Sulfide Corrosion Research Articles

Characteristics of hydrogen sulfide formation in pulverized coal combustion

Low excess air combustion and two-stage combustion are currently being attempted as a means of reducing NOx emission from the boiler in pulverized coal-fired power plants. However, a strong reducing atmosphere is formed in the region between burners and air ports in the case of two-stage combustion. This atmosphere promotes the formation of hydrogen sulfide (H2S), which causes sulfidation corrosion at the boiler wall. The control of H2S formation and the prevention of corrosion are important in power plants. In this study, the characteristics of H2S formation in two-stage combustion were investigated using a test furnace for pulverized coal combustion. H2S was formed in the case of H2 coexistence. The H2S concentration was affected by the fuel ratio and the sulfur content in coal. The H2S concentration is very low below a H2 concentration of about 2%, above which the H2S concentration has a strong correlation with that of H2. Furthermore, it was found that after the release of sulfur has finished, H2S and SO2 reach equilibrium concentrations in accordance with the equation SO2+3H2=H2S+2H2O.

Review of Wastewater Sulfate Concentration Impacts on Hydrogen Sulfide Odor and Corrosion in Wastewater Collection Systems

Review of Wastewater Sulfate Concentration Impacts on Hydrogen Sulfide Odor and Corrosion in Wastewater Collection Systems

Inhibition of hydrogen sulfide corrosion of steel by volatile amines

The protective effect of amines on steel corrosion under simulated conditions of gas condensate fields are studied. It is shown that primary amines are less effective than secondary and tertiary ones in terms of steel protection, especially in vapor phase. The authors also studied the impact of

Research on Corrosion of Well-Bore Tube and Anticorrosive Measure of Tazhong-1 Gas Field

Natural gas of Tazhong-1 gas field contains 7.7% carbon dioxide and 2.31% hydrogen sulfide, and produced water salinity is up to 140000mg/L,the well-bore tube has seriously potential corrosion destructive with natural gas being exploited. Based on the corrosion type partition of down-hole tube for eighteen production wells of Tazhong-1 gas field, P110,P110S and P110SS corrosion behavior were investigated under the conditions of simulated formation water containing carbon dioxide or hydrogen sulfide/carbon dioxide, and corrosion inhibitors were chosen to meet need of anticorrosion of Tazhong-1 gas field. The results show that fifteen wells in eighteen production wells belong to hydrogen sulfide corrosion of both hydrogen sulfide and carbon dioxide influence. Other wells are singular carbon dioxide corrosion. The most severe corrosion of three types of down-hole tubes all occurs at 90°C in both corrosion media, and their corrosion resistance order is respectively P110>P110S>P110SS and P110S>P110SS>P110 under the conditions of simulated formation water containing carbon dioxide or hydrogen sulfide and carbon dioxide. The selected anti-temperature corrosion inhibitors (YU-1、YU-4) can control the corrosion rate of three types of down-hole tubular goods within 0.076mm/a in simulated formation water media with carbon dioxide (PCO2=0.08～4.64MPa) or hydrogen sulfide and carbon dioxide (PH2S/Pco2=1.3/4.64Mpa) while added amount of the inhibitor is 120～300mg/L or 200mg/L. All of these provide technical support for safe and fast development of Tazhong-1 gas field.

Fe-Si Thermal Spray Coating for Fire Side Corrosion and Erosion Protection in Coal-Fired Boiler

Fe-Si intermetallic thermal spray powders have been developed for sulfidation corrosion and erosion protection for furnace walls in pulverized coal fired boiler. In this paper, evaluation of corrosion and erosion resistance of developed coatings was performed. The corrosion test results showed that the developed coatings almost equal corrosion resistance to conventional corrosion resistant coatings under the low NOX boiler condition. Erosion test results also indicated that Fe-20Si-1B using atmospheric plasma spraying showed higher erosion resistance than the conventional coatings.

Synthesis of bactericides and inhibitors of hydrogen sulfide corrosion from diethylamine and piperylene and isoprene hydrochlorides

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.

