Kinetic, Thermodynamic, and Parametric Studies on Batch Synthesis of 1,1‐Diethoxybutane Catalyzed by Amberlyst‐15 Wet

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Kinetic, Thermodynamic, and Parametric Studies on Batch Synthesis of 1,1-Diethoxybutane Catalyzed by Amberlyst-15 Wet

The reaction of butanal with ethanol in the presence of Amberlyst-15 wet to form 1,1-diethoxybutane, which is a potential diesel additive, was optimized for maximum equilibrium conversion by a parametric study with temperature, reactants ratio, and catalyst loading as factors. Thermodynamic and kinetic studies were also carried out. The kinetic model was validated by means of the experimental data.


Abstract

1,1-Diethoxybutane is a high-potential biofuel additive that enhances various fuel properties, which include cetane number, lubricity, biodegradability, and flash point. This work presents a kinetic and thermodynamic study on the acetalization reaction between butanal and ethanol in the presence of Amberlyst-15 wet in a batch reactor. The experiments were conducted in the temperature range 313–333 K at atmospheric pressure with three different initial molar ratios of reactants and catalyst loadings. An optimal parameter setting to achieve maximum equilibrium conversion of butanal was derived from a parametric study with these three factors. The equilibrium constant for the reaction was determined. Standard thermodynamic properties of the reaction, such as enthalpy, entropy, and Gibbs free energy, were experimentally evaluated. The activity-based two-parameter Langmuir-Hinshelwood-Hougen-Watson rate expression was used for reaction kinetics. The activity coefficients were calculated by the UNIFAC method. The kinetic parameters and the activation energy were evaluated from the experimental data. The experimental data and data predicted by the model were found to be in good agreement.

A Look into the Boil‐Off Gas Reliquefaction in Propane Storage Plants

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A Look into the Boil-Off Gas Reliquefaction in Propane Storage Plants

The reliquefaction process of boil-off gas (BOG) in a propane plant was evaluated by utilizing a reverse Brayton cooling cycle and conducting simulations using Aspen HYSYS software. The operational parameters and system performance were assessed to uncover the key factors influencing BOG generation, energy consumption, and the coefficient of performance of the cycle.


Abstract

The reliquefaction process of boil-off gas (BOG) in a propane plant using the reverse Brayton cooling cycle was examined by simulating the operational parameters and system performance of a propane reliquefaction plant in Aspen HYSYS software. The simulation considered various process and design parameters and their effects on the BOG production rate, energy consumption demand, and coefficient of performance (COP) of the cycle. The results demonstrate that the inclusion of methane in the propane product has a considerable impact on the generation of BOG, but this comes at a cost because power consumption increases significantly and the cycle's COP decreases. Furthermore, heat transmission from the surrounding air through the tank insulation and the temperature at which propane is returned from the jetty influence the BOG generation.

Co‐Pyrolysis of a Binary Blend of Solid Biowastes in a Fixed‐Bed Reactor for Bio‐Oil and Carbon Adsorbent Production

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Co-Pyrolysis of a Binary Blend of Solid Biowastes in a Fixed-Bed Reactor for Bio-Oil and Carbon Adsorbent Production

Co-pyrolyis of a binary mixture of date and cherry seeds was performed in a fixed-bed reactor, optimizing the experimental variables to obtain the maximum liquid fraction yield. The biochar produced was converted into activated carbon. Co-pyrolysis could be a successful means to upgrade the thermal pyrolysis of biowastes.


Abstract

The essential objective of this work was to co-pyrolyze a binary mixture of date and cherry seeds in a fixed-bed reactor. The experimental variables influencing the output of products, such as the pyrolysis temperature, pyrolysis duration, particle size, and heating rate, were optimized. The maximum liquid fraction yield (55.55 % with a bio-oil yield of 29.70 %) was attained at 500 °C for 60 min at a heating rate of 40 °C min−1 and a particle size of 0.25 mm. The Fourier transform infrared and gas chromatography-mass spectrometry results revealed that the bio-oil was predominantly composed of oxygenated hydrocarbons, primarily higher acids (52.05 %), esters (23.67 %), and phenols (13 %). Biochar was converted into activated carbon, which possessed a Brunaer-Emmett-Teller surface area of 1055.55 m2g−1. The amorphous structure of this carbon was confirmed by field emission-scanning electron microscopy and X-ray diffraction measurements.

