Cathodic Protection System Research Articles

Impact assessment of metals realeased by aluminium-based galvanic anode on the physiology of the abalone Haliotis tuberculata in controlled conditions.

To protect metal structures immersed in the sea from corrosion, the galvanic anode cathodic protection system (GACP) is often applied. However, this association leads to continuous oxidation of the galvanic anode and therefore to a release of a metal cocktail in the forms of ions or oxy-hydroxides. Therefore, the main objective of our study was to investigate the toxicity of elements released from the dissolution of an aluminium-based galvanic anode (∼95% Al, ∼5% Zn, <0.1% for In, Cu, Cd, Mn, Fe) on a grazing gastropod, the abalone Haliotis tuberculata. The present study was carried out in complement to other research currently in submission. Gastropods were exposed for 16 weeks (12 weeks of exposure and 4 weeks of decontamination phase) to 6 conditions including a control, 4 concentrations based on total aluminium level (86, 425, 1096 and 3549 µg L-1) and a trophic control, corresponding to abalones placed in non-contaminated natural seawater but fed with contaminated algae. The effects of metals on growth, glycogen levels, brix index of hemolymph, MDA levels in digestive gland and gills, hemocyte phagocytic activity, ROS production, lysosomal system and the progress of gametogenesis were investigated throughout the entire exposure allowing the realization of kinetics. The results revealed that the aluminium-based anode does not seem to have an effect on the health status of the individuals for environmentally realistic concentrations. However, in extreme conditions strong effects were reported on the growth, immune system and reproduction of abalone.

Investigation of the Pipeline Coating Properties Degradation to Increase the Energy Efficiency of the Cathodic Protection Stations

In this paper, it is proposed to investigate the influence of the parameter providing the rate of pipeline coating degradation on the protective length of cathodic protection systems (CPS). Comparison of the calculated values of the pipeline coating resistance with the predicted values is carried out according to the theoretical distribution of the pipeline coating resistance in time. The difference between the practical value of the parameter providing the rate of coating degradation of the considered pipeline section from the predicted one is determined. The dependence of the parameter providing the rate of pipeline coating degradation on the protective length of the CPS has been formed, which makes it possible to reduce the number of cathodic protection stations along the pipeline path at the design stage, and to diminish their energy consumption in the electrochemical protection system from corrosion of oil and gas pipelines.

Bond performance between corroded steel bars and concrete in cathodic protection system with CFRP as anode

Bond performance between corroded steel bars and concrete in cathodic protection system with CFRP as anode

Assessment of the Impressed Current Cathodic Protection system after 4 years operation: Case study of the Saint-Cloud Viaduct (France)

Impressed Current Cathodic Protection (ICCP) is an electrochemical technique widely used, especially for repairing reinforced concrete structures contaminated with chlorides. This paper represents the results of the feedback of the ICCP system implemented on a road bridge, the Viaduct of Saint-Cloud in France. In 2012, a field trial was conducted in order to evaluate the effectiveness and the reliability of an ICCP system with embedded anodes designed for impressed current. The full-scale ICCP system was energized in 2018. Results of the four years monitoring including the variations of the applied current density and the polarization of the various anodic zones are presented. The ICCP data analysis is performed taking into consideration the initial degradation level of the span segments and the presence of prestressed tendons ducts. The electrical resistance of the circuit is influenced by several factors, the most important of which is the temperature. Considerations about the heterogeneity of the concrete resistivity are discussed.

Aluminium-based galvanic anode impacts the photosynthesis of microphytobenthos and supports the bioaccumulation of metals released

