Performance Analysis of Silica Fluidized Bed Membrane Reactor for Hydrogen Production as a Green Process Using CFD Modelling.

The main aim of this study deals with the potential evaluation of a fluidized bed membrane reactor (FBMR) for hydrogen production as a clean fuel carrier via methanol steam reforming reaction, comparing its performance with other reactors including packed bed membrane reactors (PBMR), fluidized bed reactors (FBR), and packed bed reactors (PBR). For this purpose, a two-dimensional, axisymmetric numerical model was developed using computational fluid dynamics (CFD) to simulate the reactor performances. Model accuracy was validated by comparing the simulation results for PBMR and PB with experimental data, showing an accurate agreement within them.

Preparation and characterization of bio-waste derived chitosan/hydroxyapatite/pectin green biocomposite.

This study focuses on the synthesis and structural analysis of biocomposites comprising chitosan (Cs), hydroxyapatite (HA), and pectin (Pe). Cs was extracted from shrimp skin, HA from bovine teeth and bones, and Pe from orange peel and apple. The biocomposites were prepared via a freeze-drying method using glutaraldehyde (GA) as a cross-linking agent.

Synthesis, characterization, experimental design and process analysis of heavy metals adsorption on a wheat straw based amidoximated bioadsorbent.

In this research, 3-(trimethoxysilyl)propyl methacrylate (MPS) silane agent was applied to modify the extracted wheat straw (WS) cellulose as a natural biopolymer. Polyacrylonitrile (PAN) was attached to the MPS-modified WS (MPS-WS) via in-situ polymerization to form PAN-WS biocomposite. AO-WS amidoximated biocomposite adsorbent was synthesized through amidoxime reaction and the effects of different parameters including agitation speed, metal ion concentration, and adsorbent dosage on its efficiency of Pb(II) removal were investigated using the Taguchi experimental design method.

Experimental study on evaluation and optimization of heavy metals adsorption on a novel amidoximated silane functionalized Luffa cylindrica.

This study aimed to synthesize an amidoximated Luffa cylindrica (AO-LC) bioadsorbent, and evaluate its efficiency in the adsorption of heavy metals from the aqueous solutions. For this purpose, NaOH solution was used to alkaline treatment of Luffa cylindrica (LC) fibers. The silane modification of LC was performed using 3-(trimethoxysilyl)propyl methacrylate (MPS).

Application of TOPSIS algorithm in describing bacterial cellulose-based composite hydrogel performance in incorporating methylene blue as a model drug.

A multi-component hydrogel was developed using bacterial cellulose, alginate, and gelatin with the aid of glycerol as trihydric alcohol which participates in re-distribution of hydrogen bonds in the test system. FTIR, XRD, SEM, and TGA as instrumental techniques were used to structurally characterize the physical/chemical properties of the formed composite hydrogel. By using an exponential equation, swelling behavior of the hydrogel was evaluated.

Performance Comparison of Polymeric and Silica-Based Multi-Bed Pervaporation Membrane Reactors during Ethyl Levulinate Production.

A detailed numerical study of ethyl levulinate (EtLA) production with levulinic acid (LA) and ethanol (Et) in a multi-bed traditional reactor (MB-TR) and a silica-based and polymeric multi-bed pervaporation membrane reactors (MB-PVMR) was conducted and the efficiency of each design was studied under different operation conditions. Due to water production in the EtLA production process, water removal by a pervaporation system may improve process performance. Our results showed that MB-PVMR had higher performance compared with MB-TR.

A Theoretical Analysis on a Multi-Bed Pervaporation Membrane Reactor during Levulinic Acid Esterification Using the Computational Fluid Dynamic Method.

Pervaporation is a peculiar membrane separation process, which is considered for integration with a variety of reactions in promising new applications. Pervaporation membrane reactors have some specific uses in sustainable chemistry, such as the esterification processes. This theoretical study based on the computational fluid dynamics method aims to evaluate the performance of a multi-bed pervaporation membrane reactor (including poly (vinyl alcohol) membrane) to produce ethyl levulinate as a significant fuel additive, coming from the esterification of levulinic acid.

Recent Progresses in Application of Membrane Bioreactors in Production of Biohydrogen.

Biohydrogen is a clean and viable energy carrier generated through various green and renewable energy sources such as biomass. This review focused on the application of membrane bioreactors (MBRs), emphasizing the combination of these devices with biological processes, for bio-derived hydrogen production. Direct biophotolysis, indirect biophotolysis, photo-fermentation, dark fermentation, and conventional techniques are discussed as the common methods of biohydrogen production.

Experimentation and CFD modeling of continuous degradation of formaldehyde by immobilized Ralstonia eutropha in a semi-pilot-scale plug flow bioreactor.

This study focuses on continuous formaldehyde (FA) biodegradation by Ralstonia eutropha immobilized on polyurethane foam in a semi-pilot-scale plug flow packed-bed bioreactor. The stepwise increasing of the influent FA concentration from 43.9 to 1325.

Photocatalytic Degradation of p-Nitrophenol in an Annular Column Photoreactor and the Intermediates.

The photocatalytic degradation of p-nitrophenol using a titanium dioxide suspension was studied in an annular column photoreactor operating in batch recycle mode with an aerated reservoir tank. The dependency of the process efficiency on the initial PNP concentration was quantitatively defined using an exponential function. The degradation rate was highest at pH 7-7.

Use of a packed-bed airlift reactor with net draft tube to study kinetics of naphthalene degradation by Ralstonia eutropha.

Biodegradation of naphthalene by Ralstonia eutropha (also known as Cupriavidus necator) in a packed-bed airlift reactor with net draft tube (PBALR-nd) was studied; the Kissiris pieces were the packing material. The reactor hydrodynamics has been characterized under abiotic conditions and the dependencies of the superficial gas velocity (U G) on the gas holdup (εG), liquid mixing time, and mass transfer coefficient were determined. The improving role of the net draft tube in this small column reactor (height 42 cm, ID 5 cm) was confirmed.