Anticorrosive effects and antimicrobial properties of alkyldimethyl(hydroxyalkyl)ammonium bromides

Quaternary ammonium compounds containing the hydroxyalkyl moiety in the head group have been synthesized. These compounds exhibit a micelle-forming ability, high anticorrosive activity, and antimicrobial action. The compounds of the formula R(CH3)2N+(CH2CH2CH2OH)Br− with R = C14H29-C18H37 are characterized by a protective effect higher than 90–99% at 10 mg/l with respect to hydrogen sulfide corrosion, inhibiting properties against carbon dioxide corrosion (84–98% at 10–25 mg/l), and bactericidal action on sulfate-reducing bacteria (10–50 mg/l).

Летучие амины – эффективные ингибиторы сероводородной коррозии стали

Летучие амины – эффективные ингибиторы сероводородной коррозии стали

Fat, oil and grease - Sewer contamination prevention strategies and double-dosage concept for fat traps and pressure mains

Disposal of fat, oil and grease (FOG) in sewer systems cause blockages, fatal errors of pumping stations, increased maintenance, odours, hydrogen sulphide (H2S) emissions and corrosion. Hence, solutions to prevent FOG disposals are desirable. Challenges are prevention of FOG contamination of sewer systems and removal of FOG disposals. A survey and lab as well as full scale tests were performed. In the first place fat traps and grease inceptors should be installed to prevent FOG contamination what is documented as being very effective. A case study shows that the operation of fat traps may indeed produce further problems, especially H2S emissions, what demands an additional treatment. Removal of FOG disposals can be handled by applying enzymes to the affected sewer network. It was found that enzymes are preferable towards surfactants to remove FOG disposals. It appears to be a solution to have one dosing site that is equipped with separately controlled dosing pumps for conditioners for H2S removal as well as FOG removal.

Assessment of the electrochemical corrosion properties and environmentally induced cracking of an A106 Gr B steel pipe weld in a NaCl solution saturated with H2S gas

In the area of heavy construction, welding processes are vital in the production and maintenance of pipelines and power plants. The fusion welding process generates formidable welding residual stress and metallurgical change, which together increase the crack driving force and reduce the resistance against brittle fracturing and environmental fracturing. This is a serious problem with many alloys, and it also arises in A106 Gr B steel pipes. This type of piping, which is used in petrochemical and heavy chemical plants, either degrades due to the corrosive environment, e.g., those containing chlorides and sulfides, and/or become damaged during service due to various corrosion damage mechanisms. Thus, in this study, after numerical and experimental analyses of the welding residual stress of a multi-pass welded A106 Gr B steel pipe weld, the electrochemical corrosion properties and environmentally induced cracking of an A106 Gr B steel pipe weld were assessed in a 5.0 wt.% NaCl solution that was saturated with H2S gas at room temperature on the basis of NACE TM 0177-90. In terms of sulfide stress corrosion cracking (SSCC) and sulfide corrosion fatigue (SCF), the low SSCC limit of smooth specimens, σSSCCsmooth, and the SCF limit, ΔσSCF, were 46 % and 32 % (160 MPa) of the ultimate tensile strength (502 MPa) of an A106 Gr B steel pipe weld, respectively. Further, (Δσres)SCF was assessed under 75 MPa, which is 15 % of the tensile strength.

Analysis and Research on the Cause of Tanker Contaminating Jet Fuel

Through a lot of research on the issue that qualified jet fuel became unqualified jet fuel after tanker transportation and a period of storage. By X-ray photoelectron spectroscopy surface analysis of corroded silver strip and silver strip corrosion test, doctor test, determination of mercaptan sulfur, analysis of sulfur and nitrogen content, test of pickling and alkaline wash and laundering, the mercury wash test and silver nitrate experiments of polluted jet fuel, indicated that silver corrosion resulted from sulfide corrosion, H2S, SO2, SO3, sulfuric acid, acid esters, and other corrosive sulfides were not contained in polluted jet fuel, the corrosive substance in jet fuel was sulfur. The tank inner surface of polluted jet fuel was determined according to GB/T14265-93, the sulfur content in the rust of the tanker inner surface was 1.05% by carbon and sulfur analyzer. Adding the rust into qualified jet fuel, the external situation of tanker transportation was simulated, silver strip corrosion level exceeded 3, which demonstrated that elemental sulfur in the rust dissolved in jet fuel slowly to result in unqualified silver strip corrosion.