Very few studies have looked at the potential biological effects of degradation products of galvanic anodes particularly on primary producers which are central to food webs in marine ecosystems. The galvanic anode cathodic protection system (GACP) is widely used to protect submerged metallic structures from corrosion. Aluminium (Al) and zinc (Zn) are the main constituents of galvanic anodes and are therefore released in the marine environment by oxidation process to form ions or oxy-hydroxides. The main objective of our study was to evaluate the effects of the metals released from an aluminium-based galvanic anode on microphytobenthos performance in term of biofilm growing through the analysis of photosynthetic parameters, the determination of chlorophyll and extracellular polymeric substances (EPS). The bioaccumulation of Al and Zn were measured in the microphytobenthic compartment collected at the surface of polyvinyl chloride (PVC) plates exposed during 13 days to seawaters enriched in different concentrations of metals released from dissolution of one anode. Determination of bioconcentration factors confirmed that the microphytobenthos has incorporated Al. A significative effect was observed on the Chl a concentration for the higher tested concentration ([Al] = 210.1 ± 60.2 µg L − 1; [Zn] = 20.2 ± 1.4 µg L − 1). The seawater exposed to the anode affected the MPB productivity (ETRIImax) with consequences on acclimatation light (Ek), absorption cross section of PSII (σPII), Fv/Fm and NPQ. Regarding the EPS production, the anode degradation presented an impact on high and low molecular weight of both carbohydrates and protein fractions of microphytobenthos suggesting that EPS play an essential role in sequestering metal contaminants to maintain the integrity of the biological membranes and the functionality of the cellular organelles. The accumulation of Al released by GACP in microphytobenthos cells could lead to physiologic problems in photosynthetic organisms.

Synergistic effects of charge transport and trapping in tribomaterials for boosted triboelectric nanogenerators

Improving output performance is a key to develop triboelectric nanogenerator (TENG) applications. Herein, an improved melamine foam (MF) /MXene/Ecoflex@TiO2-TENG (FME@TiO2-TENG) based on the composite dielectric MF/MXene/Ecoflex@TiO2 (FME@TiO2) is developed after comprehensively considering charge generation, transport, trapping, and dissipation. A 3D MF framework with evenly dispersed MXene exhibits strong electronegativity, electrical conductivity, and a formation of a large number of micro-capacitances, which are advantageous for surface charge generation, transfer, and retention in the composite dielectric FME@TiO2. More importantly, dual functions of a TiO2 nanotube array film, i.e., its high dielectric property and electron-trapping ability, are beneficial for output of electrical properties. A cathodic protection system powered by the FME@TiO2-TENG was designed to demonstrate its application potential in electrochemistry. Furthermore, a novel in-situ micro-electrolytic cell observation system using K3[Fe (CN)6] as an indicator was designed to evaluate the cathodic protection effect. The results showed that the FME@TiO2-TENG could be used as an independent power source to provide electrochemical cathodic protection. This study provides a useful guidance for a development of the high-performance TENG composite dielectrics and promotes their practical application in the field of the electrochemical cathodic protection.

Study on the Interference Law of AC Transmission Lines on the Cathodic Protection Potential of Long-Distance Transmission Pipelines

Through inductive coupling, AC transmission lines can generate large amounts of voltage to buried oil and gas pipelines in areas with common corridors, posing a threat to the cathodic protection effect of pipelines. Therefore, this paper investigates the effect of AC transmission lines on the cathodic protection of long-distance pipelines through inductive coupling. COMSOL Multiphysics finite element simulation software is used to calculate the distribution of cathodic protection potential of long-distance pipelines under different voltage levels, parallel spacing, conductor-to-ground height, conductor arrangement and pipeline burial depth for normal operation of AC transmission lines. Comparison and analysis of the AC transmission line on the pipeline cathodic protection potential interference law is conducted. The results show that: 1. AC transmission lines cause serious electromagnetic interference with the pipeline cathodic protection system, which will cause the pipeline cathodic protection potential to shift out of the effective protection area. 2. The maximum value of the induced voltage of the pipeline will appear at the two ends of the pipeline, and the induced voltage of the pipeline in the middle position is 0. 3. The shift of the pipeline cathodic protection potential increases with the increase of voltage level and decreases with the increase of parallel spacing, conductor height and burial depth. The pipeline cathodic protection potential shift is highest when the wires are arranged horizontally and lowest when they are arranged in an umbrella shape.

