Batch System Research Articles

A Review on Catalytic Ethanol Synthesis via Hydrogenation of Carbon Dioxide.

The catalytic hydrogenation of carbon dioxide (CO2) is a promising strategy for mitigating greenhouse gas emissions while generating sustainable fuels and valuable chemicals. Among potential products, ethanol stands out as a renewable energy carrier due to its compatibility with existing fuel infrastructure and ability to reduce CO2 emissions when integrated into energy systems. Despite the success in converting CO2 into C1-Chemicals with high yields, the selective conversion of C2+ products, including ethanol, remains a challenge due to the synthetic complexity. This review explores recent advances in CO2 hydrogenation to ethanol, emphasizing the catalytic performance of noble metals (e.g., Rh, Pd, Au, Ir, Pt) and non-noble metals (e.g., Co, Cu, Fe) catalysts. Mechanistic insights into CO2 conversion and the role of metal active sites in governing selectivity and by-product formation are addressed. A critical balance between reductive and C-C coupling steps for achieving high ethanol yields is highlighted, supported by thermodynamic analyses. Experimental results from batch and continuous-flow reactor systems are discussed. Challenges such as low selectivity and by-product formation are analyzed alongside strategies to address them, including advanced catalyst designs. This review outlines future research directions for catalyst development and the potential industrial application of CO2 hydrogenation to ethanol.

Removal of Ni2+ and Cd2+ from aqueous solutions by bionanosorbents: Isotherm, thermodynamic and mechanistic studies.

Removal of Ni2+ and Cd2+ from aqueous solutions by bionanosorbents: Isotherm, thermodynamic and mechanistic studies.

Continuous-flow phosphate removal using Cry-Ca-COS Monolith: Insights from dynamic adsorption modeling.

Continuous-flow phosphate removal using Cry-Ca-COS Monolith: Insights from dynamic adsorption modeling.

Maximizing aromatic hydrocarbon production through catalytic pyrolysis of lignocellulosic residues over ZSM-5 zeolite using both batch and continuous reaction systems.

Maximizing aromatic hydrocarbon production through catalytic pyrolysis of lignocellulosic residues over ZSM-5 zeolite using both batch and continuous reaction systems.

Immobilization of Inorganic Phosphorus on Soils by Zinc Oxide Engineered Nanoparticles

The overuse of inorganic phosphate fertilizers in soils has led to the transfer of inorganic phosphorus (Pi) to aquatic ecosystems, resulting in eutrophication. Adsorption–desorption studies in batch systems were used to evaluate the effect of adding 1% zinc oxide (ZnO) engineered nanoparticles (ENPs) on Pi retention in Ultisol, and Mollisol soils. The 1% ZnO–ENPs showed increased chemical properties such as pH, electrical conductivity, and organic matter content, and reduce nutrient bioavailability (P, N, and Zn), and physical properties such as surface area and pore size of the two soils. The kinetic data of Pi adsorption on Ultisol, Mollisol, Ultisol + 1% ZnO–ENP, and Mollisol + 1% ZnO–ENP systems fitted well to the pseudo-second-order model (r2 ≥ 0.942, and χ2 ≤ 61), and the Elovich model (r2 ≥ 0.951, and χ2 ≤ 32). Pi adsorption isotherms for the Ultisol soil adequately fitted to the Freundlich model (r2 = 0.976, and χ2 = 16), and for the Mollisol soil, the Langmuir model (r2 = 0.991, and χ2 = 3) had a better fit to the data. With 1% ZnO–ENPs, the linear, Langmuir, and Freundlich models correctly described the Pi adsorption data. Pi desorption was reduced in the Ultisol compared to the Mollisol soil, and with 1% ZnO–ENPs further decreased Pi desorption in both soils. Therefore, ENPs can be used as a new alternative material for Pi fixation in agricultural soils and contribute to mitigating eutrophication issues of aqueous systems.

