Petrochemical Industry Research Articles

High throughput MN4-G screening electrocatalyst for highly selective acetylene semi-hydrogenation

The large-scale production of polyethylene in the petrochemical industry requires the effective removal of trace amounts of acetylene impurities. Currently, acetylene is selectively reduced to ethylene via catalytic hydrogenation under high-temperature and high-pressure conditions. However, owing to the harsh reaction conditions of this thermocatalytic method, it requires significant energy and lacks selectivity. Electrocatalytic acetylene semi-hydrogenation (EASH) has emerged as a promising alternative to traditional thermal catalytic hydrogenation. In this study, the density functional theory (DFT) calculations were used to systematically investigate the electrocatalytic activity and selectivity of 25 nitrogen-doped graphene composites containing 3d, 4d, and 5d transition metals (MN4-G) toward EASH, aiming to identify efficient single-atom catalysts (SACs) for EASH reactions. Firstly, the binding, cohesive, and formation energy calculations reveal that all single metal atoms except Mo, Ru, Ag, W Re and Os can be stably immobilized on nitrogen-doped graphene. Secondly, the Gibbs free energy diagram exhibits that Cu and Ni SACs promote EASH and inhibit the hydrogen evolution side reaction. Moreover, the d-band center of the metal site and the acetylene adsorption energy can be used as characteristic descriptors to predict the EASH selectivity of the catalyst. Finally, the mechanism of catalytic activity is described from the perspective of electrons and orbitals, revealing the coupling between dz2 and C2H4-πz∗ orbitals plays a vital role in ethylene desorption. This study provides an in-depth understanding of the mechanism of high-efficiency EASH catalysts at the electronic orbital level.

Effect of cobalt on Microstructure and toughness properties of 9Cr-1.8W-0.4Ni-xCo weld metal

In this research, microstructural characterization and mechanical properties of 9%Cr, 0.4%Ni (including W and Mo) steel weld metal with alloyed cobalt were investigated. Due to their strong creep resistance, oxidation resistance, and low thermal expansion, 9%Cr steels are used in nuclear power plants, petrochemical industries, and fossil fuel-powered power plants that operate in high temperature conditions. In this context, weld metals comprising 0.5 %, 1 % and 1.5 % cobalt and cobalt-free weld metal were produced by SMAW (shielded metal arc welding) technique. Microstructure of the weld metals were characterized with optical microscope (OM), scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). Also, XRD analysis was performed on the bulk samples and precipitated carbide/nitride phases extracted from the weld metals. In addition, differential scanning calorimetry (DSC) was used to determine the phase transformations. Thermo-Calc modeling study was also performed. Hardness, tensile and Charpy-V impact tests were carried out to determine the mechanical properties. The hardness did not change significantly when cobalt up to 1.5 % in the weld metal. However, with the increase of cobalt, the yield and tensile strength increased without affecting the elongation value too much. In the Charpy impact tests performed at different temperatures (−40 °C, −20 °C, +20 °C, +40 °C, +60 °C), the amount of cobalt increased toughness, especially at +40 and + 60oC temperatures. Ductile brittle transformation temperature (DBTT) of the weld metal with 1.5 % Co decreased from 29 °C to 15 °C compared to cobalt free weld metal. It is thought that this may be caused by the further separation of C, Cr and W from the matrix through forming precipitate by the cobalt effect. Besides the mechanical properties, microstructure was also affected by adding Co with inhibition of delta ferrite formation which decrease the toughness. Curie temperature increased with increasing cobalt content detected by DSC.

