Sacrificial Anode Cathodic Protection System Research Articles

Corrosion Mitigation and Cathodic Protection Design for Wet Oil Processing at Qubbat Baba: A Modeling and Simulation Approach using MATLAB Simulink

Oil produced from Qubbat Baba in the Kirkuk oil field -North Oil Company (NOC) requires pre-treatment at the refinery due to water, mineral salts, and sediments. The water contains soluble mineral salts like sodium, calcium, and magnesium chlorides. Failure to treat the crude oil can result in operational problems, such as equipment scaling, corrosion, fouling, and catalyst poisoning in the hydrotreating unit. The study focuses on corrosion in wet oil treatment equipment especially crude oil horizontal separators (process vessels). Corrosion in the internal chamber resulted from two factors: firstly, scale deposition occurred on the surface of Galvalume (GAIII) anodes (passivation phenomenon) during oil-water separation at elevated temperatures (60°C). Secondly, the existing cathodic protection system was inadequate for the crude oil's specifications and the current field's operating conditions for separators. The XRD and XRF chemical analysis revealed that a significant portion of these deposits consisted of Al2O3 and ZnO. Based on the provided reasons, the researchers suggested a new design for the Sacrificial Anode Cathodic Protection system (SACP) using MATLAB Simulink software.

Fundamental study on cotton-like fiber acting as electrolyte carriers in the sacrificial anode cathodic protection system for closed-section steel structures under atmospheric environments

In the pursuit of sacrificial anode cathodic protection (SACP) for closed-section steel structures exposed to atmospheric conditions, a cotton-like fiber serves as the electrolyte carrier. The efficacy of this approach was validated through assessments of water absorption, retention, electrochemical properties, and SACP trials. The cotton-like fiber exhibited notable hydrophilic characteristics, absorbing nearly seven times its weight of the electrolyte and retaining over 50% of its maximum water absorption capacity after 15 days. Furthermore, the ionic conductivity of the fiber, when fully saturated with 0.1 wt% NaCl aq, was nearly twice that of the same concentration solution without fibers, diminishing as the electrolyte content decreased. Additionally, the open-circuit potential (OCP) of the Al-3Zn sacrificial anode was approximately −0.2 V relative to steel. Moreover, Nyquist plots revealed that electrodes in fibers were more resistant to dissolution compared to those in 0.1 wt% NaCl aq. In the SACP tests, the combination of cotton-like fibers with the Al-3Zn anode exhibited a protective performance for steel members, as assessed by the current density, instant-off potential, and steel surface conditions.

Examination of the Potential Effect of Corrosion Current Density of Ship Hulls on the Sacrificial Anode Cathodic Protection

In this study, the sacrificial anode cathodic protection system, which is one of the electrical protection methods in the prevention of corrosion in ships, was examined. Within the scope of the study, the potential effects of corrosion current density, which is an important parameter for cathodic protection design, were studied. The study includes cathodic protection calculations for a bulker with a protected hull area of 9406 m2 and a general cargo ship with a protected hull area of 1770 m2. As a result, it was estimated that each 1 mA/m2 change in the electric current density parameter changes the anode usage amount by 64 kg in bulker and 12 kg in general cargo, depending on the reference parameters such as protected hull area, anode type, and design life. It can be stated that the evaluation of the corrosion current density parameter, taking into account the operating conditions of each ship, will be beneficial in terms of optimizing the sacrificial anode consumption.

Modelling of 3D periodic cathodic protection problems in reinforced concrete structures with accelerated boundary element method

The steel used for concrete reinforcement exhibits either active or passive electrochemical behavior. As long as the concrete environment remains highly alkaline, the steel remains passive. However, carbonation and/or chloride contamination of concrete will cause steel to become active and corrode. In the latter case, a common strategy is the use of cathodic protection (CP) systems to lower the potential of the steel at a protective level. The numerical modelling of cathodically protected concrete buildings and infrastructures usually requires large-scale models due to their size and complex geometry. An efficient modelling approach is to consider any possible periodicity in these problems by applying periodic boundary conditions to a representative volume element of the structure. The boundary element method (BEM) is extensively used for solving CP problems. A BEM formulation is proposed for solving 3D periodic CP problems in this work. The computation cost is reduced by applying acceleration techniques based on adaptive cross approximation (ACA). As an engineering application, a sacrificial anode CP system of a reinforced concrete column is designed, illustrating the importance of detailed modelling in the design of such systems. To this end, the macrocell corrosion problem is initially solved, and a parametric study with respect to concrete conductivity is carried out.

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.

