Cellulose-based bionanocomposites in energy storage applications-A review.

The growing demand for energy and environmental issues are the main concern for the sustainable development of modern society. Replacing toxic and expensive materials with inexpensive and biodegradable biomaterials is the main challenge for researchers. Nanocomposites are of the utmost consideration for their application in energy storage devices because of their specific electrochemical properties. Cellulose-based bionanocomposites have added a new dimension to this field since these are developed from available renewable biomaterials. Studies on developing electrodes, separators, collectors, and electrolytes for the batteries have been conducted based on these composites rigorously. Electrodes and separators made of these composites for the supercapacitors have also been investigated. Researchers have used a wide range of micro- and nano-structural cellulose along with nanostructured inorganic materials to produce cellulose-based bionanocomposites for energy devices, i.e., supercapacitors and batteries. The presence of cellulosic materials enhances the loading capacity of active materials and uniform porous structure in the electrode matrix. Thus, it has shown improved electrochemical properties. Therefore, these can help to develop biodegradable, lightweight, malleable, and strong energy storage devices. In this review article, the manufacturing process, properties, applications, and possible opportunities of cellulose-based bionanocomposites in energy storage devices have been emphasized. Its challenges and opportunities have also been discussed.

Enhancement of Catalytic Activity on Crude Palm Oil Hydrocracking over SiO2/Zr Assisted with Potassium Hydrogen Phthalate.

In this study, the catalytic activity of bifunctional SiO2/Zr catalysts prepared by template and chelate methods using potassium hydrogen phthalate (KHF) for crude palm oil (CPO) hydrocracking to biofuels was investigated. The parent catalyst was successfully prepared by the sol-gel method, followed by the impregnation of zirconium using ZrOCl2·8H2O as a precursor. The morphological, structural, and textural properties of the catalysts were examined using several techniques, including electron microscopy energy-dispersive X-ray with mapping, transmission electron microscopy, X-ray diffraction, particle size analyzer (PSA), N2 adsorption-desorption, Fourier transform infrared-pyridine, and total and surface acidity analysis using the gravimetric method. The results showed that the physicochemical properties of SiO2/Zr were affected by different preparation methods. The template method assisted by KHF (SiO2/Zr-KHF2 and SiO2-KHF catalysts) provides a porous structure and high catalyst acidity. The catalyst prepared by the chelate method assisted by KHF (SiO2/Zr-KHF1) exhibited excellent Zr dispersion toward the SiO2 surface. The modification remarkably enhanced the catalytic activity of the parent catalyst in the order SiO2/Zr-KHF2 > SiO2/Zr-KHF1 > SiO2/Zr > SiO2-KHF > SiO2, with sufficient CPO conversion. The modified catalysts also suppressed coke formation and resulted in a high liquid yield. The catalyst features of SiO2/Zr-KHF1 promoted high-selectivity biofuel toward biogasoline, whereas SiO2/Zr-KHF2 led to an increase in the selectivity toward biojet. Reusability studies showed that the prepared catalysts were adequately stable over three consecutive runs for CPO conversion. Overall, SiO2/Zr prepared by the template method assisted by KHF was chosen as the most prominent catalyst for CPO hydrocracking.

Facile fabrication of chitosan Schiff bases from giant tiger prawn shells (Penaeus monodon) via solvent-free mechanochemical grafting.

Fabrication of chitosan Schiff bases (ChSB) from giant tiger prawn shells (Penaeus monodon) using an environmentally friendly method has been conducted successfully. Transformation of Prawn Shells (PS) as raw material into chitin then chitosan was executed under ambient temperature. Later, three Ch Schiff bases (ChSB-A, ChSB-S, and ChSB-V) were successfully synthesized for the first time via solvent-free mechanochemical grafting with 2-hydroxy benzaldehyde, 4-methoxy benzaldehyde, and 3-methoxy-4-hydroxy benzaldehyde, respectively. Synthesis was carried out with Shaker Mill-Ultimate Gravity equipped with a Teflon jar with zirconia balls; then the product was characterized. FTIR analysis proved the conversion of free amine to imine groups. The degree of substitution (DS) and crystallinity index (CrI) were determined by elemental analysis and X-ray diffraction. The DS values obtained were about 0.343, 0.795, and 0.055 for ChSB-A, ChSB-S, and ChSB-V, respectively. The CrI of ChSB-A, ChSB-S, and ChSB-V was 53.3, 51.7, and 46.9 %, respectively. The thermal gravimetric analysis showed that the mechanochemical grafting of Ch improves the thermal stability of ChSB. This developed method provides a novel potential technique to convert PS into ChSB products by solvent-free mechanochemical grafting.