Velocimetry of coarse particles in pipeline flow based on GMM model and flow direction constraints

Coarse particle vertical pipeline hydraulic transport has been widely used in deep sea mining, petrochemical industry and shaft slag removal. The precise measurement of the velocity of coarse particles within a solid–liquid two-phase flow in a vertical pipe constitutes a pivotal and challenging aspect when investigating particle motion characteristics. We introduce a method for measuring coarse particle velocity that combines a GMM motion detection model with flow direction constraint matching. In this approach, a high-speed camera system captures the flow image of solid–liquid two-phase flow within a pipeline, and the GMM model analyzes the image to detect the motion particles. Subsequently, a rapid particle matching algorithm, incorporating flow direction constraints, is formulated to establish the particle matching relationships. Simulation and real experiments substantiate the efficacy of this method. Moreover, the method achieves high-precision matching with an accuracy of up to 99%. For videos captured at 30 frames per second (fps), the method enables real-time speed measurement, with an overall measurement error of less than 5%. In summary, this is an effective method for measuring coarse particle velocity field which is important to the study of the motion characteristics of solid–liquid two-phase flow.

Replacing Gray Hydrogen with Renewable Hydrogen at the Consumption Location Using the Example of the Existing Fertilizer Plant

The production and use of hydrogen are encouraged by the European Union through Delegated Acts, especially in sectors that are difficult to decarbonize, such as the industrial and transport sectors. This study analyzes the possibility of partial decarbonization of the existing plant in the petrochemical industry, with a partial transition from natural gas to renewable hydrogen, as a precursor to the adoption of the hydrogen economy by 2050. This study was based on the example of a plant from the petrochemical industry, namely an existing fertilizer plant. Namely, in the petrochemical industry, hydrogen is produced by steam-reforming natural gas, which is needed in the process of producing ammonia, one of the basic raw materials for mineral fertilizers. By building an electrolyzer at the location of the existing fertilizer plant, it is possible to obtain renewable hydrogen, which enters the ammonia production process as a raw material. The electricity from which hydrogen is produced in the electrolyzer is provided through Power Purchase Agreement contracts concluded with electricity producers from 12 wind power plants. The results of this study show that the production of renewable hydrogen at the location of the analyzed plant is not profitable, but due to the specificity of the process of such an industry, the high consumption of natural gas, and large savings in CO2 emissions which can be achieved by the production of renewable hydrogen, investment is needed. With a 370 MW electrolyzer, about 31,000 tons of renewable hydrogen is produced, which represents about 50% of the hydrogen needs of the analyzed plant. By producing renewable hydrogen for part of the needs of the analyzed plant, a saving of about 300,000 tons of CO2 emissions is achieved in relation to the production of gray hydrogen, which contributes to the partial decarbonization of the analyzed plant. The authors are aware that the current market opportunities do not allow the profitability of the investment without subsidies, but with the advancement of technology and a different price ratio of electricity, natural gas, and CO2 emissions, they believe that such investments will be profitable even without subsidies.

Olfactory-chemical establishment using odour wheels and fingerprints to manage odor pollution for the petrochemical industry

The odor nuisance may cause major environmental issues, so identifying the odor characteristics is important for odor management and traceability in the petrochemical industry. In this study, odour wheels and fingerprints were applied to manage odor pollution in the petrochemical industry. First, the odor profile method and portable electronic nose evaluation were applied to analyze the flavour sensory profiles of five upstream and downstream petrochemical plants, in order to grasp the odor natures of plants. Second, 375 organized and unorganized samples of 5 plants were analyzed by gas chromatography-mass spectrometry (GC–MS) technology, and a total of 583 odorants were obtained, including sulfur compounds, alcohols, esters, aldehydes, ketones, acids, alkanes, alkenes, halogenated hydrocarbons, aromatic hydrocarbons, nitrogen compounds, and other compounds. Third, the key odorants were identified by gas chromatography-olfactory (GC-O) and odor activity value (OAV) analysis. Fourth, the fingerprint spectras were developed by the identification of key odorants and process sources through principal component analysis. For plant A, 21 odorants were confirmed, including naphthalene, 1-methylnaphthalene, 2-methylnaphthalene, 1-methylindene, and 2-methylindene. Methyl methacrylate, acetophenone, isobutene, 4-vinyl-1-cyclohexene, acrylonitrile, and styrene were key element for plant B. The fingerprint factor of plant C had 20 odorants, including methanol, butanol, 2-ethylhexanol, acetic acid, and ammonia. And there were 21 odorants for plant D and 14 odorants for plant E, respectively, with similar substance types, including 2-ethyl-2-hexenal, 3-methyl-4-heptanone, isobutyl butyrate, and 1,2,3,5-tetraethylbenzene. Finally, the odor wheels were established by the correlation analysis between odorants and malodor, and compounds in fingerprint spectra weaker related to malodor of plants were removed. Hence, the characteristic odorants of each plant were further clarified, and the odors were associated with compounds, achieving rapid diagnosis and traceability of odor pollution in the petrochemical park. This provided new ideas and technical methods for odor pollution monitoring and identification.