Comparison of TiO2 Thin Film Photocatalytic and Enhanced Photo‐Fenton's Detector for Wastewater Treatment from Power Plants

AbstractWastewater treatment is considered one of the recent solutions to water shortages if the water is treated efficiently and reaches clean water standards. Here, three advanced oxidation processes, namely the Fenton process, photo‐Fenton process, and photocatalytic TiO2 NPs thin film were studied in an attempt to reduce chemical oxygen demand (COD) and oil content from power plants’ wastewater using a batch system set‐up. In order to identify the optimum running conditions for Fenton and photo‐Fenton processes, different parameters were studied for each process, including pH, H2O2 concentration, and Fe+2 concentration. The findings showed that a pH value of 3 was the optimum for the Fenton processes, and for the H2O2 and Fe+2 concentrations, the values were 0.5 mL/L and 0.65 g/L, respectively, in a reaction time range of 0–240 min. However, the photo‐Fenton process gave a maximum COD removal ratio of 97.41%, while photocatalytic by nano thin film gave about 61.4%. The reported removal ratios were estimated after finishing the total reaction time, 240 min.

ADSORPTION OF CONGO RED DYE ON ACTIVATED GRAPHITE AND ITS COMPOSITE, AN ISOTHERMAL AND THERMODYNAMIC STUDY

Water pollution with dyes is one of the major risks that threaten the environment as a result of the development of industry and the increase in human need for it. In order to address the problem of pollution, many methods have been used, including adsorption through the use of nanomaterials and their compounds as adsorbent surfaces. This study includes the oxidation of graphite and the preparation of nano-titanium dioxide. Chemically, their composition was prepared. The prepared materials were characterized using Fourier transform infrared and X-ray diffraction techniques. The effect of factors (adsorbent surface weight, equilibrium time, initial concentration, and temperature) on the process of adsorption of Congo Red dye onto activated graphite and its composites was studied through the batch system. The equilibrium data were analyzed using more than one adsorption isotherm model, and it was found that it follows the Freundlich isotherm model for both. Activated graphite and its composites. The thermodynamic functions of the adsorption process were also studied and found to be spontaneous, less regular, and endothermic in nature

REMOVAL OF AMOXICILLIN FROM AQUEOUS SOLUTIONS USING MODIFIED BENTONITE

The objective of this study is to modify Iraqi natural bentonite (NB), a readily accessible and low-cost raw material, using various techniques and to explore the possible use of it as an adsorbent for the elimination of amoxicillin (AMX) from aqueous solutions through batch system studies. Chemical and physical processes were used to create the modified bentonite (MB): (1) NB was mixed with cationic surfactants (long and short alkyl chain surfactants), and (2) heat activation created calcined bentonite. The synthesized MB is characterized by surface area, "scanning electron microscopy" (SEM), and "Fourier transform infrared spectroscopy" (FTIR). There are many variables that affect how much AMX is eliminated, such as contact time, pH of solution, rate of agitation, initial concentration, and dose of the sorbent. The results showed that the Freundlich and pseudo-second-order models fit the experimental data better, with maximal removal efficiencies for calcined, long, and short alkyl chain modified natural bentonite being 94%, 70%, and 96%, respectively. The results of the trials showed that the modifications improved NB's capacity to extract AMX from aqueous media.