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 Effectiveness Evaluation of Sacrificial Anode in Reinforced Concrete that has been Installed for One Year

Generally, reinforcing steel in concrete is protected from corrosion. This happens because the cement content in the concrete has an alkaline effect. It can reduce the risk of corrosion, but the reinforcing steel may still corrode if exposed to a corrosive environment. One method of providing a high protection value against corrosion is the sacrificial anode cathodic protection system. This study aims to evaluate the effectiveness of the sacrificial anode cathodic protection on reinforced concrete. Three types of specimens were used in the study. The specimens were (a) unconnected anode-cathode specimen, (b) connected anode-cathode (design 1), and (c) connected anode-cathode (design 2). The dimensions of the concrete specimen are 1000 mm in length, 100 mm in width, and 100 mm in height. Profometer 5+ was used to locate the reinforcing steel in the concrete. In this study, the condition of the protected criteria of reinforced concrete was achieved within 30 weeks in 2019 after wet-dry cycle treatment in 3.5% NaCl media, and thus, the specimen was exposed in an open air for one year. In 2020, all of the specimens were treated again with a wet-dry cycle for 3 weeks to measure the potential value of the reinforcing steel after a year. The measurement result of the corrosion potential value after one year showed that the specimen (c) had a potential value of -884.67 mV. While the specimen (b) had a potential value of -689 mV. These results show that the specimen (c) still within the protected criteria based on the NACE standard after one year of exposure, whereas the specimen (b) is no longer protected after one year of exposure.

Optimisation of sacrificial anode cathodic protection system in chloride-contaminated reinforced concrete structure

For chloride-contaminated reinforced concrete (RC) structures, sacrificial anode cathodic protection (SACP) is an effective method to control steel corrosion. However, some adverse phenomenon, such as insufficient protection current or excessive anode consumption, might affect system operation. The motivation of this work is to optimize SACP systems by generating optimal tradeoff between its efficacy and efficiency: 1) maximizing the steel corrosion current reduction; and 2) minimizing the anode mass consumption. In this study, five SACP systems in chloride-contaminated beam were simulated to investigate the influence of anode arrangement on the steel corrosion current reduction and anode consumption. The result reveals that halving the anode spacing has better improvement on corrosion current inhibition compared to doubling anode size. Simultaneously, it was found that corrosion current reduction was accompanied by significant increase in the cathodic current, and this increment of cathodic current leads to more than 50% additional anode consumption. Based on a comprehensive evaluation, in an SACP system, when the current supplied by anode corrosion is 5.0–7.5 times steel corrosion current, the SACP system efficacy and efficiency can be balanced.

Conceptual Sacrificial Anode Cathodic Protection Design for offshore wind monopiles

The design and implementation of a cathodic protection system for offshore steel monopiles used to support wind turbines are required to protect them from corrosion. This paper uses the recommended practice DNVGL-RP-B401-Cathodic Protection Design to demonstrate the step-by-step sacrificial anode cathodic protection system design of an offshore monopile located off the coast of Massachusetts. It compares the requirements for coated and uncoated structures and discusses the other factors that need to be taken into consideration.

Corrosion control of reinforced concrete structures in construction industry: A review

Corrosion of steel reinforcement is one of the main deterioration phenomena which affect the durability of reinforced concrete structures. Together with the structural damages, corrosion will also increase the cost associated with it. Therefore, protection of reinforcing steel in concrete structures from corrosion is an inevitable need. Various protection techniques are in practice to mitigate corrosion of reinforcing steel in the concrete structure such as use of patch repairing, protective coating, impressed current method, and sacrificial anodes. Among these, electrochemical protection technique using sacrificial anodes can be suggested as a very effective tool for corrosion mitigation. Sacrificial anode cathodic protection system is a less popular corrosion control technique because of lack of awareness about the benefits of this method and the wide usage of other corrosion control practices. This paper provides a critical review on the common techniques in construction sites used for corrosion control of reinforced concrete structures. An overview of the benefits of sacrificial anode cathodic protection system, its working and installation is also provided in this paper.