Development of a wheeled wall‐climbing robot with an internal corner wall adaptive magnetic adhesion mechanism

AbstractThe wall‐climbing robot is a growing trend for robotized intelligent manufacturing of large and complex components in shipbuilding, petrochemical, and other industries, while several challenges remain to be solved, namely, low payload‐to‐weight ratio, poor surface adaptability, and ineffective traversal maneuverability, especially on noncontinuous surfaces with internal corners (non‐CSIC). This paper designs a high payload‐to‐weight ratio wheeled wall‐climbing robot which can travel non‐CSIC effectively with a payload capacity of up to 75 kg, and it can carry a maximum load of 141.5 kg on a vertical wall. By introducing a semi‐enclosed magnetic adhesion mechanism, the robot preserves a redundant magnetic adsorption ability despite the occurrence of significant gaps between localized body components and the wall surface. In addition, by ingeniously engineering a passive adaptive module into the robot, both the surface adaptability and crossability are enhanced without increasing the gap between the body and the wall, thereby ensuring the optimization of the adsorption force. Considering the payload capacity and diversity when climbing on vertical walls, inclined walls, ceilings, and internal corner transitions, control equations for internal corner transitions and comprehensive simulations of magnetic adsorption forces are performed using FEA tools. Finally, a functional prototype was developed for rigorous experimental testing, with the results confirming that the robot successfully meets the desired functionality and performance benchmarks.

Application and optimization of electro-Fenton technology in advanced treatment of petrochemical industry wastewater

Within this research endeavor, a refined electric-Fenton remediation protocol was put forth for the enhanced reconditioning of intensely polluted organic effluents originating from the petrochemical sector. Using DSA (Dimensionally Stable Anode) electrode material and ultraviolet (UV) catalysis, the wastewater treatment efficiency and the ability to degrade refractory organic compounds were significantly improved. By optimizing the reaction parameters, the mineralization speed and treatment efficiency of organic matter are significantly improved, the use of H2O2 is reduced, and the cost of chemicals and energy consumption are reduced. At the same time, the technology avoids the use of a large number of harmful chemicals and mitigates the peril of subsequent contamination, thus rendering it appropriate for a spectrum of petrochemical effluents. Moreover, it exhibits efficacious abatement on diverse categories of organic contaminants.

A large-scale synthesizable superhydrophobic C2H6- selective MOF for C2H6/C2H4 separation

Developing C2H6-selective adsorbents for efficient separation of C2H6/C2H4 is of great significance for the petrochemical industry. Numerous C2H6-selective adsorbents have been created, but their applicability in real-world industrial settings is severely constrained by their unscalable production and generally low stability (particularly water resistance). Herein, we proposed a series of C2H6-selective adsorbents CUPMOF-2-M (M = Zn, Mn, Cu, Mg), in which CUPMOF-2-Zn (also termed MET-6) not only possesses good C2H6-selective separation effect but super-hydrophobicity and low cost. At 298 K and 80 % relative humidity, CUPMOF-2-Zn only adsorbs 0.4 mmol·g−1 of water, outperforming all previously reported C2H6-selective materials in terms of hydrophobicity. Moreover, dynamic breakthrough experiments solidly demonstrated that CUPMOF-2-Zn can efficiently separate C2H6/C2H4 in high humidity conditions. More importantly, CUPMOF-2-Zn can be synthesized in a large-scale at room temperature (one batch 10 kg), which is essential to industrial implementation for separation of C2H6/C2H4.

