Journal of Chemical Engineering and Energy Materials

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 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 During six decades of development planning at the level of developing countries, which has been done with different forms and patterns. Development planning has not had a proper place and rural development is mainly based on tourism perspectives or physical functions and has never led to introspection and self-criticism, so that in our country in the last few decades by providing amenities and services to the villages, the process of migration has not decreased, and the provision of facilities without planning for employment and income has increased the expenses of the residents of the rural areas of the country, while the income has remained constant. In this way, rural areas have always played a role related to urban areas as a margin and far from the comprehensive thinking of development. Creating industries is one of the strategies that help the development of villages, the industrialization of rural areas as an accelerator for creating sustainable employment and the most effective solution to solve the problem of rural unemployment. The theory of industrialization and the optimal planning of industries in rural areas are considered as a catalyst for creating sustainable employment and as a last resort to solve the problem of poverty in the potential areas of the same region to solve the problem of unemployment and a soothing factor for disadvantaged rural areas. Come the consequences of the appropriate establishment of rural industries in temperate and humid rural areas, where the amount of agricultural land is decreasing every day, is considered a suitable solution.

Abstract Graphene is a two-dimensional (2D) planar sheet of carbon atoms in a hexagonal configuration where the atoms are sp2-bonded [33]. Graphene sheets are formed by placing carbon atoms together. In a graphene sheet, each tetravalent carbon atom is connected to three other carbon atoms with three covalent bonds. These three links are on the same plane and the angles between them are equal to 120 degrees. In 2004, a group of physicists at the University of Manchester, led by Andre Geim and Kostya Novoselev, used a simple and very different method to produce graphene, leading to a revolution in the field. Using 3D graphite, they produced a single sheet (a monolayer of atoms) of it through a micromechanical layer-by-layer method. This method led to the easy production of high-quality graphene crystals with dimensions of more than one hundred micrometers. Graphene, this two-dimensional nanomaterial (2D) is the newest member of the family of multidimensional carbon materials, which includes fullerenes as zero-dimensional nanomaterials (0D), single-walled carbon nanotubes (SWNT) as one-dimensional nanomaterials (1D), and graphite as a three-dimensional material (3D). Graphene is a two-dimensional allotrope of carbon (one atom thick) with a honeycomb structure. In terms of strength, this material is one of the strongest materials known so far. This composition is the basic constituent of carbon nanotubes and large fullerenes.

Abstract Corrosion is a critical concern in refinery operations, particularly within the Crude Vacuum Unit (CVU), where high temperatures, acidic compounds, and variable feedstock compositions create a highly aggressive environment. This study investigates the extent and nature of corrosion affecting major components of the CVU, including furnace tubes, transfer lines, flash zones, and overhead condensers. Using ultrasonic thickness gauging (UTG), process stream analysis, and historical inspection data, corrosion rates were calculated and correlated with metallurgical characteristics and process conditions. The findings reveal that the highest corrosion rates occurred in the transfer lines due to naphthenic acid corrosion (NAC), especially under conditions with Total Acid Number (TAN) exceeding 1.0 mg KOH/g and operating temperatures above 230°C. Sulfidation in furnace tubes and erosion-corrosion in overhead systems were also prominent. Material selection played a significant role in corrosion resistance, with carbon steel components showing higher degradation compared to low-alloy and stainless steel counterparts. The study emphasizes the importance of feed monitoring, material upgrading, and optimized wash water injection to mitigate damage. Recommendations include the use of corrosion-resistant alloys, installation of online monitoring systems, and improved process control strategies. This research provides valuable insights for maintenance planning and risk reduction in vacuum distillation operations, contributing to improved asset integrity and operational efficiency in refineries.

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.