The Effect of Stray Current from Sacrificial Anode Cathodic Protection (SACP) System on the Adjacent Unprotected Reinforcing Steel

Concrete protects reinforcing steel from corrosion, but the steel may be corroded if exposed to coastal environment. Cathodic protection is a popular method to protect steel structures from corrosion. Previous researchers have conducted studies on sacrificial anode cathodic protection (SACP). However, the effect of stray current on the unprotected reinforcing steel in concrete was not reported. This study aims to analyze the effect of the stray current phenomenon on reinforcing steel which are not protected by SACP. Three types of specimens were used in the study: (1) unconnected anode-cathode, (2) connected anode-cathode, and (3) partially connected anode-cathode. The specimens were treated with 30 weeks of wet-dry cycle. Half-cell potential technique was used to measure corrosion potential. The results show that the first specimen had an average potential value of -505.44 mV, meanwhile the second specimen had average potential value -883.66 mV. According to ASTM C876 criteria, the first specimen is categorized into high corrosion risk. While, the second specimen was protected from corrosion based on NACE standard. However, the result on the third specimen shows that only the first reinforcing steel was protected from corrosion, while the other steels were categorized as severe corrosion risk level. The result on third specimen indicates that the stray current produced by SACP system could cause negative effect on the reinforcing steel by increasing susceptibility to corrosion, instead of protecting them.

DESIGN ANALYSIS OF IMPRESSED CURRENT CATHODIC PROTECTION (ICCP) SYSTEM FOR UNDERWATER STRUCTURE OF INDONESIAN WARSHIP (KRI)

In carrying out these basic tasks the Navy relies heavily on the readiness of the Indonesian Warship (KRI),including the readiness of underwater construction in KRI from corrosion attack on sea water. Nowadays, KRIuses Sacrificial Anode Cathodic Protection (SACP) from corrosion attack. Whereas, SACP system has someweakness, such as the lifetime protection is short. The aim of this paper is to the analysis of Impressed CurrentCathodic Protection (ICCP) design of the underwater structure of KRI using computative theory calculation andspecimen test. The results of ICCP design showed that the specimens I required 0.081 Ampere (A) forprotection current, specimen 2 required 0.010 A for protection current, specimens 3 required 0.00251 A. Withpotential protection between -800 mV up to -1100 mV, it described that the ICCP system is reasonable. Theresult of cathodic protection design towards an underwater structure of KRI (TR-40 Type) showed that 1.75 forAmpere (A) and 3.35 volt DC for voltage. The benefit of this paper is a reference standard in the planning of theICCP design at KRI.Keywords: Corrosion, Underwater Structure of Warship, Impressed Current Cathodic Protection (ICCP).

The Experimental Measurement on the Throwing Power of Sacrificial Anode Cathodic Protection for Concrete Piles in Natural Sea Water

This paper represents the experimental studies on the throwing power of sacrificial anode cathodic protection system applied to reinforced concrete piles in salt water condition by means of zinc anodes. Many previous studies show the effectiveness of sacrificial anode cathodic protection system, however, the major problem of sacrificial anode cathodic protection system is limited a distance to the point reaching protection current from the anode in high resistivity environments such as concrete, etc. In case of concrete pile in sea water condition, it should be combined submerged zone, tidal zone, splash zone, and atmospheric zone. In this study, the cathodic protection current by zinc sacrificial anodes was limited to scores of centimeters above the water line with tidal, depending on the concrete resistivity. Experimental tests were carried out on pile type reinforced concrete specimens with the change of water level. The test factors were corrosion and protection potential, current, and 4 hour depolarization potential. As a result of tests, cathodic protection current by zinc sacrificial anode was influenced up to about 10cm above the water line, and high resistivity areas such as atmospheric zone could not be protected with this system.

Cathodic Protection Effect of Reinforced Concrete Beam Specimens with Zinc Sacrificial Anode in Marine Environment

This study is to acquire the confirmation data regarding the cathodic protection characteristics for reinforced concrete beam specimens with zinc sacrificial anode in 15% salt water. It was possible to confirm the performance of sacrificial anode cathodic protection system by the measurement of potentials and concrete resistivity for the reinforced concrete beam specimens applied with zinc sacrificial anode in mortar topside of the concrete specimens. The corrosion potential and cathodic protection potential were measured by potentiostat, and 4 hour depolarization potentials were measured after disconnecting with anode for 4 hours. It was confirmed that the cathodic protection for reinforced concrete structures by means of zinc sacrificial anode were very effective corrosion protection technology in marine environments.

The effect of cathodic protection system by means of zinc sacrificial anode on pier in Korea

This study has been conducted to confirm the effect of sacrificial anode cathodic protection system for 90 days to protect corrosion on pier that is located in Korea. The cathodically protected structure was a slab and a pile cap. Before the construction of cathodic protection system, the macrography was carried out. As a result of the macrography, many corrosion traces were confirmed in this structure. The trace was mainly focused on joint and zones that concrete cover was eliminated. To apply the cathodic protection system, many onsite techniques have been adopted. In addition, to confirm the inner state of steel in concrete properly, a corrosion monitoring sensor (DMS-100, Conclinic Co. Ltd) has been applied. Test factors were corrosion & cathodic protection potential, 4 hour depolarization potential, resistivity and current density. After 90 days from the installation of cathodic protection system, it could confirm that proper corrosion protection effect was obtained by considering the result of tests.