Study on the lower limit of gas detection based on the snapshot infrared multispectral imaging system

Snapshot multispectral imaging system is extensively utilized in the petrochemical industry for gas monitoring due to its intuitive imaging, traceability, and ability to monitor a wide range of gases. Determining the detection capability of the different bands of the multispectral camera for the gases to be monitored is a crucial prerequisite for the operationalization of the camera. The current evaluation methods of detection capability are mainly for single-spectrum cameras, which require constructing complex experimental environments and have poor applicability to different gases. This paper proposes a radiation full-link simulation model, which can accurately calculate the degree of response and detection capability of each channel of the multispectral system for different types and concentrations of gases under various conditions. The gas detection capability of the self-developed uncooled multispectral gas cloud imaging camera was tested in the laboratory. Eleven industrial gases of different concentrations were detected, and the response error between the actual test results and the model simulation results was about 8.7%. This study is of great significance for the detection methods and applications of hazardous gases in chemical parks.

Ionic liquid mediated one-step perpendicular assembly in block copolymer thin films for ultrafiltration membrane applications

The rapid rise of oil and gas, petrochemical, food processing, and pharmaceutical industries has added a complex mixture of contaminants like oil, particulates, metals, and other organic compounds to wastewater. Multipurpose membranes with precise pore structure can offer a solution to this problem and block copolymers (BCP) can be used to achieve such structures. Achieving vertical assembly of BCP domains provides a perfect template for developing uniform through film channels for separation and transport of material, besides being useful for the rectification of defects in photolithography patterns. Producing such morphologies may require extensive film/substrate processing and is not always feasible for scale-up. With this article, we demonstrate a facile solution casting method to induce vertical domain assembly in as-cast diblock copolymer thin films in the presence of an ionic liquid (IL) additive that preferentially segregates to one block and neutralizes interfacial interactions. We also show the tunability of domain sizes by controlling the additive concentration. These vertically aligned morphologies are important for the development of next-generation lithographic techniques and form excellent templates for ultrafiltration membranes with uniform pore sizes. This article demonstrates how IL additives can be used to obtain stable non-equilibrium morphologies in as-cast BCP films and the effect of BCP molecular mass, block volume fractions, and IL content on self-assembly.

Hygienic assessment of the carcinogenic risk to the health of the population of the industrial district of Samara due to atmospheric air pollution

The article presents the results of a study assessing the possible risks of the population living in one of the districts of the city of Samara. The object of the study is the Kuibyshev district of Samara. The high anthropogenic load of the district is formed by enterprises of the oil refining and petrochemical industries, enterprises for the production of metal structures, sewage treatment plants, construction facilities, as well as intensive traffic flow. The initial information for assessing public health risks was the data obtained during the analysis of ambient air samples, as well as the results of calculations of the dispersion of pollutant emissions to nearby territories from the leading industrial enterprises of the district and mobile sources. The research was carried out in several stages. At the first stage, we identified the main sources of ambient air pollution, took into account the terrain, wind directions, and the nature of pulse operation of a number of leading sources. At the second stage, 6234 studies of ambient air samples taken in the Kuibyshev district of Samara, were conducted, priority substances were identified, and carcinogenic hazard indices (HRIc) were calculated. The data obtained indicate that the risks to public health are primarily formed as a result of atmospheric pollution with substances such as nitrogen dioxide, sulfuric acid, sulfur dioxide, a mixture of hydrocarbons, hydrogen sulfide, benzene. The main pollutants forming the level of the total carcinogenic risk to the health of the Samara population are hexavalent chromium and benzene. The total carcinogenic risk to the health of the population of the Samara region with a high degree of anthropotechnogenic load during the study period belongs to the 2nd range of reference boundaries and is characterized as acceptable, however, with the simultaneous presence of various pollutants in the air, an unfavorable background of combined effects on the body is created, which can lead to the formation of a certain pathology in the population.