Photocatalytic Degradation of Ofloxacin in Wastewater Using Mg‐Ni Co‐doped TiO2 Catalyst

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Photocatalytic Degradation of Ofloxacin in Wastewater Using Mg-Ni Co-doped TiO2 Catalyst

Residual pharmaceuticals can pose a threat to the aquatic ecosystem. Mg-Ni co-doped TiO2 was prepared by wet impregnation, characterized by various methods, and used as a photocatalyst for degradation of the antibiotic ofloxacin (OFX) under solar irradiation, which has potential applications in water treatment and environmental remediation. The optimal conditions for OFX degradation were determined.


Abstract

This study focuses on the preparation and characterization of Mg-Ni co-doped TiO2 and its application in the degradation of the pharmaceutical ofloxacin (OFX) under solar irradiation. A wet impregnation method was used to prepare Mg-Ni co-doped TiO2. Characterization, optimization, and kinetic studies revealed that the doped TiO2 material is effective in degrading OFX, with potential applications in water treatment or environmental remediation processes. Ultraviolet diffuse reflectance spectroscopy indicated that the band gap of TiO2 was reduced due to doping with Mg and Ni. A reduced band gap can enhance the material's photocatalytic properties, which is important for its application in solar-driven degradation processes. The catalyst dose and OFX concentration for the degradation process were optimized. A catalyst dose of 2 g L−1 and an OFX solution with a concentration of 40 ppm, maintained at pH 5, resulted in the highest degradation efficiency. The degradation process followed first-order kinetics, suggesting that the rate of degradation increased with increasing doping.

Thermodynamics of Reversible Hydrogen Storage: Are Methoxy‐Substituted Aromatics better through Oxygen Functionality?

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Thermodynamics of Reversible Hydrogen Storage: Are Methoxy-Substituted Aromatics better through Oxygen Functionality?

Substitution of pyridine and quinoline with methoxy groups on the ring has been investigated thermodynamically regarding their applicability as liquid organic hydrogen carrier materials. The thermochemical properties of methoxy-substituted pyridines and quinolines and their respective hydrogenated counterparts have been analyzed from a thermodynamic point of view.


Abstract

An attractive option for the storage of hydrogen is the reversible hydrogenation of an aromatic substance, a so-called liquid organic hydrogen carrier. For hydrogen release, it is desirable to find substances with low enthalpies of reaction for dehydrogenation. It has been demonstrated that substitution, e.g., with methyl groups, on the ring can have a positive effect in this regard. In this study, thermochemical properties of methoxy-substituted pyridines and quinolines and their respective hydrogenated counterparts have been analyzed from a thermodynamic point of view. Combustion calorimetry has been utilized to measure the enthalpy of formation and the transpiration method for determining the vapor pressure. Additionally, high-level quantum-chemical approaches have been applied to obtain caloric data in the gas phase, which provide a basis for comparison and evaluation of the experimental data. The results reveal two main effects of methoxy substitution. First, oxygenated substituents like methoxy groups have stronger effect on the Gibbs energy of reaction and thus the temperature needed thermodynamically for hydrogen release than methyl groups. Second, the effect is highly depending on the position of the substitution on the ring. Particularly methoxy groups close to a N heteroatom can have a significant positive effect, which might enable hydrogen release at equilibrium temperatures more than 50 K lower than for their unsubstituted analogue.

A Comprehensive Workflow towards More Equant‐Shaped Crystals of Active Pharmaceutical Ingredients

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A Comprehensive Workflow towards More Equant-Shaped Crystals of Active Pharmaceutical Ingredients

A miniaturized multi-reactor system and knowledge-based workflow were developed to identify optimal process conditions for controlling the crystal morphology of active pharmaceutical ingredients (APIs). This method, which features minimal material usage, inline imaging, and independent control of temperature T and supersaturation S, can be used to obtain more equant-shaped crystals of diverse APIs.


Abstract

The morphology of crystalline active pharmaceutical ingredients (APIs) can significantly affect their product properties, so that its control during manufacturing is crucial. To address this, a newly augmented commercial milliliter-scale facility and knowledge-based workflow were developed with the aim of identifying optimal process conditions for producing more equant-shaped crystals. The design includes minimal material usage, inline imaging, and independent temperature and supersaturation control through evaporative crystallization. The methodology enables the identification of process conditions for equant-shaped crystals across diverse APIs. These findings contribute to advancing pharmaceutical research and development by providing a reliable approach to optimize crystal morphology.

