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Biodiesel from waste oil is produced using heterogeneous catalyzed transesterification in a fixed bed reactor (FBR). Potassium iodide/calcium oxide/alumina (KI/CaO/Al2O3) catalyst was prepared through the processes of calcination and impregnation. The novel catalyst was analyzed with X‐ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X‐ray spectrometer (EDX). The design of experiment (DoE) method resulted in a total of 20 experimental runs. The significance of 3 reaction parameters, namely catalyst bed height, methanol to waste oil molar ratio, and residence time, and their combined impact on biodiesel yield is investigated. Both the artificial neural network (ANN) based on artificial intelligence (AI) and the Box‐Behnken design (BBD) based on response surface methodology (RSM) were utilized in order to optimize the process conditions and maximize the biodiesel production. A quadratic regression model was developed to predict biodiesel yield, with a correlation coefficient (R) value of 0.9994 for ANN model and a coefficient of determination (R2) value of 0.9986 for BBD model. The maximum amount of biodiesel that can be produced is 98.88 % when catalyst bed height is 7.87 cm, molar ratio of methanol to waste oil is 17.47 : 1, and residence time is 3.12 h. The results of this study indicate that ANN and BBD models can effectively be used to optimize and synthesize the highest %yield of biodiesel in a FBR. [ABSTRACT FROM AUTHOR]

Rechargeable zinc-ion batteries (ZIBs) have grown in popularity due to their low cost and the abundance of resources. However, there has been little research into the development of gel polymer electrolytes (GPEs) for high voltage and capacity ZIBs. The use of agricultural waste as a polymer electrolyte (PE) is gradually increasing in order to support a circular economy. This study focuses on the utilization of cellulose derived from coffee silverskin (CS); coffee silverskin is a by-product generated during coffee roasting. We employ a reasonable approach to create the coffee silverskin cellulose (CSC)/polyacrylamide (PAM) GPE, with the goal of achieving good properties and improved battery performance. An investigation was conducted to determine the effect of CSC content in GPEs on ZIB characteristics. The cellulose derived from CS had a crystallinity index (CrI) of 64.60%. The optimal amount of cellulose added to the acrylamide monomer (AM) for the GPE of ZIB was found to be 2.5 mg (CSC/AM/salt weight ratio of 0.01/6/23). This amount resulted in the highest electrochemical stability and a cycling time of approximately 226 h. Furthermore, the PAM/Cellulose 2.5-based GPE exhibited increased Young's modulus and tensile strength compared to the pure PAM. The electrochemical impedance spectroscopy (EIS) test revealed a diffusion resistance of 27.47 Ω and an ionic conductivity of 9.10 mS/cm at a temperature of 25 °C. Additionally, the use of cellulose in GPEs does not affect the electrochemical window. When the pure PAM-based GPE was compared to the CSC/PAM-based GPE, the biocomposites demonstrated electrochemical stability for a cycle life of over 200 cycles in the ZIB application. [ABSTRACT FROM AUTHOR]

Carbon dioxide (CO2) capture has been identified as a potential technology for reducing the anthropic emissions of greenhouse gases, particularly in post-combustion processes. The development of adsorbents for carbon capture and storage is expanding at a rapid rate. This article presents a novel sustainable synthesis method for the production of chitosan/activated carbon CO2 adsorbents. Chitosan is a biopolymer that is naturally abundant and contains amino groups (–NH2), which are required for the selective adsorption of CO2. Spent coffee grounds have been considered as a potential feedstock for the synthesis of activated coffee grounds through carbonization and chemical activation. The chitosan/activated coffee ground composite microspheres were created using the emulsion cross-linking method with epichlorohydrin. The effects of the amount of chitosan (15, 20, and 25 g), activated coffee ground (10, 20, 30, and 40%w/w), and epichlorohydrin (2, 3, 4, 5, 6, 7 and 8 g) were examined. The CO2 capture potential of the composite beads is superior to that of the neat biopolymer beads. The CO2 adsorbed of synthesized materials at a standard temperature and pressure is improved by increasing the quantity of activated coffee ground and epichlorohydrin. These findings suggest that the novel composite bead has the potential to be applied in CO2 separation applications. [ABSTRACT FROM AUTHOR]

