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The synthesis, characterization, optimization and oxidation stability improvement of biodiesel from the seed oil of sesame indicum using a novel nano-heterogeneous bio-catalyst derived from the Chrysophyllum albidium seed coat (CASC) is reported. The heterogeneous catalyst was produced by calcination and activation at 400 °C, 600 °C and 800 °C using acetic acid. The catalyst was characterized using scanning electron monograph (SEM), Fourier transform infrared (FTIR), and x-ray diffraction (XRD). The seed oil was extracted using mechanical press milling and the biodiesel produced were characterized using AOAC 2019 edition and ASTM D-6151, Fourier transform infrared (FTIR) and gas chromatography (GC) methods. The results indicated that calcined Chrysophyllum albidum seed coat contains nano-particles and alkaline elements (75 % graphite). The calcination process improved the size reduction and structural arrangement of the particles. The 600 °C calcination temperature had the highest biodiesel yield of 88 % at 3.0 wt % catalyst concentration, 12:1 M ratio of alcohol to oil and 500 rpm. The reusability of catalyst indicated 71.50 % after fifth (5th) cycle. After 28 days storage duration in the presence of the natural, renewable and eco-friendly antioxidant (1 % turmeric), the oxidation instability of the produced biodiesel was reduced by 50 %. The quality of the biodiesel indicates agreement with standards and literature as well as high potential for effective application in diesel engine.

In this work, the feasibility of nitric acid (HNO3) and hydrogen peroxide (H2O2) binary solution as a leachant for alumina leaching from Owhe kaolinite was examined. The leaching was carried out by batch process. Least squares method was deployed to examine the experimental results. The results show that the percentage of alumina dissolved recorded an increase with increase in the concentration of H2O2 and temperature and recorded a reduction with increase in solid/liquid (S/L) ratio and particle size. Chemical reaction was established as the rate-determining step. About 89% alumina was leached on the average with activation energy (Ea) of 4.406 kJ/mol while the overall rate constant was 1.067 s−1. A binary solution of HNO3 and H2O2 showed viability for Owhe kaolinite leaching. Analysis of residue remaining after leaching by energy dispersive spectrometer (EDS) showed the major elements found in the residues as silicon, aluminum, and titanium. [ABSTRACT FROM AUTHOR]

Silica-coated limestone (SCL) microcapsule was synthesized and successfully introduced into acrylic resin to produce fire-retardant coatings. SCL microcapsules were prepared by encapsulating limestone granules with silica nanoparticles using epoxy resin as a binder. The morphology and the chemical composition of the SCL microcapsules were confirmed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), respectively. The performance of SCL microcapsules on mechanical, flame retardant and thermal stability of the coatings was thoroughly investigated using FTIR, SEM, thermogravimetric analysis (TG), smoke density test, adhesion pull-off test, pendulum damping test and cone calorimeter test. The results shows that while the adhesion strength, pendulum hardness and limiting oxygen index (LOI) increased remarkably, the values of flame spread ratings (FSR), specific optical density (ODs), heat release rate (HRR), total heat release rate(THRR), smoke production rate (SPR) and total smoke production rate (SPR) decreased significantly with the introduction of SCL microcapsules. The TGA results confirm that incorporation of SCL microcapsules increases the thermal stability and boosts formation of large char layers. [ABSTRACT FROM AUTHOR]

Purpose: The impact of potassium permanganate (KMnO4) treatment on the tensile strength of an alkali-treated pineapple leaf fiber (PALF) reinforced with tapioca-based bio resin (cassava starch) was studied. Design/methodology/approach: The PALF was exposed to sodium hydroxide (NaOH) treatment in varying concentrations of 2.0, 3.7, 4.5 and 5.5g prior to the fiber treatment with KMnO4. The treated and untreated PALFs were reinforced with tapioca-based bio resin. Subsequently, they were subjected to Fourier transform infrared (FTIR) and tensile test analysis. Findings: The FTIR analysis of untreated PALF revealed the presence of O-H stretch, N-H stretch, C=O stretch, C=O stretch and H-C-H bond. The tensile test result confirmed the highest tensile strength of 35N from fiber that was reinforced with 32.5g of cassava starch and treated with 1.1g of KMnO4. In comparison, the lowest tensile strength of 15N was recorded for fiber reinforced with 32.5g of cassava starch without KMnO4 treatment. Originality/value: Based on the results, it could be deduced that despite the enhancement of bioresin (cassava starch) towards strength-impacting on the fibers, KMnO4 treatment on PALF is very vital for improved tensile strength of the fiber when compared to untreated fibers. Hence, KMnO4 treatment on alkali-treated natural fibers preceding reinforcement is imperative for bio-based fibers. [ABSTRACT FROM AUTHOR]