Chemical cleaning agent for clearing impurities such as ferrous sulfide

Abstract

The invention relates to a chemical cleaning agent for clearing impurities such as ferrous sulfide, which is made of the following raw materials in percentage by weight: 1-15% of acidic chelating agent, 0.05-5% of surfactant, 1-20% of alkaline chelating agent, 5-30% of oxidant, 0.1-1% of corrosion inhibitor, 0.1-2% of cosolvent and the balance of water; the acidic chelating agent is preferably selected from citric acid; the surfactant is preferably selected from sodium dodecyl benzene sulfonate; the alkaline chelating agent is preferably selected from ammonia or disodium ethylene diaminetetraacetate; the oxidant is preferably selected from hydrogen peroxide; the corrosion inhibitor is preferably selected from polybasic phosphate (A ester); and the cosolvent is preferably selected from benzoic acid or sodium benzoate. The invention has the beneficial effects of effectively clearing dirt such as ferrous sulfide in devices at normal temperatures and avoiding the spontaneous combustion of the ferrous sulfide and has the characteristics of low cost, large dirt clearing amount, good dirt clearing effect, non-toxicity, safety, simple and convenient operation, and the like.

Description

Technical field [0001] The invention relates to the field of chemical engineering, and in particular to a chemical cleaning agent for removing impurities such as ferrous sulfide. Background technique [0002] During the processing, storage and transportation of sour crude oil, because most of the processing, storage equipment and transportation pipelines are made of carbon steel, carbon steel is easily corroded by sulfur to form FeS x Such materials and rust are deposited in related equipment and pipelines. With the widespread application of fiber liquid membrane mass transfer equipment in the field of oil desulfurization, FeS x Impurities such as rust, rust, and gums in oils are likely to cause clogging of this type of equipment. In addition, FeS x Contact with air is prone to spontaneous combustion leading to fires, explosions and other accidents, which seriously affects the long-term operation of petrochemical plants and poses a great threat to production safety. Therefore, h...

AI Technical Summary

Problems solved by technology

(1) The earliest application of steam purging is low in cost and has no corrosive effect on equipment, but the cleaning time is long and the effect is poor

(2) Traditional cleaning of FeS with acidic medium x can effectively transfer the FeS in the device x Clean up, but the cleaning process will also bring a series of problems: first, acid scavenger and FeS x The reaction produces a large amount of toxic H 2 S gas not only threatens the life safety of construction workers, but also causes environmental pollution; second, acidic FeS x The scavenger is highly corrosive to carbon steel equipment. If the equipment is corroded during the construction process (such as remaining in the dead corner of the equipment), it will bury hidden dangers of equipment accidents; third, the cleaning process produces a large amount of acidic wastewater. This creates environmental issues

(3) Alkaline cleaning agent composed of NaOH, surfactant and additives can only remove part of FeS x And waste liquid treatment is difficult

(4) High pH solvent can dissolve FeS quickly and effectively x , but the cost is high, resulting in H 2 S is slowly precipitated, and the waste liquid needs to be treated twice

(5) The multistage oxidant is composed of KMnO 4 , NaClO, K 2 Cr 2 o 7 and other components, can effectively dissolve FeS x , but the operation is unsafe and has side reactions, and the waste liquid contains heavy metal ions such as manganese and chromium

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