Electrochemical Evaluation of the Metal-Media Interface of a Calcareous-Formed Al-Base Alloy Immersed in a Synthetic Seawater Solution

Corrosion occurs in any environment where a metallic structure interacts with the surrounding environment, being the marine environment one of the most corrosive environments and therefore the one that deteriorates metals the most. The cathodic protection systems are the fundamental way to protect metallic structures in marine environments being a highly effective method, besides, as a reaction product of the cathodic protection system, calcareous deposits (CaCO3 and Mg (OH)2) are formed on the structures. One type of cathodic protection system is sacrificial anodes, among which Al-based anodes have been widely used. Al-Zn-X (In-Hg-Sn) alloys have shown an optimum performance as sacrificial anodes in seawater, but with a limitation which is the environmental contamination that some of its components can generate. The purpose of the present work of investigation was the variation of the electrochemical behavior of an Al-Zn-Mg alloy with a calcareous deposit. Evaluating this variation by Rp and EIS techniques, getting preliminarily that the formation of calcareous deposits generates a natural protective barrier on the structure of the alloy.

The sealed bionic fishtail-structured TENG based on anticorrosive paint for ocean sensor systems

Triboelectric nanogenerators (TENGs) have attracted considerable research attention because of there ability to collect low-frequency mechanical energy. The sealed bionic fishtail-structured TENG (SBF-TENG) based on anticorrosive paint is presented for the first time in this paper because of its good maneuverability, stability and mechanical characteristics for harvesting blue energy. Meanwhile, the material characteristics of the SBF-TENG are systematically studied and engineered for optimizing triboelectric power generation, collecting the wave energy in the environment. The salinity of the ocean or solution can be sensitively detected by The SBF-TENG through the collection of ocean energy. Furthermore, the service life of metals in the ocean or solution can be increased through the cathodic protection system constructed by the SBF-TENG. This work provides a paradigm of combining TENGs with the biomimetic underwater robot, and it is of great importance for the application of TENGs in the field of metal cathodic protection and ocean sensor systems.

Design of a Printed Circuit Board for Real-time Monitoring and Control of Pipeline’s Cathodic Protection System via IoT and a Cloud Platform

Design of a Printed Circuit Board for Real-time Monitoring and Control of Pipeline’s Cathodic Protection System via IoT and a Cloud Platform

Galvanic corrosion and cathodic protection of re-grouted, post-tensioned (PTd) concrete systems

Grouted post-tensioned (PTd) concrete systems are widely used in long-span segmental bridges with a target service life of 100+ years. However, the usage of inadequate grout materials and grouting practices have resulted in the formation of unwanted air voids in the duct, which in turn led to premature corrosion (say, within about 20 years) of strands and failure of tendons. Also, the re-grouting/repairing of void regions have led to localized corrosion of strands at the interface between the dissimilar base-grout (usually carbonated) and repair-grout. This study aims (i) to quantify the galvanic corrosion at the void region in a PTd system re-grouted with a dissimilar grout and (ii) to develop cathodic protection system to protect PTd anchorage regions. Specimens simulating the re-grouted strand-grout-air (SGA) interface were prepared with prestressing steel wires and cementitious grout. The macro-cell current (galvanic current) between the prestressing steels embedded in carbonated base-grout and repair-grout indicated that galvanic corrosion can be possible at the SGA interface – reducing the long-term structural reliability of re-grouted PTd bridges. In addition, the feasibility of galvanic anode cathodic protection system to protect PTd anchorage regions was assessed. For this, a proof-of-concept study was conducted to validate that a thin layer of grout around the strand will be sufficient for a galvanic anode (connected to the end of the strand at outside the tendon anchorage) to protect the strand portions inside the duct/anchorage.

Enhancement of Interfacial Wettability between Al-Zn Alloy Matrix and MnO2 Decorated with Ni for Effective Cathodic Protection Systems

Substrates made of steel used in coastal applications are regularly exposed to harsh salty environments; as a result, it is essential to adopt reliable strategies for preventing corrosion. Utilization of aluminum rich sacrificial anodes is an efficient anticorrosive technique owing to its high columbic amplitude, low density, inherent negative potential and galvanic economy. In this work, the electrochemical and micro-structural was characterized by catalytic effect of MnO2-Ni on anode activation. MnO2-Ni present in anode matrix results in destroyed passive alumina film and facilitates the galvanic growth on an anode. The anode exhibited active operating potential and high columbic efficiency during prolonged marine exposure studies. High anodic efficacy was performed by fine tuning composites into the metal matrix Al based alloy. The results revealed that the preferential dissolution of intermetallic particles induced effective sacrificial anode action.