Pricing and Inventory Decisions for the Apparel Industry Under a Carbon Neutrality Target with Green Investments and Recycling Efforts

The apparel industry is the second largest source of pollution globally, following only the petrochemical industry in terms of environmental pollution caused by production, sales, and consumption processes. Low-carbon, environmentally friendly, and energy-efficient production and consumption methods are crucial pathways for the apparel industry to achieve carbon neutrality targets. Therefore, considering green investments in apparel products and the recycling of discarded apparel, this paper investigated the inventory and pricing optimization decisions of apparel enterprises within the context of a carbon neutrality target. The results indicated that green investment or recycling can effectively increase the total profits of the apparel brand. Due to the cumulative effect of comprehensive environmental strategies, apparel brands achieve greater profits when simultaneously adopting both green investments and recycling efforts compared to implementing either one alone. Green investments focus on reducing the environmental impact during production by minimizing resource consumption and emissions from the source, while recycling emphasizes product reutilization, effectively extending the utilization cycle of resources. By implementing these two strategies, brands not only reduce the negative environmental impacts during production but also maximize resource reuse throughout the product lifecycle.

Pervaporation Dehydration Mechanism and Performance of High-Aluminum ZSM-5 Zeolite Membranes for Organic Solvents.

Membrane-based pervaporation (PV) for organic solvent dehydration is of great significance in the chemical and petrochemical industries. In this work, high-aluminum ZSM-5 zeolite membranes were synthesized by a fluoride-assisted secondary growth on α-alumina tubular supports using mordenite framework inverted (MFI) nanoseeds (~110 nm) and a template-free synthesis solution with a low Si/Al ratio of 10. Characterization by XRD, EDX, and SEM revealed that the prepared membrane was a pure-phase ZSM-5 zeolite membrane with a Si/Al ratio of 3.8 and a thickness of 2.8 µm. Subsequently, two categories of PV performance parameters (i.e., flux versus separation factor and permeance versus selectivity) were used to systematically examine the effects of operating conditions on the PV dehydration performance of different organic solvents (methanol, ethanol, n-propanol, and isopropanol), and their PV mechanisms were explored. Employing permeance and selectivity effectively disentangles the influence of operating conditions on PV performance, thereby elucidating the inherent contribution of membranes to separation performance. The results show that the mass transfer during PV dehydration of organic solvents was mainly dominated by the adsorption-diffusion mechanism. Furthermore, the diffusion of highly polar water and methanol molecules within membrane pores had a strong mutual slowing-down effect, resulting in significantly lower permeance than other binary systems. However, the mass transfer process for water/low-polar organic solvent (ethanol, n-propanol, and isopropanol) mixtures was mainly controlled by competitive adsorption caused by affinity differences. In addition, the high-aluminum ZSM-5 zeolite membrane exhibited superior PV dehydration performance for water/isopropanol mixtures.

Oxygen corrosion of reboiler tube served in production of dilution steam from heat exchanger of petrochemical refinery

This paper reports the oxygen corrosion of heat exchanger tubes serviced in dilute steam generation system. The floating head heat exchanger employed in a petrochemical industry underwent remnant corrosion failures particularly at lower passes of tube bundle. Initially remote field eddy current inspection technique was employed for tube bundle conditional assessment and further, root cause of degradation of tube had been analyzed. Comprehensive experimental techniques including visual examination, tube chemistry analysis, external tube surface morphological analysis, elemental mapping, scanning electron microscopy, light microscopy and x-ray diffraction studies were employed. The tube surface at the degraded position with its cross sectional examination was rigorously evaluated as well. Moreover, actual steam parameters such as pH, conductivity and iron & chloride concentration have been monitored in the petrochemical facility. The detailed analysis concluded that dissolved oxygen in boiler feed water (BFW) was the root cause for corrosion failure. Several other foreign elements were detected and source of each element was discussed in the context of actual heat exchanger operating conditions. Simulated conditions of BFW service have electrochemically been evaluated in two different dissolved oxygen concentrations at 7.5 ppm and 12.7 ppm, respectively. Even small increase of dissolved oxygen in BFW could lead to promotion of oxygen reduction reaction. Theoretically SA179 tubes operated at pH of 9.75 could lead to formation of bicarbonate and it could protect the tube in absence of dissolved oxygen as evaluated by Molecular Dynamics simulation. However, according to obtained results, tube has been degraded due to presence of dissolved oxygen in BFW. Various contributing factors such as external paint/coat removal, absence of de-aerator system in BFW treatment and improper corrosion inhibitor programme were discussed. Several practical countermeasures have been suggested to mitigate oxygen corrosion failure in petrochemical refineries.

