Journal of Chemical Engineering and Energy Materials

Abstract Corrosion of steel reinforcement in concrete structures is one of the most critical durability challenges facing global infrastructure, with annual economic losses estimated at approximately US$2.5 trillion, accounting for 3.4% of global GDP . This comprehensive review systematically examines the causes, monitoring technologies, and durability enhancement strategies for reinforcement corrosion in concrete structures. The electrochemical mechanism of corrosion involves anodic dissolution of iron (Fe → Fe²⁺ + 2e⁻) coupled with cathodic oxygen reduction (O₂ + 2H₂O + 4e⁻ → 4OH⁻), with rust formation and its 2-6× volumetric expansion relative to steel inducing tensile stresses exceeding concrete's tensile strength . Two primary depassivation mechanisms govern corrosion initiation: chloride-induced pitting corrosion, where chloride ions disrupt the passive γ-Fe₂O₃ layer, and carbonation-driven pH reduction compromising protective film stability . Monitoring technologies have evolved from conventional half-cell potential and linear polarization resistance methods to advanced techniques including electrochemical impedance spectroscopy (EIS), distributed fiber optic sensing, and AI-driven predictive models achieving >98% detection accuracy . Mitigation strategies encompass electrochemical methods (cathodic protection, chloride extraction, realkalization), corrosion inhibitors with demonstrated ~45% weight loss reduction, and emerging polymer-modified concretes reducing chloride penetration by 30-50% while extending service life by 2-3 times . The review concludes that effective corrosion management requires integrated approaches combining mechanistic understanding, advanced monitoring, and sustainable material solutions.

Abstract Nanotechnology-based coatings have emerged as transformative solutions for corrosion protection, addressing the fundamental limitations of conventional barrier coatings through multifunctional design and active protection mechanisms. This comprehensive review systematically examines the synthesis, performance, and long-term stability of advanced nanocomposite coatings for corrosion protection. Key material systems include intrinsically conductive polymers, 2D nanomaterials (graphene, graphene oxide), inorganic nanoparticles (CeO₂, SiO₂, TiO₂, ZnO), and stimuli-responsive nanocontainers. Electrochemical impedance spectroscopy (EIS) results demonstrate that H-CeO₂@GO/epoxy composite coatings maintain high impedance values of 10^9.45 Ω·cm² after 60 days of immersion in 3.5 wt% NaCl solution, while HQZn-PA nanocomposite coatings achieve an impedance modulus of 1.03 × 10^10 Ω·cm² after 40 days with a self-healing efficiency of 99.28% . Self-healing coatings incorporating corrosion inhibitor-loaded nanocontainers enable autonomous repair of coating damage through coordination-controlled release mechanisms triggered by pH, ions, or redox potential changes . Graphene-based coatings provide exceptional barrier properties through their 2D lamellar structure, with incorporation of 5 wt% graphene reducing corrosion rates from 3.4 × 10⁻² to 5.0 × 10⁻⁵ mmpy . Challenges persist in long-term stability under harsh service conditions, dispersion uniformity, scalability, and environmental sustainability.

Abstract Solid oxide fuel cells (SOFCs) represent a transformative energy conversion technology, yet their commercial viability is critically constrained by the high-temperature degradation of metallic interconnects. This comprehensive review systematically examines ceramic protective coatings for ferritic stainless steel interconnects operating at 650–850 °C, focusing on oxidation kinetics, scale adhesion mechanisms, and failure pathways. Manganese-cobalt oxide (MCO) spinel coatings have emerged as the leading candidate, effectively suppressing chromium oxide scale formation and mitigating cathode poisoning through volatile Cr species retention . Recent advances demonstrate that lanthanum-doped MCO coatings inhibit pore formation and maintain Mn/Co stoichiometry during long-term operation, extending protective service life . The oxidation mechanism follows parabolic kinetics, with coated Crofer 22 APU steel achieving an area-specific resistance (ASR) of 13.11 mΩ·cm² compared to 41.45 mΩ·cm² for uncoated steel after 500 hours at 800 °C . Reactive element additions—Ce, La, Y, Tb—modify scale growth and improve adhesion through reactive element effect mechanisms . Tb-doped CuFe₂O₄ coatings demonstrate reduced oxidation rates and ASR through maintaining a continuous chromia layer that inhibits outward Fe and Cr diffusion . Perovskite-spinel composites incorporating LaNi₀.₆Fe₀.₄O₃-δ exhibit enhanced oxidation resistance compared to pure spinel coatings after 3000-hour exposure . Interfacial shear strength evaluation through four-point bend testing reveals distinct differences between coatings formed with different process parameters . This review concludes that effective SOFC interconnect protection requires integrated coating design combining spinel-perovskite architectures with reactive element doping.

