Effect of Reaction Parameters on CO2 Absorption from Biogas Using CaO Sorbent Prepared from Waste Chicken Eggshell.

This study provides an efficient and straightforward approach to eliminate carbon dioxide (CO2) by absorption using a calcium oxide (CaO) sorbent derived from chicken eggshells. The sorbent concentration, stirring speed, and contact time were varied. The optimal condition for CO2 removal was a 10% calcium hydroxide (Ca(OH)2) suspension at 600 rpm with 20 min interaction. This optimum condition conferred the ever-highest absorption (98.71%) of CO2 through Ca(OH)2 suspensions from eggshell-derived CaO. X-ray diffraction was used to identify crystallographic phases and optimum conditions revealed calcium carbonate (CaCO3) formation with the highest intensity, Fourier transform infrared spectroscopy revealed peaks for the carbonate (CO32-) group, field emission scanning electron microscopy was used to investigate the morphological and structural properties of the sorbent before and after CO2 absorption, and thermogravimetric analysis was performed to understand the reaction mechanism. According to the kinetic analysis, the sorbent can be fully decomposed with a minimum activation energy (Ea) of 89.09 kJ/mol.

Triglyceride Conversion of Waste Frying Oil up to 98.46% Using Low Concentration K+/CaO Catalysts Derived from Eggshells.

In this study, biodiesel, also known as fatty acid methyl ester (FAME), was synthesized from multi-stage frying waste soybean oil using chicken eggshell-derived CaO and potassium-impregnated K+-CaO heterogeneous catalysts. Potassium-impregnated catalysts (1.25% K+-CaO, 2.5% K+-CaO, and 5% K+-CaO) were developed by treating the calcined waste eggshell powder with KOH in different wt % ratios. The catalysts were characterized using FTIR, XRD, FESEM, EDS, BET, and particle size analysis techniques. Box-Behnken design-based optimization was exploited to optimize the reaction parameters. A maximum yield of 98.46%, calculated via 1H NMR, was achieved following a 5% K+ doping, 12:1 methanol to oil molar ratio, 3% catalyst amount, 180 min reaction time, and 65 °C reaction temperature. The catalyst (5% K+-CaO) responsible for maximum biodiesel production was found to be highly reusable, with a 30.42% conversion decrease in activity after eight cycles of reuse. Gas chromatography was used to determine the composition of FAME produced from different cycles of waste soybean oil. Physicochemical parameters of the synthesized biodiesel were found to be compatible with EN and ASTM standards. This study has shown that the waste eggshell-derived heterogeneous catalysts have significant catalytic activity at relatively low K+ doping and catalyst loading leading to high biodiesel conversion.

Biocompatible microcrystalline cellulose particles from cotton wool and magnetization via a simple in situ co-precipitation method.

This investigation describes the preparation of magnetically doped degradable microcrystalline cellulose (MCC) nanocomposite particles with application potential in biotechnology, solid support for biomolecule/water purification, oil recovery from water and beyond. MCC was first extracted from cotton wool, the most abundant biocompatible polymer, by sulfuric acid hydrolysis and the effect of acid strength was examined. The size of the elongated fiber structure was reduced with increasing acid strength. MCC particles extracted by treatment with 70% sulfuric acid were used to prepare magnetic MCC nanocomposite particles. The nanocomposite particles named as MCC/Fe3O4 were prepared via in situ co-precipitation of Fe+3/Fe+2 from their alkaline solution. The precipitated Fe3O4 nanoparticles are expected to be bonded with MCC particles via hydrogen bonding. The nanocomposite dispersion was colloidally stable and the particles responded when external magnetic field was applied. It was possible to control the magnetic property by regulating the content of iron oxide.