Global Trends in the Research and Development of Petrochemical Waste Gas from 1981 to 2022

As a highly energy-intensive and carbon-emitting industry with significant emissions of volatile organic compounds (VOCs), the petroleum and chemical industry is a major contributor to the global greenhouse effect and ozone layer destruction. Improper treatment of petrochemical waste gas (PWG) seriously harms human health and the natural environment. This study uses CiteSpace and VOSviewer to conduct a scientometric analysis of 1384 scholarly works on PWG and carbon sequestration published between 1981 and 2022, revealing the basic characteristics, knowledge base, research topic evolution, and research hotspots of the field. The results show the following: (1) In the early stages of the petrochemical industry, it was processed tail gas, plant leakage waste gas, and combustion flue gas that were investigated in PWG research. (2) Later, green environmental protection technology was widely studied in the field of PWG treatment, such as biotechnology, catalytic oxidation technology, membrane separation technology, etc., in order to achieve efficient, low energy consumption and low emissions of waste gas treatment, and the number of publications related to this topic has increased rapidly. In addition, researchers studied the internet of things and technology integration, such as the introduction of artificial intelligence, big data analysis, and other technologies, to improve the accuracy and efficiency of exhaust gas monitoring, control, and management. (3) The department has focused on how to reduce emissions by optimizing petrochemical process lines or improving energy efficiency. Emission reduction and low-carbon transition in the petrochemical industry will become the main trend in the future. Switching from renewable carbon to feedstock carbon derived from captured carbon dioxide, biomass, or recycled chemicals has become an attractive strategy to help curb emissions from the chemical industry. The results of our analysis can provide funding agencies and research groups with information to better understand the global trends and directions that have emerged in this field from 1981 to 2022 and serve as a reference for future research.

Evaluation of the performance of air micro-nano bubbles for cleaning in place to reduce the reverse osmosis membrane clogging

This paper investigates the effect of air micro-nano bubbles (AMNBs) on increasing the efficiency of the cleaning in place (CIP) process for reverse osmosis (RO) systems used in petrochemical industries. A membrane from the desalination unit was extracted as the test section over which surface have been formed various types of clogging. The test set-up included, a Lab-Scale Plate-and-Frame Module (LSPFD) accompanied by a micro-nano bubble generator. The ratio of permeate flux and salt rejection in four states before CIP, after conventional CIP, after treatment with AMNBs, and after the conventional CIP along with AMNBs were recorded as 24.4, 26.9, 25.1, 27.3 and 68.2, 77.4, 70.1, 81.8 %, respectively. Scanning Electron Microscopy (SEM) images and Energy Dispersive X-ray Spectrometer (EDS) analysis clearly show a notable reduction in clogging on the membrane when AMNBs are employed. Therefore, cleaning intervals of the industrial RO membranes increase resulting in the extension of their life-span.

Simple building blocks from forestry residues via convergent catalytic pathways

Funneling complex lignocellulose into simple and valuable building blocks has garnered significant interest in the field of biorefinery as a competitor to the petrochemical industry. Reductive Catalytic Fractionation (RCF) of lignocellulose, an innovative biorefinery technology, provides a promising strategy for complete valorization of lignocellulose into various valuable chemicals. In this study, integrated processes utilizing RCF strategies were developed to achieve complete conversion of lignocellulose into various simple and valuable platform chemicals. The core of this system is the flexible use of commercial Ni catalysts including Raney Ni and Ni/SiO2-Al2O3 which brings great benefits for future upscale and industrial applications. Surprisingly, both monomers derived from lignin and high molecular weight fractions could be converted to 4-ethylcyclohexanol while carbohydrate pulp was converted to furfural and 5-methoxymethylfurfural (MMF) in one-pot. MMF could be further upgraded to 2,5-Furandicarboxylicacid (FDCA) via catalytic oxidation by Ru/C catalysts. This work could inspire the development of more sustainable and economically viable biorefinery processes.

