Hydrogen Sulfide Corrosion Inhibitors Derived from Amines and Ammonium Salts Containing a Cycloacetal Fragment

In gas compressors operating on natural gas containing hydrogen sulfide, considerable amounts of hydrogen sulfide may get into the lubricating oil, as the hydrogen sulfide is quite oil-soluble. When this happens, the metals and alloys that are in contact with hydrogen sulfide-saturated oils are subject to severe hydrogen sulfide corrosion. The corrosion products, if they enter the oil, render it unsuitable for further service. The most effective means for protecting gas field equipment against hydrogen sulfide corrosion is the use of corrosion inhibitors in the oil. There is considerable urgency in this search for suitable corrosion inhibitors having good compatibility with lube oils. Heterocyclic nitrogen compounds are of much interest. As a rule, they are multifunctional: They manifest antioxidant, anticorrosion, antiwear, and antiscoring properties. In searching for prospective inhibitors of hydrogen sulfide corrosion, we have investigated previously synthesized azoles and sym-trizines containing hindered phenol fragments. In this paper, we present the results of our investigation.

The aggregation properties of hydrophobized polyethyleneimines and their inhibitory activity in hydrogen sulfide and carbon dioxide corrosion of iron were studied. The critical association concentrations, the radii of polymer aggregates formed in aqueous and aqueous alcohol solutions of polyethyleneimines, were determined. It was shown that these polymers at a concentration of 10–25 mg/l display a high inhibiting activity in the reaction of hydrogen sulfide corrosion of iron.

Inhibitors of hydrogen-sulfide corrosion, namely, N-hydroxyethylated ammonium salts of some organic acids, form protective films at Cт3 steel (Z = 95 to 97%). Adsorbed and polymolecular layers of these films were revealed by electron microscopy and x-ray photoelectron spectroscopy. It was shown that the polymolecular layer can compensate for losses of the inhibitor from the sorbed layer.

The inhibiting power of calcium alkylphenol sulfonate obtained by varying the ratios of the initial components was investigated with the optimization method. Using a method from mathematical statistics, the optimum values of the ratio of the basic reagents and conditions of synthesis of effective hydrogen-sulfide metal corrosion inhibitors were found.