Suppression of corrosion on stainless steel 303 with automatic impressed current cathodic protection (a-ICCP) method in simulated seawater

One effective method to slow down metal corrosion rate is the impressed current cathodic protection (ICCP) system. The ICCP system is suitable for coastal applications such as piping systems and offshore structures. In this application, metal surfaces tend to be exposed to seawater. Specific concentrations of seawater can accelerate the occurrence of corrosion of metals, even though they are stainless steel types. This study applied the automatic ICCP system to stainless steel 303. Stainless steel 303 will be immersed in simulated seawater at several concentrations of NaCl (27 ppt, 31 ppt, and 35 ppt). The specimens were immersed in NaCl solution for three weeks or about 504 hours at a constant temperature of 38 °C. After the sample has been soaked, quantitative and qualitative measurements were carried out. Quantitative measures include average weight loss, corrosion rate, and potential value. At the same time, the qualitative measurements include macroscopic, Scanning Electron Microscopy (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS). Based on quantitative measures, it was found that the difference in average weight loss and corrosion rate for each NaCl concentration was not very significant. The difference of each parameter is less than 0.1 % and 0.22 %, respectively. The potential value quickly reaches a steady state at NaCl concentrations of 27 ppt and 31 ppt in less than 10 seconds. The results of the SEM test showed a change in the metal structure. The oxygen (O) content in the metal after the EDS test showed a decrease in this element up to 35 % at a NaCl concentration of 35 ppt. The decrease in oxygen (O) can slow down the corrosion rate in metals when exposed to seawater.

Effects on Growth of Juvenile Abalones Haliotis tuberculata Under Chronic Exposition to Metals Released from the Dissolution of an Aluminium-Based Galvanic Anode

In the marine environment, the galvanic anode cathodic protection system (GACP) undergoes oxidation and releases metals in the forms of ions or oxy-hydroxides into the environment. The objective of the present study was to investigate the toxicity of a cocktail of metals released from the dissolution of an aluminium-based galvanic anode (~ 95% Al, ~ 5% Zn) on the abalone Haliotis tuberculata. Juveniles were exposed for 16weeks (i.e. 12weeks of exposure and 4weeks of decontamination phase) and their growth, intake rate, conversion rate and metallic concentrations were monitored. A total of 6 conditions were tested: a control, 4 concentrations based on Al and a trophic control. Results showed that the mortality reached 57% for individuals exposed to 1125µg L-1 of Al, and the abalone growth significantly decreased for an Al concentration greater than 495µg L-1. At the highest exposure concentration, intake rate measurements revealed that the appetite of abalones was affected, supported by the large increase in the conversion rate which was indicative of a poor feed efficiency. The monitoring of metallic concentrations showed that H. tuberculata strongly bioconcentrated Al relative to zinc. The diet did not appear to be the primary pathway for metal entry. Concentrations that significantly impacted abalone growth and survival during the experiment were higher than those found in natural environment, but the bioconcentration of Al into the tissues of a primary consumer such as abalone may be a potential pathway for Al to enter food webs.

A high-spintronic helix metal-organic chain as a high-output triboelectric nanogenerator material for self-powered anticorrosion

The development of novel and stable metal–organic coordination polymer triboelectric materials is of great significance for the application of micro/nano power sources in self-powered systems. Here we report the example of a high-spintronic helical metal–organic chain (ZUT-9) by using ionic ligand. ZUT-9 has good chemical stability, functional tunability and excellent triboelectric output performance, which is superior to traditional polymer materials. By adjusting the type of metal and increasing the number of spinons in the metal center, the triboelectric behavior can be effectively improved. The good output performance makes ZUT-9 effective in preventing metal corrosion in cathodic protection system. Combined with theoretical calculation and magnetic behavior characterization, the results show that increasing the number of spinon can be an effective way to significantly enhance the electron delocalization effect and promote frictional power generation behavior. This study provides an idea for the research of helical metal–organic chain materials and will promote their application in self-powered electrochemical cathodic protection.

