Synthesis of high-effective steel corrosion inhibitors in water-oil mixtures

Abstract

The duration of equipment operation depends on the aggressiveness of the media. The corrosion rate is much higher at the elevated concentration of carbon dioxide and hydrogen sulfide. Water, together with the corrosion-active gases dissolved in it, brings the intensive local corrosion damage to steels 20 and St37-2, which are the most common structural materials in the petrochemical and oil and gas extracting industries [2].Mine waters in oil production processes are characterized by high concentrations of mineral salts [3,4]. This results in their high corrosion activity and propensity for IntroductionThe issue related to the chemical resistance of materials and the protection of metals has remained relevant given the permanent corrosion losses by Ukraine's metal fund, which causes significant material losses in various sectors of industry. Corrosion accounts for 40-70 % in the premature destruction of steel structures, which leads to anthropogenic accidents and catastrophes, as well as to the loss of billions of tons of articles. The corrosion-related issues are acute in the chemical, petrochemical, and oil-producing industries [1].

Devising a corrosion inhibitor for steel ST37-2 in a water-oil mixture

“…The synthesis of the AC-1 inhibitor involved diethylenetriamine, which is much more expensive than ethylenediamine, which was used for the synthesis of the AC-2 inhibitor. At the concentration of acetic acid of 0.5 g/dm 3 at a dose of the inhibitor AC-1 of 50 mg/dm 3 the corro-sion rate decreased from 1.5872 to 0.1583 g/(m 2 •h) [18]; when using the AC-2 inhibitor, this indicator decreased to 0.1412 g/(m 2 •h). When using the inhibitor in a water and oil mixture containing 3 g/dm 3 of acetic acid, the corrosion rate decreased from 3.4508 g/(m 2 •h) without the inhibitor to 0.3015 g/(m 2 •h) when using the AC-1 inhibitor in the amount of 50 mg/dm 3 [18] and to 0.2845 g/(m 2 •h) when using the AC-2 inhibitor (Fig.…”

“…Study [18] synthesized alkylimidazolines with the use of sunflower oil and diethylene triamine. However, if we con sider that diethylene triamine price reaches USD 56/kg and the price of pure ethylenediamine is USD 48/kg while the consumption of ethylenediamine to produce 1 kg of imidazoline is 30 % less, it would be advisable to perform the synthesis using ethylenediamine.…”

Evaluation of the efficacy of alkylimidazolines in reducing the corrosion aggressiveness of oil-containing waters

“…The main disadvantage of these inhibitors is their high cost due to high prices for higher carboxylic acids and polyalkylene polyamines. But given the possibility of obtaining imidazolines from available and cheap carboxylic acid derivatives [17], they can be considered quite promising, especially in the oil industry. At this stage, it was important to evaluate the effectiveness of imidazolines as corrosion inhibitors in general, taking into account the effects of mineralization, pH, temperature of water-oil mixtures, their ability to inhibit biocorrosion under anaerobic conditions.…”