This article presents the regularities of reduction of sulfur, nitrate and nitrite ions by sulfur reducing bacteria Desulfuromonas sp., which were isolated from the water of the man-made Yavorivske Lake (Lviv Region, Ukraine), under the influence of potassium dichromate. This bacteria in the process of anaerobic respiration can use and reduce different electron acceptors, such as sulfur, nitrates, nitrites, oxidized forms of heavy metals, in particular, hexavalent chromium. Technogenically altered ecotopes are characterized by complex pollution, so several electron acceptors are available to bacteria at the same time. Strains of microorganisms isolated from such ecotopes are adapted to unfavourable conditions and therefore have high biotechnological potential. The purpose of this work was to investigate the regularities of elemental sulfur, nitrate or nitrite ion usage by sulfidogenic bacteria of Desulfuromonas genus in conditions of simultaneous presence in the medium of another electron acceptor – Cr(VI), to establish the succession of reduction of electron acceptors by strains of these bacteria and to evaluate the efficiency of their possible application in technologies of complex purification of the environment from metal compounds and other inorganic toxicants. Bacteria were grown under anaerobic conditions in Kravtsov-Sorokin medium without SO42– and without Mohr’s salt for 10 days. To study the efficiency of sulfur, nitrate or nitrite ions’ reduction at simultaneous presence in the medium of Cr(VI) bacteria were sown in media with elemental sulfur, NaNO3, NaNO2 or K2Cr2O7 to final S0, NO3–, NO2–or Cr(VI) concentration in the medium of 3.47 (concentration of SO42– in medium of standard composition) or 1.74, 3.47, 5.21, 6.94 and 10.41 mM. Biomass was determined by the turbidimetric method, and the concentrations of nitrate, nitrite, ammonium ions, hydrogen sulfide, Cr(VI), Cr(ІІІ) in cultural liquid were determined spectrophotometrically. It has been established that Cr(VI) inhibits the biomass accumulation and hydrogen sulfide production by bacteria of Desulfuromonas sp. after simultaneous addition into the medium of 3.47 mM S0 and 1.74–10.41 mM Cr(VI). In the medium with the same initial content (3.47 mM) of S0 and Cr(VI) bacteria produced Cr(III) at concentrations 3.3–3.4 times higher than that of hydrogen sulfide. It has been shown that K2Cr2O7 inhibits biomass accumulation, nitrate ions’ reduction and ammonium ions’ production by bacteria after simultaneous addition into the medium of 3.47 mM NO3– and 1.74–10.41 mM Cr(VI) or 1.74–10.41 mM NO3– and 3.47 mM Cr(VI). In the medium with the same initial content (3.47 mM) of NO3– and Cr(VI) bacteria reduced up to 1.2 times more nitrate ions than Cr(VI) with the production of ammonium ions at concentrations the same times higher than those of Cr(III). It has been established that K2Cr2O7 inhibits biomass accumulation, nitrite ions’ reduction and ammonium ions’ production by bacteria after simultaneous addition into the medium of 3.47 mM NO2– and 1.74–10.41 mM Cr(VI) or 1.74–10.41 mM NO2– and 3.47 mM Cr(VI). In the medium with the same initial content of (3.47 mM) NO2– and Cr(VI) the reduction of Cr(VI) by bacteria was only slightly, up to 1.1 times, lower than the reduction of nitrite ions, almost the same concentrations of trivalent chromium and ammonium ions were detected in the cultural liquid. The processes of nitrate and nitride reduction carried out by bacteria of Desulfuromonas genus were revealed to be less sensitive to the negative influence of sodium dichromate, as compared with the process of sulfur reduction, because in the media with the same initial content (3.47 mM) of NO3– or NO2– and Cr(VI) bacteria produced 1.1–1.2 times more NH4+ than Cr(III), but in the medium with the same initial content (3.47 mM) of S0 and Cr(VI) ) bacteria produced over than three times more Cr(III) than hydrogen sulfide. Our data allow us to conclude that bacteria of Desulfuromonas genus, the investigated strains of which are adapted to high concentrations (up to 10.41 mM) of inorganic toxicants, play an important role in the geochemical cycles of sulfur, nitrogen and chromium in aquatic environments that have been under anthropogenic influence.

The results of gravimetric and potentiostatic studies of pyridinium salts, derived from alkenylphenols, as inhibitors of hydrogen sulfide corrosion of steel St 3 in aqueous saline and hydrocarbon systems and testing the salts for bactericidal activity against sulfate-reducing bacteria (SRB) are reported. It has been found that the test compounds with a concentration of 50–150 mg/L slow down the cathodic and anodic reactions and significantly increase the polarization resistance (Rp) of St 3. The best protective properties have been shown by 1-(2-propenylphenoxytetramethylene)-N-pyridinium bromide (III) and 1-(2-allylphenoxytetramethylene)-N-pyridinium bromide (VI): the corrosion protection by III and VI is respectively 87 and 83% at a concentration of 50 mg/L or 96 and 93% at a concentration of 150 mg/L. The pyridinium salts synthesized in this study also exhibit bactericidal activity in a concentration of 50–200 mg/L. High bactericidal properties have been found for 1-(2-propenylphenoxytetramethylene)-N-pyridinium bromide. The SRB growth inhibition at its concentration of 50 or 75 mg/L is 75 or 100%, respectively.

Inhibition of hydrogen sulfide corrosion of steel in gas phase by tributylamine

The chemical reactions in the silent electric discharge were studied when hydrogen reacted on the following inorganic solid substances. (1) Cupric nitrate. Reaction products:—ammonium salt, copper oxide, metallic copper, nitrite, nitrogen peroxide, nitric oxide, and ammonia. (2) Zirconium nitrate. Reaction products:—ammonium salt, zirconium oxide, nitrite, nitrogen peroxide, and nitric oxide. (3) Thallous nitrate. Reaction products:—nitrite, thallous hydroxide, metallic thallium, nitrogen peroxide, and ammonia gas. (4) Uranyl nitrate. Reaction products:—ammonium salt, uranous salt, uranium hydroxide, nitrite, and nitrogen peroxide. (5) Ferric nitrate. Reaction products:—ammonium salt, ferric hydroxide, nitrite, nitrogen peroxide, and nitric oxide. (6) Chromic nitrate. Reaction products:—ammonium salt, chromium hydroxide, and nitrite. (7) Calcium sulphite. Reaction products:—Calcium sulphide, calcium hydroxide, and hydrogen sulphide. (8) Sodium sulphite. Reaction products:—Sodium hydroxide, and hydrogen sulphide. The writer wishes to express his appreciation of a grant from the Imperial Academy towards the expenses of this research.