Sacrificial Anode Cathodic Protection System Modelling Using Direct Boundary Element Method

Abstract Cathodic protection system is commonly employed approach for the protection of the metallic infrastructure placed in electrolyte against corrosion. Adequate design of the cathodic protection system requires the determination of electrical potential and current density distribution on the protected object surface that meets the defined criteria. In this paper, the application of the direct boundary element method in conjunction with Newton-Raphson method was considered for the calculation of the electric potential and current density distribution on the surface of the cathodically protected underground object. The considered method was applied on the sacrificial anode cathodic protection system of the underground pipeline. The non-linear boundary conditions of the electrode surfaces of the cathodic protection system are taken into account. The method was used to determine the current density and electric potential distribution on the external wall of the protected pipeline.

Impacts of GIC on the New Zealand Gas Pipeline Network

AbstractGeomagnetically induced currents produced during geomagnetic storms present a potential risk to gas pipeline systems by disturbing the cathodic protection (CP) systems used to protect the pipeline from corrosion. In this study we look at CP monitoring data from a number of sites on the gas pipeline network in the North Island of New Zealand. We focus on variations during geomagnetic storms in three aspects of the CP system: (a) the output voltage of the constant current rectifiers, (b) the potential between the pipe and a Cu/CuSO4 reference cell, and (c) the potential between an installed metal coupon and the reference cell. The industry standard for suitable CP is that the latter potential should lie between −0.85 and −1.2 V when the rectifier is momentarily turned off. Three monitoring sites in particular are identified as showing very large variations in rectifier output voltage during geomagnetic storms, suggesting a possible risk to the system at these sites. Additionally, one of the three sites has coupon potentials which appear to rise above the −0.85 V level. Magnetotelluric impedance data are used to assess how effects at the monitoring sites relate to the magnitude and direction of induced electric fields. It clear that the response at any monitoring site is related to effects on the pipeline network as a whole. We also note the risks of disbonding and hydrogen induced cracking, issues we do not believe have been widely recognized in the research community.

3D Analysis of Pipeline with Cathodic Corrosion Protection

Abstract Natural gas is an indispensable resource for human life. Its transport is usually done through underground pipelines. Due to the environment in which they are placed, the pipelines are subjected to a continuous process of corrosion. This paper aimed a 3D numerical analysis using specialized software (COMSOL Multiphysics) to study several parameters that influence the corrosion of underground pipelines. Starting from real geometric and environmental data, a comparative analysis was performed, considering the pipeline coating (e.g., with HDPE - high- density polyethylene), the placement of the cathode protection electrode, and the soil conductivity near the pipeline. The results confirm the need to cover the pipelines and can be a starting point for choosing the final configuration of the cathodic protection system.

Development of Conductive Mortar for Efficient Sacrificial Anode Cathodic Protection of Reinforced Concrete Structures—Part 1: Laboratory Experiments

This experimental study proposes a conductive mortar to increase the efficiency of the sacrificial anode cathodic protection (SACP) system by decreasing resistivity and maintaining it for a long time. The resistivity characteristics of the mortar that contained electrically conductive admixtures and/or chemical agents were evaluated by the Brunauer–Emmett–Teller (BET) method and resistivity measurements. The conductive mortar with activated carbon and sodium hydroxide had the lowest resistivity. The SACP system was then designed to evaluate the cathodic protection (CP) performance with the proposed activated-carbon-based conductive mortar. The proposed conductive mortar contributed to lower CP potential and higher current density and depolarization potential than the general mortar.

The Effects of Biofouling and Corrosion Products on Impressed Current Cathodic Protection System Design for Offshore Monopile Foundations

The robustness of the cathodic protection systems utilized for offshore wind monopile foundations depends on the surface condition of the steel as well as the environmental conditions. This study investigated how preexisting biofouling and corrosion products on vertical uncoated steel surfaces extending from the intertidal zone to the buried zone affected the cathodic protection requirements when impressed current cathodic protection (ICCP) was applied under tidal conditions. The comparative results between initially clean and previously fouled and corroded panel sets showed that the fouling and corrosion products increased both the initial and mean current densities. They also altered the composition, slowed the formation, and reduced the protective properties of cathodic chalks during nine weeks of deployment in seawater at Port Canaveral, Florida.