MODIFICATION OF ALUM SLUDGE AS ADSORBENT FOR REMOVAL OF RHODAMINE-B DYE IN WATER

Water treatment plants (WTP) in Indonesia generally use a physical-chemical process that generates a massive volume of sludge as waste. This sludge is typically discharged into the river without sufficient treatment due to land availability and/or treatment cost constraints. Aim: This study aimed to recycle the alum sludge from a drinking water treatment plant as an adsorbent for removing dye from wastewater. Methodology and results: Alum sludge was activated by several methods including calcination at 400oC and 600oC (AS-CAL400 and AS-CAL600), gelation (AS-GEL), synthesis of TiO2-alum sludge composites (TiO2@AS), and synthesis of ZnCl2-alum sludge composites (ZnCl2@AS). The adsorbents were characterized by SEM-EDS, XRF, BET, and pHPZC. The adsorption assays were carried out in a batch system and used synthetic wastewater containing Rhodamine-B dye as a model contaminant. The result shows that the highest dye removal of up to 87% was obtained using ZnCl2@AS adsorbent, contact time of 2 hours, the adsorbent concentration of 3 g/L, initial dye concentration of 50 mg/L, and pH 2. Conclusion, significance and impact study: The conclusion shows that recycled alum sludge, especially when activated with ZnCl₂, is highly effective for removing Rhodamine B dye from wastewater. It achieved 87% removal efficiency and 26 mg/g adsorption capacity under optimal conditions. The adsorbent has a rough surface with a 128.60 m²/g area, and its adsorption behavior follows the Freundlich isotherm and pseudo-second-order kinetics. Further research including long-term use, and application in real dye wastewater should be conducted to evaluate the feasibility of this adsorbent.

Removal of Brilliant Blue R and Victoria Blue R dyes from textile wastewater by adsorption method using pomegranate peel

This study investigated the removal of Brilliant Blue R (BBR) and Victoria Blue R (VBR), commonly used dyes in the textile industry, from wastewater using the pomegranate peel with an adsorption method. Pomegranate peel was characterized by using X-ray diffraction (XRD), Brunauer, Emmet ve Teller (BET), scanning electron microscopy (SEM), Fourier transform infrared spectrophotometer (FT-IR), thermogravimetric analysis (TGA), and zeta potential. For both dyes, pH, adsorbent amount, contact time, salt effect, and wastewater parameters were investigated in the batch system, while adsorbent amount and flow rate parameters were investigated in the continuous system. The adsorption results of both dyes on pomegranate peel indicate that they fit the pseudo-second-order kinetic model. The adsorption isotherms of both dyes were found to be compatible with the Langmuir isotherm model. In the thermodynamic study, it was determined that the adsorption process was spontaneous (∆G°<0) and exothermic (∆H°<0). It was decided that pomegranate peel is a suitable adsorbent for the adsorption of BBR and VBR dyes. Finally, the adsorption yields for removing BBR and VBR from wastewater using pomegranate peel were 90.38% and 100%, respectively. This result shows that the high adsorption efficiency obtained for both dyes makes it possible for pomegranate peel to be widely applied as an adsorbent in wastewater treatment.

Developing a Model that Enables Real Time Streaming of Transactions in Financial Institutions Case Study: Bank of Kigali PLC

Recent technological advancements, particularly in banking and financial services, have profoundly influenced the development and use of applications. The increasing demand for modern banking systems to address consumer expectations, speed up market entry, enhance user experiences, improve security, and optimize system efficiency has led to the adoption of new technologies. This trend has sparked the creation of numerous banking-specific modernization solutions. Within the interconnected banking, financial services, and insurance (BFSI) sectors, the need for effective enterprise application integration (EAI) is crucial for gaining both technological and business advantages. Real-time data streaming through technologies like Apache Kafka has become essential for enabling seamless communication between systems. Kafka, a widely used distributed streaming platform, surpasses traditional message queues in scalability, message retention, data replication, and processing order, making it an essential part of modern banking systems. Unlike batch processing, which processes large volumes of data at set intervals and can cause delays in transactions, streaming technologies eliminate lag by processing data continuously in real-time, significantly enhancing the speed and accuracy of financial operations. The shift from batch systems to real-time streaming allows BFSI applications to process transactions and settlements more quickly, reducing processing times and improving operational efficiency. Additionally, the use of Kafka enhances the security and reliability of data transfers, making it a valuable tool for modernizing banking infrastructures. Therefore, integrating real-time streaming technologies like Kafka not only improves system performance but also boosts security, scalability, and operational effectiveness, enabling financial institutions to better meet customer demands in an increasingly digital economy.

