Biodegradation of corrosion inhibitors and their influence on petroleum product pipeline

In Situ Investigation of Under-Deposit Microbial Corrosion and its Inhibition Using a Multi-Electrode Array System

Carbon steel pipelines used in the oil and gas industry can be susceptible to the combined presence of deposits and microorganisms, which can result in a complex phenomenon, recently termed under-deposit microbial corrosion (UDMC). UDMC and its inhibition in CO₂ ambiance were investigated in real-time using a multi-electrode array (MEA) system and surface profilometry analysis. Maps from corrosion rates, galvanic currents, and corrosion potentials recorded at each microelectrode allowed the visualization of local corrosion events on the steel surface. A marine bacterium Enterobacter roggenkampii, an iron-oxidizing, nitrate-reducing microorganism, generated iron deposits on the surface that resulted in pitting corrosion under anaerobic conditions. Areas under deposits displayed anodic behavior, more negative potentials, higher corrosion rates, and pitting compared to areas outside deposits. In the presence of the organic film-forming corrosion inhibitor, 2-Mercaptopyrimidine, the marine bacterium induced local breakdown of the protective inhibitor film and subsequent pitting corrosion of carbon steel. The ability of the MEA system to locally measure self-corrosion processes, galvanic effects and, corrosion potentials across the surface demonstrated its suitability to detect, evaluate and monitor the UDMC process as well as the efficiency of corrosion inhibitors to prevent this corrosion phenomenon. This research highlights the importance of incorporating the microbial component to corrosion inhibitors evaluation to ensure chemical effectiveness in the likely scenario of deposit formation and microbial contamination in oil and gas production equipment.

Improving the sustainability of biodiesel by using imidazolium-based ionic liquid

Corrosion of biodiesel-filled fuel tanks has become a major problem in the use of biodiesel as a new green energy source. The ionic liquid 1-Hexyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ was used to control corrosion of C-steel in non-edible biodiesel to resolve this problem. The anti-corrosion and antioxidant properties of the [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ were characterized using weight loss, electrochemical impedance spectroscopy, total acid number measurements beside SEM and EDX analysis. The findings show that [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ plays an important role in preventing C-steel corrosion in biodiesel with an efficiency close to 99 percent. The adsorption capability and antioxidant properties of [C₁₀H₁₉N₂]⁺[C₂F₆NO₄S₂]⁻ are the major contributors to the ionic liquid's anti-corrosion properties. We anticipate that this work will help to sustainable expand the use of biodiesel as a renewable energy source.

Bacillus megaterium-induced biocorrosion on mild steel and the effect of Artemisia pallens methanolic extract as a natural corrosion inhibitor

Methanolic extract of Artemisia pallens (MEAP) (Asteraceae) was explored as greenbiocorrosion inhibitor for mild steel 1010 in 1.5% sodium chloride environment. Bacillus megaterium SKR7 induces the development of biofilm on the metal surface and forms the pitting corrosion. MEAP was showed (25 ppm) optimum inhibition effect of biocorrosion and further corrosion rate was highly reduced (0.3335 mm/year) than the control system (0.009 mm/year). The electrochemical study has supported the results with a higher value of total resistance (34 Ω cm²) when compared to control systems. It reveals the formation of a protective layer on the metal surface and reduces the adsorption of biofilm. This was due to the antimicrobial effect of MEAP. Overall, the results recognized that MEAP used as a green corrosion inhibitor for MS 1010 with 83% inhibition efficiency.

Effects of palm biodiesel and blends of biodiesel with organic acids on metals

This paper presents the corrosion behavior studies of five metallic materials used in auto part manufacturing exposed to pure palm biodiesel (B100) and palm biodiesel mixed with acidic species commonly found in biodiesel. Samples of AISI-SAE 1005 carbon steel, AISI-SAE 304 stainless steel, tin, aluminum and copper were exposed to a temperature of 45 °C for 12 months. The highest corrosion rates were present in totally immersed copper (B100-acetic acid blend) and in carbon steel (B100-oleic acid blend). The most corrosive blends for the metallic materials were B100-linoleic acid, B100-oleic acid and B100-acetic acid. The efficacy of two corrosion inhibitors, ethylenediamine (EDA) and tert-butylamine (TBA) increased as a function of exposure time. The characterization tests allowed the detection of different species, in the products of steel corrosion, associated with, lepidocrocite, ferrihydrite, magnetite, and some iron carbonates. In turn, cuprite, malachite, azurite, and some copper carbonates were found on the copper samples. Such corrosion products formed protective layers on the surface of the metals, which is reflected in a decrease in corrosion rates over time.

Sustainability of renewable fuel infrastructure: a screening LCA case study of anticorrosive graphene oxide epoxy liners in steel tanks for the storage of biodiesel and its blends