Cathodic Prevention and Cathodic Protection of Zinc Mesh Sacrificial Anode for Reinforced Concrete in 15% Salt Water

This study is to acquire the confirmation data regarding the cathodic protection and cathodic prevention characteristics for concrete piles in marine bridges and piers exposed to harsh marine environments. It was possible to confirm the performance of cathodic protection by the measurement of potentials and current density the concrete pile specimens applied with zinc mesh sacrificial anode cathodic protection system. The current density for the cathodic protection (CProt) that CP started after a repair of corrosion was higher than that for the cathodic prevention (CPrev) that CP commenced from the beginning of experiment, and 4 hour depolarization potentials were higher in the CPrev system than in the CProt one, and it was confirmed that the CPrev has more protection effect with less protection current, comparing to the CProt.

Effect of soil resistivity on the design of sacrificial anode cathodic protection system

In this research, the effect of soil resistivity on the sacrificial cathodicprotection of a pipeline steel of oil was studied. Sufficient sacrificial cathodicprotection could be obtained at various soil resistivty for different types ofanodes. High current output (2.98, 2.38 and 8.33 Amps) of Zn, Al and Mganodes respectively, are obtained at 25 ohms.cm soil resistivity. Simultaneous,for the same conditions, low numbers and large weights of anodes are requiredto satisfy protection

Numerical Simulation of Cathodic Protection for Jack-Up Platform

For the jack-up platforms' huge size and complex structure, as well as the variation and complexity of their ambient corrosion environment, problems often arise in cathodic protection (CP) systems. The rise of the computer and the numerical simulation technology provide a new technical method to the prediction, evaluation and optimization of CP system for jack-up platform. Numerical simulation method has the advantage of examining potential maps of the entire structure easily and then the designer can determine the number and placement of anodes required to provide protection from the under and over protection regions based on a generic polarization response. In this paper the 3-D boundary element method was used to calculate the mathematical model of sacrificial anode CP system for a jack-up platform. Introduced piecewise quasi linearized method to deal with nonlinear problem of boundary conditions. Adopt block boundary element method to solve electrolyte inconsistency problem and points regional modeling to solve electrolyte discontinuous. From the results we can conclude that the jack-up platform sacrificial anode CP system meets the protection targets.

Experimental Study on the Effect of Cathodic Protection System for Concrete Slab Specimens with Zn-Mesh Sacrificial Anode in Marine Environment

This study is to acquire the confirmation data regarding the cathodic protection (CP) characteristics for slabs in marine bridges and piers exposed to hash seawater environments. It was possible to confirm the performance of CP only by the measurement of CP potentials for the slab specimens applied with zinc mesh sacrificial anode CP system. The CP current density for the cathodic protection (CProt) that CP started after a repair of corrosion was 2 times higher than that for the cathodic prevention (CPrev) that CP commenced from the beginning of experiment, and the most of protection current density (87.0-91.5%) flew to the closer top rebar in slab specimens. 4 hour depolarization potentials were higher in the CPrev system than in the CProt one, and it was confirmed that the CPrev has more protection effect with less protection current, comparing to the CProt. It was also confirmed that the CP of both CPrev and CProt by means of zinc mesh sacrificial anode for reinforced concrete structures were very effective corrosion protection technology in marine environment.

Three Year Performance of Sacrificial Anode Cathodic Protection System in the Reinforced Concrete Bridge Structures

The aim of this study was to obtain special cathodic protection (CP) behavior in coastal bridge structures. This bridge structure was located to the area where repetition between fresh water and sea water taken place due to ebb and flood tide. In this study, zinc-mesh anode was used as a sacrificial anode. Thus, it was a good opportunity to verify the effectiveness of sacrificial anode CP (SACP) in this special location. Measurement was conducted for three years. Test Factors were corrosion potential, CP potential, 4 hour depolarization potential, and CP current. Moreover, resistivity and corrosion rate were measured by the multi-functional corrosion monitoring sensor (DMS-100, Conclinic Co. Ltd) that could measure potential, galvanic current, corrosion rate, concrete resistivity, and temperature. After three years from installation of CP, it could confirm that although some pier showed low depolarization potential less than 100mV, most piers showed good protection both electrochemical and physical aspects.