Sulfidic corrosion in refineries – a review

Sulfidic corrosion of steels in refineries is a prevalent phenomenon that occurs in oil containing sulfur species between 230°C and 425°C. There are several internal and external variables controlling the occurrence of sulfidic corrosion. The most important external factors are temperature, concentration and type of sulfur species, and presence of naphthenic acid. The most important internal or metallurgical factor to control sulfidic corrosion is the amount of chromium in the steel. The refinery industry relies today in a vast industrial experience on the variables affecting sulfidic corrosion but very little is known on the basic mechanism of attack. There is ample room for research and the basic understanding of this phenomenon.

Optimization of synthesis of a sulfonate hydrogen sulfide corrosion inhibitor

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.

Experiment Study on Safety Evaluation of L245A-Pipe Steel in Wet H<sub>2</sub>S Environment

As Pipeline in Wet H2S environment must consider its anti-hydrogen-induced cracking (HIC) and sulfide stress corrosion cracking (SSCC) performance, in this paper, to ensure L245A-pipe mechanical properties qualified under the premise, according to NACE TM 0284-2003 and NACE TM 0177-2005 standard conducted a test evaluation in Wet H2S in the context of anti-hydrogen-induced cracking performance (HIC) and sulfide stress corrosion cracking resistance (SSCC) and came L245A-pipe in standard Wet H2S environment didn’t produce hydrogen-induced cracking, occurred sulfide stress corrosion cracking, the design conditions and working conditions are no stress corrosion cracking conclusions. And make recommendations on the safe operation in Wet H2S.

High Temperature Corrosion of Evaporator Tubes with Thermal Sprayed Coatings

Degradation examinations of outer surface of low-emission steam boiler evaporator tubes are presented in the paper. Metallographic evaluation of scale morphology as well as determination of chemical composition of micro sites and distribution of elements on cross-sections is reported. Water-wall tubes were exposed in steam boiler for up to two years period. Common tubes produced from 16Mo3 steel suffered sulphide and molten salts corrosions. Thermal sprayed tubes with the single layer of 70%Ni 30%Cr alloy demonstrate better corrosion resistance, but become susceptible to sulphide corrosion due to presence of internal voids and cracks. Double layer Al2O3/Ni-30Cr coatings withstood corrosion attack for more than one year of operation, and then failed due to internal heterogeneity and crack generation.

Inhibited lubricants for protecting gas-carrier and industrial equipment from corrosion

It was shown that use of inhibited lubricants is an effective method of protecting gas commercial and carrier equipment from corrosion, particularly hydrogen sulfide corrosion. A new inhibited turbine oil, Tp-32R, was developed; it differs from the widely used Tp22s turbine oil due to the higher protective and antiwear properties. The new oil underwent classification tests and tests for compliance with the requirements of Gazprom STO.

Sulfidation kinetics of industrial steels in a refinery crude oil at 300 °C: reactivity at the nanometer scale

AbstractHigh temperature sulfidic corrosion has caused safety and reliability issues in refinery units for decades. The objective of the work was to investigate the kinetics of sulfidation under refinery conditions and to characterize, at the nanometer scale, the sulfide layers formed on different steels. The experiments were performed in an autoclave filled with a refinery high‐sulfur crude oil at 300 °C on XC18 carbon steel (Fe–0.18%C), P5 alloy steel (Fe–5% Cr–0.5%Mo) and 304L stainless steel (Fe–18% Cr–8%Ni). The duration of the test ranged from a few hours to a few days.The combination of X‐ray diffraction and transmission electronic microscopy showed the presence of pyrrhotite (Fe1−xS) on XC18, P5 and 304L samples. For all alloys, the S 2p core level decomposition (X‐ray photoelectron spectroscopy) proved the presence of five sulfur species on the surface: sulfide (main species), disulfide, elemental sulfur, sulfite and sulfate. On 304L, the presence of chromium oxide and nickel sulfide was revealed by XPS, whereas chromium sulfide was hardly detected.The macroscopic kinetics of sulfidation was followed by mass loss. The results showed that a parabolic law can fit the kinetics of sulfidation of XC18 and P5 steels. The kinetics of sulfidation of the adherent sulfide layer formed on 304L steel, determined from XPS measurements, follows a logarithmic law. Copyright © 2010 John Wiley & Sons, Ltd.