Aliphatic tertiary diamine (ATD) was synthesized and tested by gravimetric and electrochemical methods as a film-forming inhibitor of hydrogen sulfide corrosion. Both H2S-induced general corrosion in the vapor (80°C) and liquid (20 ± 2°C) phases and hydrogenation are inhibited by ATD more effectively than by aliphatic tertiary amines and commercial corrosion inhibitors. The data obtained were confirmed by comparative autoclave tests simulating the operating conditions of gas mains. Aliphatic tertiary diamine causes no emulsification or foaming and meets requirements imposed by gas industry on the protective and technological properties of film-forming inhibitors of hydrogen corrosion.

The synthesized Schiff bases effectively protect steel in hydrogen sulfide media. Different primary amines were used as the starting reagents to find out how the protection effect of azomethines depends on their nature. It was shown that the higher the electron-donating properties (in terms of normal Wepster constants σH) of substituents in benzaldehyde the better the inhibition of steel corrosion. IPKhAN-62, a new water-soluble mixed-type inhibitor of hydrogen sulfide corrosion, was found to be highly effective in corrosion tests and have considerable aftereffect.

Qualitative criteria for the universalism of hydrogen sulfide and carbon dioxide corrosion inhibitors and their quantitative indices for the corrosion of carbon steel are proposed. They include the maximum value of the total corrosion rate in the presence of H2S and CO2 and with simultaneous limitation of the concentration of the inhibitors themselves. The criteria define a minimum reduction in hydrogenation of steel, suppression of hydrogen diffusion into the metal, contain requirements for the bactericidal ability of inhibitors by limiting the number of cells of sulfate-reducing bacteria and producing hydrogen sulfide, and the requirements for their biodegradability. It is shown that a number of domestic inhibitors of hydrogen sulfide and carbon dioxide corrosion of the new generation of the INKORGAZ series fully satisfy the proposed criteria for universalism.

Substituted imidazolines are one of the most common and effective surface-acting metal corrosion inhibitors. The main tasks of today are to reduce their cost and increase their hydrolytic stability, which is achieved through a targeted choice of the nature and structure of long-chain carboxylic acids in the synthesis of imidazolines. Another way to reduce the cost of producing corrosion inhibitors based on aliphatic ethylenediamines is to use imidazoline precursors – amidoamines and ammonium salts - to protect against corrosion, the production of which is much less energy-consuming.The synthesis of active substances of carbon steel corrosion inhibitors in the reaction of diamines with fatty acids of tall oil was carried out. It is shown that depending on the temperature of the reaction and the introduction of the catalyst – polycationite CU-2-8 - it is possible to selectively obtain derivatives of imidazolines, amidoamines, and ammonium salts, which are capable of inhibiting carbon dioxide corrosion of steel in mineralized water at 60 °C with a degree of protection from 85 % to 91 %. It is noted that the protective effect of amidoamines and ammonium salts is practically not inferior to the action of imidazolines.

Compositions of amide synthesized based on oleic acid and aminoethylethanolamine (AEEA) with cis-1-((4-(-(benzoyloxymethyl)-1,3-dioxolan-2-yl) methyl)-1H-benzo[d][1,2,3]triazol-1-ium acetate synthesized based on benzotriazole were prepared (Reag – A, B, C, D), and their properties against hydrogen sulfide and microbiological corrosion were studied in various concentrations. It has been determined that the ratio of the components contained in the Reag-C is optimum since the reagent completely kills bacteria and shows 95.2% inhibition efficiency against hydrogen sulfide corrosion