ADSORPTION OF METHYLENE BLUE DYE FROM AQUEOUS SOLUTION USING BIO-WASTE POPLAR FIBER

Poplar fiber corresponds to the seed hairs of the Populus genus trees and is a naturally abundant lignocellulosic fiber with the features of thin-walled large lumen, lightweight and hydrophobic properties. Based on the structure and properties exhibited by poplar fiber nominate it as a highly favored adsorbent material for cationic dyes. This study aims to determine the adsorption efficiency for methylene blue (MB) dye with chemically enhanced poplar fibers and compare its capacity with milkweed fibers. Prior to adsorption experiments, the fibers were treated with NaOH solution to remove the wax coating attached on the fiber surface. Adsorption studies were performed in a batch system using dye solution with initial dye concentration of 50 mg L-1 . The adsorbent dosage was evaluated at 10 g L-1 amount, with contact time of 3 h and without pH adjustment. After the experiments, the remaining dye concentration in liquid was quantified in UV-Vis spectrophotometry. The results revealed that poplar fiber exhibited higher adsorption capacity compared with milkweed fiber. Poplar fibers were efficient to decolorize MB dye solution, reaching a higher color removal percentage than milkweed fibers. It can be concluded that poplar fibers were alternative adsorbents for removing cationic dyes due to their hollow structure.

Microfluidic rapid isolation and electrochemical detection of S. pneumonia via aptamer-decorated surfaces.

Microfluidic rapid isolation and electrochemical detection of S. pneumonia via aptamer-decorated surfaces.

Selective Toluene Oxidation Using Sulfur-Doped Polymeric Carbon Nitride Photocatalysts.

Selective traditional oxidation of toluene to high-value products like benzyl alcohol, benzaldehyde, and benzoic acid faces significant challenges due to high dissociation energy requirements, harsh reaction conditions, and complex product distributions. While photocatalysis using O2 as an oxidant offers a green alternative, developing efficient and durable photocatalysts for selective oxidation in both batch and flow systems remains challenging. Here, sulfur-doped polymeric carbon nitride (S-CN) is demonstrated as a versatile photocatalyst for selective toluene oxidation, applicable in both powder form and as binder-free panels across various reactor configurations and solvents. Tuning S monomer content within supramolecular assemblies that serve as S-CN precursors, allows enhanced light absorption, optimized band positions, high specific surface area, and tailored structural properties of the ensuing catalysts. The optimized photocatalyst achieves high product selectivity, yielding ∼72% benzaldehyde and ∼26% benzoic acid after 24 h. Mechanistic studies confirm the concurrent oxidation and reduction reactions occurring and the roles of O2 · - and 1O2. Extended reaction time (48 h) enables selective benzoic acid production (73.4%) with minimal benzaldehyde formation (<1%), demonstrating excellent product control.

Thraustochytrium sp. and Aurantiochytrium sp.: Sustainable Alternatives for Squalene Production.

This study investigated a sustainable alternative to squalene production utilizing Thraustochytrium sp. and Aurantiochytrium sp., thereby reducing dependence on critically endangered sharks exploited for this compound. By optimizing fed-batch cultivation, a technique prevalent in industrial biotechnology, we have enhanced squalene yields and have demonstrated, through sensitivity analysis, the significance of this shift in preserving species at risk of extinction. Optimization of culture conditions led to the highest biomass concentrations for Thraustochytrium sp. being achieved at lower C-N ratios (<5.0), while the optimal biomass production for Aurantiochytrium sp. occurred in culture media with a high C-N ratio of 54:50. Regarding squalene production, Thraustochytrium sp. produced 26.13 mg/L in the fed-batch system after 72 h, and Aurantiochytrium sp. produced 54.97 mg/L in a batch system with 30 g/L glucose and 0.22 g/L nitrogen after 96 h, showcasing their potential for industrial applications. Moreover, the sensitivity analysis revealed that, on an industrial scale, both strains could produce up to 59.50 t of squalene annually in large-scale facilities, presenting a valuable and sustainable alternative for the biotechnological industry and significantly reducing the reliance on non-renewable and endangered sources such as shark liver oil and preventing the annual capture of over 156,661 sharks.