Abstract Corrosion in Vacuum Distillation Units (VDUs) represents a significant challenge for refinery operations due to the complex nature of the feedstocks and extreme operating conditions. The VDU is responsible for processing heavy atmospheric residue under vacuum conditions to recover valuable products such as light and heavy vacuum gas oils. However, the presence of sulfur compounds, naphthenic acids, chlorides, and high temperatures promotes multiple corrosion mechanisms that can severely impact the reliability and lifespan of the unit. This paper provides a comprehensive review of the most common corrosion types in VDUs, including high-temperature sulfidation, naphthenic acid corrosion, chloride-induced corrosion, and erosion-corrosion. It identifies critical areas prone to degradation such as the furnace tubes, flash zone, vacuum tower internals, and overhead lines. Monitoring techniques such as corrosion probes, ultrasonic thickness measurements, and infrared thermography are discussed for early detection and control. Furthermore, the paper outlines key mitigation strategies including material upgrades, chemical injection programs, enhanced crude desalting, and operational improvements. A case study from a Middle Eastern refinery is presented to demonstrate the practical application of these strategies and the measurable reduction in corrosion rates. The findings emphasize the importance of integrating proactive corrosion management into the overall maintenance and reliability programs of refineries to enhance safety, reduce downtime, and improve economic performance.

Abstract Corrosion in refinery units, particularly in Naphtha Hydrotreating (NHT) and Continuous Catalytic Reforming (CCR) units, represents a significant threat to operational reliability, safety, and economic efficiency. This study presents a comprehensive data-driven analysis of corrosion behavior in NHT and CCR units based on real-time plant data, historical maintenance logs, and process parameters. Using statistical and machine learning methods, we identify key operational factors contributing to corrosion rates, including temperature, pressure, hydrogen partial pressure, and contaminants such as chlorides and sulfur compounds. Furthermore, the study evaluates the effectiveness of different mitigation strategies such as corrosion inhibitors, metallurgy upgrades, process optimization, and vapor phase conditioning in various sections of the units, including reactors, heat exchangers, furnaces, and piping systems. It investigates how operating envelopes and process excursions influence the onset and progression of localized corrosion phenomena such as pitting, erosion-corrosion, and stress corrosion cracking. The findings aim to provide actionable insights for refining operators, integrity managers, and process engineers involved in asset management and corrosion control. The study further evaluates the effectiveness of various corrosion mitigation strategies including material upgrades, corrosion inhibitors, process control optimization, and predictive maintenance protocols. The findings aim to support refinery operators in making informed decisions to extend equipment life, reduce downtime, and enhance safety in high-temperature, hydrogen-rich environments.

Abstract In the present study, while identifying potential risks and classifying them according to the Risk Breakdown Structure (RBS), we determine the criteria for identifying and assessing risks qualitatively, and then by converting qualitative criteria into quantitative ones and using the FMEA technique and calculating the Risk Priority Number (RPN) and responding to high-priority risks, we control the obstacles to achieving the project goals. By carrying out this process in the oil processing unit construction project, which was carried out using the EPC method, important and risky risks were identified and controlled based on the project phases, and precise control was exercised to prevent imposing additional and possible costs on the project and creating defects in its other objectives, so that important and influential risks on key project activities were organized in the form of a risk management plan, and their future and possible consequences, which could be one of the most important factors in the failure to comply with the project implementation plan, were minimized. The results of the present study showed that approximately 43% of the losses were due to mechanical integrity failure, and this percentage was higher for losses caused by oil refinery. Of these mechanical failures, 70% were identified as a result of corrosion of process pipes, mainly due to internal corrosion. In cases where external corrosion was the cause, the cause was insulation corrosion.