Biodiesel is a widely used fuel that meets the renewable fuel standards developed under the Energy Policy Act of 2005. However, biodiesel is known to pose a series of abiotic and biotic corrosion risks to storage tanks. A typical practice (incumbent system) used to protect the tanks from these risks include (i) coating the interior surface of the tank with a solvent-free epoxy (SFE) liner, and (ii) adding a biocide to the tank. Herein, we present a screening-level life-cycle assessment study to compare the environmental performance of a graphene oxide (GO)-epoxy (GOE) liner with the incumbent system. TRACI was used as an impact assessment tool to model the midpoint environmental impacts in ten categories: global warming potential (GWP, kg CO₂ eq.); acidification potential (AP, kg SO₂ eq.); potential human health damage impacts due to carcinogens (HH-CP, CTU_h) and non-carcinogens (HH-NCP, CTU_h); potential respiratory effects (REP, kg PM_2.5 eq.); eutrophication potential (EP, kg N eq.); ozone depletion potential (ODP kg CFC-11 eq.); ecotoxicity potential (ETXP, CTU_e); smog formation potential (SFP kg O₃ eq.) and fossil fuel depletion potential (FFDP MJ surplus). The equivalent functional unit of the LCA study was designed to protect 30 m² of the interior surface (unalloyed steel sheet) of a 10 000 liter biodiesel tank against abiotic and biotic corrosion during its service life of 20 years. Overall, this LCA study highlights the improved environmental performance for the GOE liner compared to the incumbent system, whereby the GOE liner showed 91% lower impacts in ODP impact category, 59% smaller in REP, 62% smaller in AP, 67-69% smaller in GWP and HH-CP, 72-76% smaller in EP, SFP, and FFDP, and 81-83% smaller ETXP and HH-NCP category results. The scenario analysis study revealed that these potential impacts change by less than 15% when the GOE liners are functionalized with silanized-GO nanosheets or GO-reinforced polyvinyl carbazole to improve the antimicrobial properties. The results from an uncertainty analysis indicated that the impacts for the incumbent system were more sensitive to changes in the key modeling parameters compared to that for the GOE liner system.

Water-soluble Moringa oleifera lectin interferes with growth, survival and cell permeability of corrosive and pathogenic bacteria

AIMS

This work evaluated the antibacterial activity of a water-soluble Moringa oleifera seed lectin (WSMoL) by evaluating its effect on growth, survival and cell permeability of Bacillus sp., Bacillus cereus, Bacillus pumillus, Bacillus megaterium, Micrococcus sp., Pseudomonas sp., Pseudomonas fluorescens, Pseudomonas stutzeri and Serratia marcescens. In addition, the effect of lectin on membrane integrity of most sensitive species was also evaluated. All the tested bacteria are able to cause biocorrosion and some are also responsible for human infections.

METHODS AND RESULTS

WSMoL inhibited the bacterial growth, induced agglutination and promoted the leakage of proteins from cells of all strains. Bactericidal effect was detected against Bacillus sp., B. pumillus, B. megaterium, Ps. fluorescens and Ser. marcescens. The bacteriostatic effect of lectin was evident with only 6 h of incubation. Fluorescence microscopy of Ser. marcescens showed that WSMoL caused loss of cell integrity and indicated an anti-biofilm activity of the lectin.

CONCLUSIONS

WSMoL was active against the bacteria by inhibiting growth and affecting cell permeability. The lectin also interfered with membrane integrity of Ser. marcescens, the most sensitive species.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study indicates that WSMoL was active against bacteria that cause serious problems in both industrial and health sectors. Also, the study contributes for the 'state-of-art' on antibacterial mechanisms of lectins.

Characterization of Corrosive Bacterial Consortia Isolated from Water in a Cooling Tower

An analysis of a culturable corrosive bacterial community in water samples from a cooling tower was performed using traditional cultivation techniques and its identification based on 16S rRNA gene sequence. Seven aerobic bacterial species were identified: Pseudomonas putida ARTYP1, Pseudomonas aeruginosa ARTYP2, Massilia timonae ARTYP3, Massilia albidiflava ARTYP4, Pseudomonas mosselii ARTYP5, Massilia sp. ARTYP6, and Pseudomonas sp. ARTYP7. Although some of these species have commonly been observed and reported in biocorrosion studies, the genus Massilia is identified for the first time in water from a cooling tower. The biocorrosion behaviour of copper metal by the new species Massilia timonae ARTYP3 was selected for further investigation using a weight loss method, as well as electrochemical and surface analysis techniques (SEM, AFM, and FTIR). In contrast with an uninoculated system, thin bacterial biofilms and pitting corrosion were observed on the copper metal surface in the presence of M. timonae. The use of a biocide, bronopol, inhibited the formation of biofilm and pitting corrosion on the copper metal surface.

Molecular analysis of microbial diversity in corrosion samples from energy transmission towers

Microbial diversity in corrosion samples from energy transmission towers was investigated using molecular methods. Ribosomal DNA fragments were used to assemble gene libraries. Sequence analysis indicated 10 bacterial genera within the phyla Proteobacteria, Firmicutes, Actinobacteria and Bacteroidetes. In the two libraries generated from corroded screw-derived samples, the genus Acinetobacter was the most abundant. Acinetobacter and Clostridium spp. dominated, with similar percentages, in the libraries derived from corrosion scrapings. Fungal clones were affiliated with 14 genera belonging to the phyla Ascomycota and Basidiomycota; of these, Capnobotryella and Fellomyces were the most abundant fungi observed. Several of the microorganisms had not previously been associated with biofilms and corrosion, reinforcing the need to use molecular techniques to achieve a more comprehensive assessment of microbial diversity in environmental samples.

Role of Serratia marcescens ACE2 on diesel degradation and its influence on corrosion

A facultative anaerobic species Serratia marcescens ACE2 isolated from the corrosion products of diesel transporting pipeline in North West, India was identified by 16S rDNA sequence analysis. The role of Serratia marcesens ACE2 on biodegradation of diesel and its influence on the corrosion of API 5LX steel has been elucidated. The degrading strain ACE2 is involved in the process of corrosion of steel API 5LX and also utilizes the diesel as an organic source. The quantitative biodegradation efficiency (BE) of diesel was 58%, calculated by gas-chromatography-mass spectrum analysis. On the basis of gas-chromatography-mass spectrum (GC-MS), Fourier Transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD), the involvement of Serratia marcescens on degradation and corrosion has been investigated. This basic study will be useful for the development of new approaches for detection, monitoring and control of microbial corrosion.