Effect of Age and Height on the Chemical Properties of Muli Bamboo (Melocanna baccifera).

Melocanna baccifera is the most common bamboo species which grows naturally and gregariously covering large tracts of land in the forests of Chittagong Hill Tracts of Bangladesh. However, there is limited information about the chemical characterization of its culms for its utilization and processing. This paper aimed to determine the effect of age and height position on the chemical properties of M. baccifera. The highest value of holocellulose content was 74.66% for the top portion of 3-year-old bamboo, while the bottom part of 3-year-old bamboo showed the highest value of lignin (27.83%) and extractive (5.24%) content. For caustic soda (1% NaOH) solubility, the bottom portion of 1-year-old bamboo had shown the maximum value (25.67%), and it was the lowest (19.10%) for the top portion of 3-year-old bamboo. Ageing had a significant (p < 0.05) effect on all chemical properties, while the height position had a significant effect on the holocellulose and lignin content and water solubility. The chemical properties of M. baccifera can enable its proper utilization in the downstream process.

Hydrocracking of crude palm oil to a biofuel using zirconium nitride and zirconium phosphide-modified bentonite.

In this study, bentonite modified by zirconium nitride (ZrN) and zirconium phosphide (ZrP) catalysts was studied in the hydrocracking of crude palm oil to biofuels. The study demonstrated that bentonite was propitiously modified by ZrN and ZrP, as assessed by XRD, FTIR spectroscopy, and SEM-EDX analysis. The acidity of the bentonite catalyst was remarkably enhanced by ZrN and ZrP, and it showed an increased intensity in the Lewis acid and Brønsted acid sites, as presented by pyridine FTIR. In the hydrocracking application, the highest conversion was achieved by bentonite-ZrN at 8 mEq g-1 catalyst loading of 87.93%, whereas bentonite-ZrP at 10 mEq g-1 showed 86.04% conversion, which suggested that there was a strong positive correlation between the catalyst acidity and the conversion under a particular condition. The biofuel distribution fraction showed that both the catalysts produced a high bio-kerosene fraction, followed by bio-gasoline and oil fuel fractions. The reusability study revealed that both the catalysts had sufficient conversion stability of CPO through the hydrocracking reaction up to four consecutive runs with a low decrease in the catalyst activity. Overall, bentonite-ZrN dominantly favored the hydrocracking of CPO than bentonite-ZrP.

Pyrolysis of cajuput (Melaleuca leucadendron) twigs and rice (Oryza sativa) husks to produce liquid smoke-containing fine chemicals for antibacterial agent application.

Pyrolysis of cajuput (Melaleuca leucadendron) twigs and rice (Oryza sativa) husks to produce liquid smoke and antibacterial activities of the liquid smoke fractions were investigated. The liquid smoke was produced by pyrolysis at 500 °C for 8 h and contained fine chemicals, such as acetic acid, carbonyl, cyclic ketones, and phenolic compounds with pH 2.1-2.9. The liquid smoke was separated by vacuum evaporation under vacuum conditions at low temperatures (40 °C, 50 °C, and 60 °C) to recover three fractions. The composition of each fraction influenced its antibacterial activities. Antibacterial activities of the liquid smoke fractions were tested against Gram-positive bacteria (Listeria monocytogenes, Bacillus subtilis, and Staphylococcus aureus) and Gram-negative bacteria (Salmonella typhimurium, Pseudomonas aeruginosa, and Escherichia coli). Whole fractions of the liquid smoke inhibited the six pathogenic bacteria, with the inhibition zone larger or smaller than the positive control. Among the liquid smoke fractions, the liquid recovered at 60 °C for the cajuput twigs and rice husks demonstrated a stronger inhibitory effect on bacterial growth than the other fractions.