A green catalyst has been derived from a waste material for transesterification of the Jatropha curcas oil feedstock for synthesis of biodiesel in a packed bed reactor (PBR). The razor and surf clam shells were crushed, ground, and calcined at 900°C for 2 h to derive calcium oxide (CaO) as the economic and environmentally friendly catalysts. The heterogeneous catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence, scanning electron microscopy (SEM), and the Brunauer-Emmett-Teller method. The effects of reaction variables such as catalyst bed length (mass of catalyst), residence time (reaction time), reaction temperature, and methanol/oil molar ratio on the % yield of biodiesel were investigated. Long-term repeated operation of PBR was also examined. The optimum conditions were catalyst bed length 250 mm, residence time 1.5 h, reaction temperature 60°C, and methanol/oil molar ratio 15:1 which yielded 98% of the conversion. The CaO catalyst could be used repeatedly for three cycles of methanolysis without activity loss and no activation treatment was required. The fuel properties of fatty acid methyl ester (FAME) were determined. The results indicated that the new green catalysts derived from razor and surf clam shells showed good catalytic performance and had high potential to be used as biodiesel production catalysts in transesterification of J. curcas oil with methanol.

Antibacterial agents produced from plant extracts are seen as a promising application in food packaging. Essential oil extracts, on the other hand, often have drawbacks such as long-term instability, limited bioavailability, and fast burst release. This study's primary goal was to develop poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposite films for use in food packaging, utilizing moringa (M) and guava (G) leaf extracts. The characteristics of polymer films were enhanced by adding a small quantity of GO as a reinforcing filler, and then adding phenolic and flavonoid compounds as antibacterial agents. First, GO and plant extracts were dispersed through the use of ultrasonication. Next, all chemicals were introduced in the PVA matrix with the use of a straightforward and eco-friendly solution casting approach. Water was used as the solvent for this process. As a consequence of these findings, PVA/GO/M3% films demonstrated superior tensile strength (73.63 MPa), % elongation at break (641.94%), and modulus (23.84 MPa) in comparison to neat PVA films. The GO was an effective reinforcing filler, while phenolic and flavonoid compounds were, respectively, crystallization agents. They were distributed randomly in the PVA matrix with no preferred orientation and some agglomeration. Furthermore, the antibacterial activity of the synthetic films loaded with M and G leaf extracts was low when tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). [ABSTRACT FROM AUTHOR]

This research studied the synthesis of green and novel catalysts from waste materials for biodiesel production. An activated carbon (AC) material from palm seed cake (PSC) was soaked with zine chloride (ZnCl2) and treated with sulfonic acid (SO3H). The use of a sulfonated palm seed cake (SO3H-PSC)-derived catalyst for the transesterification/esterification of triglyceride (TG) in waste cooking palm oil (WCPO) was demonstrated. The synthesized SO3H-PSC catalyst was characterized using powder X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), and the Brunauer–Emmet–Teller (BET) method. To study the effects of methanol/oil mole ratio, amount of catalyst, and reaction time, the process of biodiesel production in a microwave reactor was optimized using a Box-Behnken design (BBD) approach with response surface methodology (RSM). As a result, the optimum reaction parameters found were 5.40 wt.% of the SO3H-PSC catalyst, 17.35:1 methanol/WCPO mole ratio, and 8.57 min of reaction time. The synthesized biodiesel from WCPO meets the criteria for standard biodiesel (ASTM D-6751 and EN 14214). The heterogeneous catalyst demonstrates a promising and effective application for the biodiesel process, especially for feedstocks containing high free fatty acid (FFA) content. [ABSTRACT FROM AUTHOR]