Abstract Corrosion in Liquefied Petroleum Gas (LPG) units poses significant challenges to the safety, reliability, and efficiency of refining and petrochemical operations. These units operate under high pressure and varying temperature conditions, exposing metallic equipment to aggressive environments containing corrosive agents such as hydrogen sulfide (H₂S), carbon dioxide (CO₂), moisture, and trace acidic compounds. The interaction of these substances with carbon steel and other commonly used materials leads to various corrosion phenomena, including uniform corrosion, localized pitting, and stress corrosion cracking. Sweet corrosion, primarily driven by CO₂, results in the formation of iron carbonate protective scales under certain conditions, while sour corrosion induced by H₂S forms brittle iron sulfide layers that exacerbate metal degradation. Additionally, microbiologically influenced corrosion (MIC) caused by sulfate-reducing bacteria further complicates corrosion management in LPG storage facilities. Effective corrosion control requires a multifaceted approach involving material selection, chemical inhibitors, protective coatings, and rigorous operational monitoring. Electrochemical techniques such as Electrochemical Impedance Spectroscopy (EIS) and Linear Polarization Resistance (LPR) are widely employed for real-time corrosion rate assessment. Despite advancements in mitigation strategies, corrosion remains a critical concern due to its impact on operational costs, safety hazards, and equipment lifespan. Continued research and development are essential to optimize corrosion prevention methods and enhance the durability of LPG processing and storage infrastructure.

Abstract The production of polymers, particularly PVC and its related copolymers, requires stringent control of operating conditions to minimize occupational exposure to VCM. In industrial practice, VCM synthesis is typically conducted in fully closed systems, which effectively reduce atmospheric emissions and worker exposure. Nevertheless, due to its high flammability, VCM vapor poses a significant fire and explosion hazard. Accidental releases under pressure can also result in frostbite because of rapid depressurization. Furthermore, the potential for long–range vapor dispersion necessitates rigorous control of potential ignition sources and strict adherence to process safety protocols.
In this study, a comprehensive and rigorously validated process model for VCM production was developed using Aspen Plus. The balanced process, which integrates both direct chlorination and oxychlorination routes, was simulated to determine an optimized, energy–efficient, and industrially feasible configuration. Detailed molecular kinetic models were incorporated for all major reactor units, accounting for both primary and secondary reaction pathways. The thermodynamic framework was based on the modified SRK equation of state, ensuring accurate vapor–liquid equilibrium representation for multi-component systems. Model validation against published plant-scale data showed excellent agreement in conversion, selectivity, and yield predictions. The developed simulation framework provides a robust foundation for future work on process optimization, heat integration, and safety analysis in large-scale VCM production plants.

Abstract The relationship between industrialization and rural development in the texts of developing countries has different views, so that Rajesh Chandar has emphasized the role of industrialization in the development process by expressing these views and believes that the following views have made the role of industry in development more sensitive. Industrialization in developing countries is known as a historical necessity. In this regard, due to the lack of another provable model for development, historically this claim that development requires industrialization has been accepted. Due to the minimization of the competitiveness of the agricultural sector compared to the industrial sector and the significant reduction in the price of agricultural products compared to industrial products, the trade conditions in the agricultural sector are significantly limited and the tendency towards industrialization as it is an economic fact. Even if the manufacturing and production of goods in the process of industrialization is not considered as a desirable option for the development of the agricultural sector, the trend towards industrial activities can be a source of encouragement for the economic development process as a complement to the agricultural sector.

Abstract Corrosion in Naphtha Hydro treating (NHT) units poses a significant challenge to the long-term reliability and economic performance of petroleum refineries. These units operate under severe conditions—high temperatures, elevated hydrogen pressures, and the presence of corrosive species such as hydrogen sulfide (H₂S), organic acids, and chlorides—which create an aggressive environment for materials of construction. This study investigates the key operational factors that influence corrosion rates in an NHT unit using a six-month dataset from a hypothetical refinery scenario. Data collected includes reactor temperature and pressure, feed sulfur content, amine inhibitor dosage, and field-measured corrosion rates from corrosion coupons installed in critical locations. Statistical analysis revealed strong positive correlations between corrosion rate and both feed sulfur content (r = 0.81) and reactor temperature (r = 0.74), while amine inhibitor dosage showed a moderate inverse relationship (r = -0.66). A multiple linear regression model was developed to predict corrosion rate as a function of these parameters, with an R² value of 0.83, indicating high predictive accuracy. Corrosion hotspots were identified at the reactor inlet and in the cold zones of heat exchangers, suggesting the need for targeted monitoring and material upgrades in those areas. The study concludes that optimizing feed quality, maintaining appropriate inhibitor dosing, and deploying real-time corrosion monitoring can significantly mitigate corrosion risk. The findings provide a quantitative foundation for corrosion risk assessment in NHT units and offer actionable insights for improving operational safety and asset longevity in hydro processing environments.