Efficient Removal of Cu(II) from Wastewater Using Chitosan Derived from Shrimp Shells: A Kinetic, Thermodynamic, Optimization, and Modelling Study

Chitosan was hydro-thermally extracted from grey shrimp carapaces and characterized using various techniques (degree of deacetylation (DD), viscosity, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and surface area analysis (BET)). It was then used for Cu(II) removal in a batch system, achieving a maximum capacity of 89 mg/g under standard conditions. Both pseudo-first-order and pseudo-second-order nonlinear kinetic models described the adsorption of Cu(II) ions on chitosan well, with a better fit of the pseudo-first-order model at low concentrations, while the equilibrium data suggested that the Langmuir model was suitable for describing the adsorption system, with a maximum adsorption capacity of 123 mg/g. A response surface methodology and central composite design were used to optimise and evaluate the effects of six independent parameters: initial Cu(II) concentration, pH, chitosan concentration (S/L), temperature (T), contact time (t), and NaCl concentration on the adsorption efficiency of Cu(II) by the synthesised chitosan. The proposed model was confirmed to accurately describe the phenomenon within the experimental range, achieving an R2 value of 1. ANOVA indicated that the initial concentrations of Cu(II) and chitosan concentration (S/L) were the most significant factors, while the other variables had no significant effect on the process. The adsorption capacity of Cu(II) onto the prepared chitosan was also optimised and modelled using artificial neural networks (ANNs). The maximum amount, qmax = 468 mg·g−1, shows that chitosan is a highly effective adsorbent, chelating and complexing for copper ions.

Unveiling the Role of Rhenium Precursors in Supercritical CO₂ Hydrogenation: A Comparative Study of ReOx/TiO₂ Catalysts

AbstractHeterogeneous rhenium catalysts supported on various oxides, particularly TiO2, have demonstrated effectiveness in converting carbon dioxide (CO2) to methanol via hydrogenation, showing high selectivity under diverse reaction conditions. However, the impact of different rhenium precursors on the catalytic performance and physicochemical properties of ReOx/TiO2 has not yet been elucidated. Herein, we compared catalysts prepared from NH4ReO4 and Re2O7 precursors with varying rhenium content (4–14 wt% Re) synthesized using a wet impregnation approach. These catalysts were evaluated under different reaction temperatures (200–250 °C), pressures (100–200 bar), and H2/CO2 ratios (1–4). This study revealed that both catalytic performance and physicochemical properties varied not only with the type of precursor but also with the rhenium content. Variation in reduction temperature, particle size, oxidation states of Re and surface Re═O terminals were observed. In batch system, catalysts derived from NH4ReO4 demonstrated a higher selectivity for methanol production under high pressure and stoichiometric conditions, regardless of temperature. In contrast, Re₂O₇‐based catalysts demonstrated higher methanol selectivity at 200 °C, with H₂/CO₂ ratios between 1 and 3, regardless of the total pressure. These findings provide a deeper and valuable insight on the choice of precursors for the preparation of ReOx/TiO2 catalysts for CO2 hydrogenation.

Silica‐Embedded Metal Oxide Nanoparticles as Epoxidation Catalysts: Batch and Continuous Flow Systems