The Effect of Size and Morphology on the Antibacterial Activity of Zn‐loaded LTL Nanozeolite

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The Effect of Size and Morphology on the Antibacterial Activity of Zn-loaded LTL Nanozeolite

LTL nanozeolites with spherical-like and disk-shaped morphologies were synthesized by exploiting the effect of the alumina source, and the effect of size and morphology on the antibacterial activity of Zn-loaded LTL nanozeolites was studied. Spherical-like LTL nanozeolite showed higher antibacterial activity due to its larger surface area resulting in higher loading of Zn ions as antibacterial agent.


Abstract

A simple and cost-effective approach was used to synthesize different morphologies of Linde Type L (LTL) nanozeolite. The resulting products were characterized by techniques such as X-ray diffraction, Fourier transform infrared spectroscopy, scanning electronic microscopy, and Brunauer-Emmett-Teller measurements. The results showed that LTL nanozeolite was successfully synthesized, and different morphologies, including spherical-like and disk-shaped nanoparticles, were obtained. Then, the effect of size and morphology on the antibacterial activity of the obtained products was studied. Spherical-like LTL nanoparticles showed higher antibacterial activity due to their larger pore volume and surface area and higher loading of biocidal zinc cations.

A Review on Virgin or Waste Polymers in Bitumen Modification for Ageing and Rejuvenation

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A Review on Virgin or Waste Polymers in Bitumen Modification for Ageing and Rejuvenation

This review describes the various possible polymers used for bitumen modification and explores the advantages and disadvantages of different waste polymers utilized in bitumen modification due to environmental concerns. It focuses on the challenges in the production of high-quality bitumen with improved performance as per the BIS, IRC, and SHRP specifications.


Abstract

The physicochemical behavior of polymer-modified binders suggests suitability for rejuvenating aged pavements and meets base bitumen parameters. The strengthening effect is mainly due to their electronic structures, which interact with asphaltene via CH-π interactions and crosslinkage reaction with S–H and O–H bonds of base bitumen, along with the virgin and waste polymers used. The functional groups in bitumen play a vital role in enhanced paving resistance after modification. This review aims to provide an overview of the current knowledge on the role of polymers in bitumen modification and to identify research gaps. It also discusses underutilized technologies, methods, and future research perspectives to implement more effective road networks for an environmentally sustainable development.

A Comprehensive Parametric Study on CO2 Removal from Natural Gas by Hollow Fiber Membrane Contactor: A Computational Fluid Dynamics Approach

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A Comprehensive Parametric Study on CO2 Removal from Natural Gas by Hollow Fiber Membrane Contactor: A Computational Fluid Dynamics Approach

A hollow fiber membrane contactor was modeled to find the ideal conditions for removing CO2 from natural gas. The effects of liquid flow rate, gas flow rate, and absorbent concentration were studied for three different absorbents (ethylenediamine, monoethanolamine, and piperazine). In general, using piperazine as absorbent resulted in the highest CO2 capture efficiency across all investigations.


Abstract

This study examined essential factors in the use of hollow fiber membranes that affect CO2 removal efficiency. In the simulation, a finite element model for a membrane with ten fibers was used. Each fiber is 175 mm long with inner radius of 0.75 mm and outer radius of 1.5 mm. Liquid and gas flow rates were set at 100–800 mL min−1, and adsorbent concentration was adjusted in the range of 200–1500 mol m−3 for monoethanolamine, piperazine (PZ), and ethylenediamine absorbents. Increasing the liquid flow rate, gas flow rate, and absorbent concentration leads to an increase, decrease, and increase in efficiency, respectively. Thus, using PZ as absorbent with a concentration of 1080 mol m−3 liquid and gas flow rates of 400 and 180 mL min−1, respectively, showed a CO2 removal efficiency of > 95 % for a membrane effective length of 0.3 m.

Operating Behavior of Pulse Jet‐Cleaned Filters Regarding Energy Demand and Particle Emissions – Part 2: Modeling

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Operating Behavior of Pulse Jet-Cleaned Filters Regarding Energy Demand and Particle Emissions – Part 2: Modeling

The operating behaviour of a pulse jet-cleaned filter is calculated applying and adapting model equations, demonstrating the trade-off between energy demand and particle emissions.


Abstract

Baghouse filters applied for gas cleaning are subject to digitalization concepts, including process modeling and the development of digital twins in order to improve energy efficiency and lower particle emissions. Modeling equations from literature were adapted to match experimental data from part 1 of this study to calculate the effect of varying filter face velocities, dust concentrations, or tank pressures on energy demand and particle emissions. Based on the model approaches, an operation curve that enables the evaluation of filter operation regarding the trade-off between energy demand and particle emissions can be constructed. The identification of energetically optimal cycle times and favorable operation regions is possible due to the extensive experimental framework of the model.