Superamphiphobic coating prepared via a two-step spray method: An effective coating for reducing VOCs emission from crude oil tank

In the petrochemical industry, crude oil adhesion in storage tanks leads to volatilization of volatile organic compounds (VOCs), causing environmental harm and economic losses. Superamphiphobic coatings show promise in addressing this issue, but current options face challenges like complexity, limited durability, and poor corrosion resistance. This work introduces a durable and corrosion-resistant superamphiphobic coating on Q235 carbon steel using the "paint + adhesives" two-step spray method. The first layer comprises polytetrafluoroethylene (PTFE) and epoxy resin (E-44), while the second layer consists of fluorine modified silica nanoparticles (F-SiO2). The numerous and homogeneously dispersed fluorine on the coating imparts excellent liquid-repelling properties for both water and crude oil, with a water contact angle of 164.1 ± 2.4° and a sliding angle of 1.1 ± 0.1°, as well as a crude oil contact angle of 172.1 ± 0.9° and a sliding angle of 2.5 ± 0.5°. Systematic stability tests confirm the coating's mechanical and chemical stability, suggesting its potential in practical applications. Importantly, a crude oil tank with our superamphiphobic coating can reduce non-methane hydrocarbon (NMHC) volatilization by 77.4 % ± 7.8 % compared to an uncoated tank. This research provides a superamphiphobic coating to reduce crude oil loss and VOC volatilization in petrochemical enterprises, showing significant contribution to environmental sustainability.

Chlorobenzene oxidation by electrochemical catalysis with La modified Ti/IrO2-Ta2O5

As a typical VOCs emitted from petrochemical industry, chlorobenzene was selected to study its removal by wet oxidation with electrochemical catalysis. Ti based IrO2-Ta2O5 electrode was used in the advanced oxidation of chlorobenzene, and Sn, Sb, Pt and La were used to modify Ti/IrO2-Ta2O5. Ti/IrO2-Ta2O5-La showed the highest removal rate of chlorobenzene and it reached 99.2 % for the chlorobenzene oxidation, which was 20 % higher than those of the other 3 additions. Oxygen evolution overpotential of Ti/IrO2-Ta2O5-La increased to 1.17 V when compared with Ti/IrO2-Ta2O5 of 1.08 V. EPR tests for free radicals and GC-MS tests for intermediates showed that the main active substance was ·OH, and the element Cl in chlorobenzene dissociated from the benzene ring under the action with ·OH to form ·Cl and ClO· radicals. Degradation pathway of chlorobenzene was figured out as chlorobenzene→ phenols→ organic acids→ CO2+H2O.

Construction of dual Z-scheme Ag3VO4–BiVO4/InVO4 photocatalysts using vanadium source from spent catalysts for contaminated water treatment and bacterial inactivation

Vanadate-based photocatalysts have recently attracted substantial attention owing to their outstanding photocatalytic activity for degrading organic pollutants and generating energy via photocatalytic processes. However, the relatively high price of vanadium has hindered the development of vanadate-based photocatalysts for various applications. Spent catalysts obtained from oil refineries typically contain a significant quantity of vanadium, making them valuable for recovery and utilization as precursors for the production of high-value-added photocatalysts. In this study, we transformed the V present in spent catalysts produced by the petrochemical industry into ternary vanadate-based photocatalysts [BiVO4/InVO4/Ag3VO4 (BVO/IVO/AVO, respectively)] designed for water remediation. The ternary composites revealed an enhanced photocatalytic capability, which was 1.42 and 5.1 times higher than those of the binary BVO/IVO and pristine AVO due to the facilitated charge separation. The ternary photocatalysts not only effectively treated wastewater containing various organic dyes, such as methylene blue (MB), rhodamine 6G (R6G), and brilliant green (BG), but also exhibited remarkable photocatalytic performance in the degradation of antibiotics, reduction of Cr(VI), and bacterial inactivation. This paper proposes a feasible route for recycling industrial waste as a source of vanadium to produce highly efficient vanadate-based photocatalysts.