Assessment of the crack growth characteristics at the low corrosion fatigue limit of an A106 Gr b steel pipe weld

In the area of heavy construction, welding processes are vital in the production and maintenance of pipelines and power plants. The fusion welding process generates formidable welding residual stresses and metallurgical change, which increase the crack driving force and reduce the resistance of brittle fracture as well as environmental fracture. This is a serious problem with many alloys as well as A106 Gr B steel pipe. This pipe, used in petrochemical and heavy chemical plants, either degrades due to corrosive environments, e.g., chlorides and sulfides, and/or becomes damaged during service due to the various corrosion damage mechanisms. Thus, in this study, the sulfide corrosion fatigue strength of multi-pass welded A106 Gr B steel pipe was evaluated in a 5.0 wt.% NaCl solution that was saturated with H2S gas at room temperature on the basis of NACE TM 0177-90. The crack growth characteristics of the welded pipe were then assessed at the low limit of sulfide corrosion fatigue strength, which was previously obtained from the sulfide corrosion fatigue (SCF) tests. From the results, in terms of the SCF, all the specimens failed at the heat-affected zone, where a high welding residual stress distributes. It was found that the fatigue crack grew at the low corrosion fatigue limit (σSCFun-notched), which was 32 % (160MPa) of the ultimate tensile strength (502MPa) of the welded specimens.

Analysis of copper corrosion in compacted bentonite clay as a function of clay density and growth conditions for sulfate‐reducing bacteria

To investigate the relationships between sulfate-reducing bacteria (SRB), growth conditions, bentonite densities and copper sulfide generation under circumstances relevant to underground, high-level radioactive waste repositories. Experiments took place 450 m underground, connected under in situ pressure to groundwater containing SRB. The microbial reduction of sulfate to sulfide and subsequent corrosion of copper test plates buried in compacted bentonite were analysed using radioactive sulfur (35SO4(2-)) as tracer. Mass distribution of copper sulfide on the plates indicated a diffusive process. The relationship between average diffusion coefficients (Ds) and tested density (rho) was linear. Ds (m2 s(-1))=-0.004xrho (kg m(-3))+8.2, decreasing by 0.2 Ds units per 50 kg m(-3) increase in density, from 1.2x10(-11) m2 s(-1) at 1750 kg m(-3) to 0.2x10(-11) m2 s(-1) at 2000 kg m(-3). It is possible that sulfide corrosion of waste canisters in future radioactive waste repositories depends mainly on sulfide concentration at the boundary between groundwater and the buffer, which in turn depends on SRB growth conditions (e.g., sulfate accessibility, carbon availability and electron donors) and geochemical parameters (e.g., presence of ferrous iron, which immobilizes sulfide). Maintaining high bentonite density is also important in mitigating canister corrosion. The sulfide diffusion coefficients can be used in safety calculations regarding waste canister corrosion. The work supports findings that microbial activity in compacted bentonite will be restricted. The study emphasizes the importance of growth conditions for sulfate reduction at the groundwater boundary of the bentonite buffer and linked sulfide production.

Inhibition of hydrogen transport through Pd and Pd 47Cu 53 membranes by H 2S at 350 °C

In pure H 2 gas, hydrogen fluxes through pure Pd and Pd 47Cu 53 (mol%) foils at 350 °C are similar. In the presence of 1000 ppm H 2S in H 2, the hydrogen fluxes through both foils are substantially reduced, but with significantly different decay patterns. Six hours after the start of H 2S exposure, the Pd foil remained permeable to hydrogen, with the flux decreasing slowly over time. Analysis of the Pd foil by X-ray diffraction (XRD) and scanning electron microscopy (SEM) reveals that Pd reacts with H 2S to form a palladium sulfide corrosion product, Pd 4S, which is about 6.6 μm thick. These observations are consistent with the slow growth of a low-permeability, but catalytically active, sulfide corrosion layer on the Pd surface. In contrast, the hydrogen flux through the Pd 47Cu 53 foil is undetectable within 5 min of the start of H 2S exposure. XPS depth profiling of the Pd 47Cu 53 foil reveals that sulfur penetrates only ∼3 nm into the Pd 47Cu 53 surface. Rapid formation of a Pd–Cu–S terminal layer, which is either inactive for hydrogen dissociation or impermeable to hydrogen atoms, is responsible for the deactivation of the Pd 47Cu 53 alloy membrane in H 2S at 350 °C.