In the process of anaerobic respiration, sulfate reducing bacteria, besides sulfates, can use other electron acceptors: nitrates, nitrites, oxidized forms of heavy metals, in particular, hexavalent chromium, which are harmful for organisms. Selection of pollutant-resistant stains of this kind of bacteria isolated from technogenically altered ecotopes, capable of reductive transformation of various nature pollutants, is an especially relevant task for the creation of new effective remediation biotechnologies. The purpose of this work was to investigate the regularities of usage of sulfate, nitrate or nitrite ions by bacteria of the Desulfovibrio genus, isolated from Yavorivske Lake, at conditions of simultaneous presence in the medium of another electron acceptor – Cr(VI), to establish a succession of electron acceptors’ reduction by investigated sulfidogenic bacteria and to evaluate the efficiency of their possible application in technologies of complex purification of the environment from metal, sulfur and nitrogen compounds. Bacteria were grown under anaerobic conditions for 10 days in Kravtsov-Sorokin medium without Mohr’s salt. To study the efficiency of sulfate, nitrate, or nitrite ions’ reduction at simultaneous presence in the medium of Cr(VI), bacteria were sown in media with Na2SO4×10H2O, NaNO3, NaNO2 or K2Cr2O7 to final SO42–, NO3–, NO2– or Cr(VI) concentration in the medium of 3.47 (concentration of SO42– in medium of standard composition) or 1.74, 3.47, 5.21, 6.94, 10.41 mM. Biomass was determined turbidimetrically, and the concentrations of sulfate, nitrate, nitrite, ammonium ions, hydrogen sulfide, Cr(VI), Cr(ІІІ) in cultural liquid were determined by spectrophotometric method. It has been established that Cr(VI) inhibits the biomass accumulation, sulfate ions’ reduction and hydrogen sulfide production by Desulfovibrio sp. after simultaneous introduction into the medium of 3.47 mM SO42– and 1.74–10.41 mM Cr(VI). In the medium with the same initial content (3.47 mM) of SO42– and Cr(VI), bacteria reduced 2.1–2.3 times more Cr(VI) than sulfate ions with Cr(III) production at concentrations up to 2.2 times higher than hydrogen sulfide. It has been shown that K2Cr2O7 inhibits the biomass accumulation, the nitrate ions reduction and the ammonium ions production by bacteria after simultaneous addition into the medium of 3.47 mM NO3– and 1.74–10.41 mM Cr(VI) or 1.74–10.41 mM NO3– and 3.47 mM Cr(VI). In the medium with the same initial content (3.47 mM) of NO3– and Cr(VI) bacteria reduced 1.1–1.3 times more nitrate ions than Cr(VI) with the production of ammonium ions at concentrations up to 1.3 times higher than that of Cr(III). It has been established that K2Cr2O7 inhibits the biomass accumulation, the nitrite ions’ reduction and the ammonium ions’ production by bacteria after simultaneous addition into the medium of 3.47 mM NO2– and 1.74–10.41 mM Cr(VI) or 1.74–10.41 mM NO2– and 3.47 mM Cr(VI). In the medium with the same initial content (3.47 mM) NO2– and Cr(VI) the reduction of Cr(VI) by bacteria practically did not differ from the reduction of nitrite ions (was only slightly lower – up to 1.1 times), almost the same concentrations of trivalent chromium and ammonium ions in the cultural liquid were detected. The processes of nitrate and nitride reduction, carried out by bacteria of Desulfovibrio genus, were revealed to be less sensitive to the negative influence of sodium dichromate, as compared with the process of sulfate ions’ reduction, which in the medium with 3.47 mM SO42– and 1.74–10.41 mM Cr(VІ) decreased by 3.2–4.6 times as compared with this process in the medium with only Na2SO4×10H2O. The investigated strains of bacteria are adapted to high concentrations of toxic pollutants (up to 10.41 mM) and therefore are promising for application in technologies of complex environment purification from hexavalent chromium, sulfur and nitrogen compounds.

N-Alkenylammonium chlorides were synthesized from diethylamine, 4-chloropent-2-ene, and a mixture of 2-methyl-3-chlorobut-1-ene and 3-methyl-3-chlorobut-1-ene. The reaction conditions were optimized. The structure of the products was proved and the main physicochemical characteristics of the synthesized compounds were determined. The synthesized quaternary ammonium salts were tested for bactericidal activity towards corrosion-active microorganisms.