organic amine film forming agent is the combination of one or more of sodium molybdate, sodium chromate and zinc sulfate. The product integrates complexing, dispersing, corrosion prevention and film forming into a whole, has good synergistic inhibition effect under the lowtemperature and the high temperature and has good corrosion inhibition on the corrosion of the sulfide and the prussiate, the corrosion rate is reduced obviously, the temperature at the air-cooled water outlet opening can be guaranteed effective not to rise, the temperature of the tube bundle is even, the current bias phenomenon can not be caused, and the protective film formed on the surface of the equipment is steadier.

Description

technical field [0001] The invention relates to a composite sodium polysulfide corrosion inhibitor, which is suitable for use in an air cooler for hydrocracking reaction effluent. Background technique [0002] There are a large amount of corrosive media such as hydrogen sulfide, ammonia, and a small amount of cyanide and chloride in the process stream of the hydrocracking reaction effluent air cooler. In the presence of water, various corrosion systems are formed, especially the corrosive medium cyanide , which also promotes other corrosion reactions. In order to inhibit the corrosion of equipment by cyanide, American CHEVRON research company has developed a kind of anti-corrosion and anti-scaling agent, that is, sodium polysulfide is added to the corrosive medium where cyanide exists, so that sodium polysulfide first reacts with the wall or pipe wall, and then A dense protective film of FeS is formed on the surface to protect the equipment or pipelines, and then sodium pol...

AI Technical Summary

Problems solved by technology

However, in hydrogenation and high-pressure air cooling, sodium polysulfide is easy to decompose into elemental sulfur when it meets air, which makes scaling on the mechanical seal of the high-pressure water injection pump seriously affect the service life of the high-pressure water injection pump, storage tank and pipeline, and the formed ferrous sulfide protective film Relatively loose, failed to achieve the expected anti-corrosion effect on the protective tube bundle

[0003] Chinese patent application 02117840.2 discloses a "special corrosion and scale inhibitor for surface evaporation and air cooling", which is compounded with zinc sulfate, acrylic acid-acrylic acid ester copolymer, hydroxyl 1-1-ethylene diphosphonic acid, and benzotriazole It is suitable for circulating water systems with high hardness and high alkalinity, and the anti-corrosion effect is not ideal under high temperature and the presence of cyanide