AbstractCatalytic epoxidation of olefins gives epoxide chemicals for several end‐user products. With the technological advancements of these processes (especially for light olefins), which have importantly contributed to the epoxides market expansion, challenges remain in developing adequate heterogeneous catalysts for converting bulkier olefins, using simple catalyst synthesis procedures, and, on the other hand, studying the catalytic performances under different operation modes. Hence, heterogeneous epoxidation catalysts are prepared via simple one‐pot procedures, with the necessary versatility to tune the material properties for batch and continuous flow operation. Specifically, silica‐embedded nanoparticles of molybdenum oxide (Si/Mo(x), x = Mo loading) and silica‐embedded nanoparticles of binary transition metal oxides (Si/MoM, M = Ta, Nb or W) are synthesized, and promoted the epoxidation of cis‐cyclooctene with tert‐butylhydroperoxide as oxidant, at 70 °C. Epoxide yields in the range of 90%–100% are reached within 4 h, at 70 °C, under batch operation. Under continuous flow, steady state conditions (fixed bed reactor), catalyst Si/MoNb led to ca. 44% epoxide yield, at 70 °C. At 90 °C, Si/MoNb exhibited multifunctionality leading to 51% cyclooctanone yield. It represents the first fully inorganic heterogeneous Mo‐catalyst for continuous flow olefin epoxidation and the first heterogeneous Mo‐catalyst for integrated olefins‐to‐cycloalkanones with hydroperoxides.

Growth performance of Scenedesmus sp. AQUAMEB-57. Ankistrodesmus sp. AQUAMEB-33, and Synechococcaceae AQUAMEB-32 cultivated at different light intensities

ABSTRACT Increasing air pollutants significantly contributes to climate change, requiring innovative mitigation strategies. Microalgae provide a promising solution by absorbing CO₂ and pollutants like nitrogen oxides (NOx), sulfur oxides (SOx), and ammonia from agricultural and industrial emissions, while also generating biomass for biofuels and animal feed. This study investigated the effects of light intensity on the growth and biochemical composition of Scenedesmus sp. AQUAMEB-57, Ankistrodesmus sp. AQUAMEB-33, and Synechococcaceae AQUAMEB-32 cultivated in photobioreactors under two batch and continuous culture conditions. Scenedesmus sp. reached the highest cell concentration (8 × 106 cells ml−1) at 200 µmol photons m−2s−1, while Ankistrodesmus sp. and Synechococcaceae peaked at 300 µmol photons m−2s−1. Dry biomass was highest for all species at 300 µmol photons m−2s−1 . Scendesmus sp showed the highest protein content (15.6%) at a light intensity of 200 µmol photons m−2s−1, Ankistrodesmus sp. (17.2%) at 300 µmol photons m−2s−1, and Synechococcaceae (23.5%) at 100 µmol photons m−2s−1. Maximum carbohydrate content for Scenedesmus sp., Ankistrodesmus sp., and Synechococcaceae was 56.0%, 20.5%, and 18.4%, respectively, at 300 µmol photons m−2s−1. C16/C18 fatty acids significantly increased as light intensity was raised from 100 to 200 µmol photons m−2s−1. The findings show that light intensity impacts growth rates and biochemical profiles, varying by species and cultivation mode. Continuous systems yield higher biomass than batch systems, emphasizing the need for optimized strategies to enhance algal productivity. This research enhances understanding of microalgal growth dynamics, offering insights into optimizing conditions for improved biomass yield and supporting sustainable biofuel production and other valuable products.

AUDITOR

Increasing computing demands and concerns about energy efficiency in high-performance and high-throughput computing are driving forces in the search for more efficient ways to use available resources. Sharing resources of an underutilised cluster with a high workload cluster increases the efficiency of the underutilised cluster. The software COBalD/TARDIS can dynamically and transparently integrate and disintegrate such resources. However, sharing resources also requires accounting. AUDITOR (Accounting Data Handling Toolbox for Opportunistic Resources) is a modular accounting ecosystem that is able to cover a wide range of use cases and infrastructures. Accounting data are gathered via so-called collectors, which are designed to monitor batch systems, COBalD/TARDIS, cloud schedulers, or other sources of information. The data is stored in a database, and access to the data is handled by the core component of AUDITOR, which provides a REST API along both Rust and a Python client libraries. So-called plugins can take actions based on accounting records. Depending on the use case, one simply selects a suitable collector and plugin from a growing ecosystem of collectors and plugins. To facilitate the development of collectors and plugins for yet uncovered use cases by the community, libraries for interacting with AUDITOR are provided.