Biodiesel Generation from Palm Kernel Biomass via an In-situ Transesterification Approach

This study investigated an in-situ transesterification of palm kernel biomass at variable reaction times (4 h, 5 h and 6 h) and catalyst loading (2 wt%, 3 wt.% and 5 wt.%). The biodiesel yields were observed to vary with these parameters. GC-MS analysis showed high fatty acid methyl esters (FAMEs) contents for all the prepared biodiesel samples (C-18:1, C-14:0, C-16:0, and C-18:0). 2 wt.% catalyst loading and 4 h reaction time were observed to be the best reaction conditions from the experimented parameters that gave the best biodiesel yield at 300 rpm mixing intensity. The in-situ method recorded a higher degree of oil extraction and efficient conversion of oil to biodiesel (93.93%) compared to the conventional transesterification method which gave 89.45%. The kinematic viscosity, acid value and iodine value of 3.96 mm2/s, 0.56 mg KOH g–1 and 120 g 100 g–1 were found to be within the limits of ASTM D6751-09 and EN14214 standards. These results confirm that efficient production of biodiesel from palm kernel biomass could be possible through an in-situ acidic transesterification process.  Keywords: Biodiesel, fatty acid methyl ester, palm kernel biomass, transesterificatio

Synthesis of Polydispersed P(St-MMA-AA) Microspheres and Fabrication of Colloidal Crystals with Non-Compact Morphology

Great attention has been given to the synthesis of monodispersed and uniform colloidal polymer particles with controllable particle sizes. However, investigations on the preparation, characterization and fabrication of polydisperse polymeric particles are very few. Polydisperse polymers are also needed to meet the new demands of the modern markets due to the ease of their synthesis. This study, therefore, synthesized polydispersed poly(styrene-methyl-methacrylate acrylic-acid) (P(St-MMA-AA)) via emulsion polymerization synthetic approach under unstable reaction conditions. The synthesized P(St-MMA-AA) microparticles were characterized using Fourier transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), a thermo-gravimetric analyzer (TGA) and scanning electron microscope (SEM). The DLS results revealed a highly polydispersed P(St-MMA-AA) microparticles with an average particle diameter of 803.4 nm. SEM, TEM (transmission electron microscopy) and AFM (atomic force microscopy) analyses showed that the particles were spherical and polydispersed. The unequal diameters and non-compact nature of the fabricated colloidal crystals may have affected its possible uses in some specific applications such as decorative coatings, biomedical and sensing applications. However, other materials can be incorporated into the polydispersed prepared P(St-MMA-AA) colloidal microspheres to improve their properties and possible applications. Keywords: Emulsion polymerization; Polydispersed; Polymer; P(St-MMA-AA)

Stabilizing Capability of Gum arabic on the Synthesis of Poly(Styrene-Methylmethacrylate-Acrylic Acid) Latex for the Generation of Colloidal Crystal Films

This article describes the generation and characterization of colloidal crystals from particles of gum arabic (GA) and sodium dodecylbenzene sulfate (SDBS) emulsified poly(styrene methylmethacrylate-acrylic acid) (P(St-MMA-AA) latex. The colloidal latex was synthesized using GA and SDBS as the emulsifying agents and then used to generate colloidal crystal films via the vertical deposition technique. Dynamic light scattering analysis placed the average particle diameter, polydispersity and Zeta potential at about 122 nm, 0.014 and –36.20 mV for the as-synthesized GA emulsified terpolymer latex and 213 nm, 0.006, –35.60 mV for the SDBS emulsified terpolymer latex, respectively. Thermo-gravimetric analysis and differential scanning calorimetry showed comparable thermal stability for both prepared terpolymer samples. Microscopic analysis showed that the latex particles possess a core-shell morphology which readily assembles into a well ordered hexagonal arrangement of spherical particles with manifold layers. This study, therefore, shows comparable properties of terpolymer prepared using gum arabic as emulsifier with terpolymer synthesized using SDBS which is a conventional emulsifier. Keywords: Gum Arabic; sodium dodecylbenzene sulphate; colloidal crystal films; morphology; emulsifie

PM2.5-bound polycyclic aromatic hydrocarbons (PAHs): quantification and source prediction studies in the ambient air of automobile workshop using the molecular diagnostic ratio

Abstract The presence of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere has been linked to health concerns, including cancer. Automobile workshops are significant contributors to PAH emissions due to their operations. Hence, this investigation aimed to identify and quantify the sources of PM2.5-bound PAHs in the ambient air of automobile workshops in Benin City, Nigeria, using molecular diagnostic ratios. PM2.5 samples were collected from 60 automobiles over 1 year, during the rainy (April to November) and dry (December to March) seasons of 2019. Sample collection utilized a low-volume air sampler with quartz filter paper, and extraction was performed using a 1:1 mixture of acetone and dichloromethane. The analysis involved an HP Agilent Technology 6890 Gas Chromatography (GC) system with a flame ionization detector. The annual average concentrations of PM2.5-bound PAHs in Benin City were 269.87 ± 249.32 ng/m3 (dry season) and 216.30 ± 204.89 ng/m3 (wet season). Molecular diagnostic ratios, such as Fl/(Fl + Py), An/(An + Phe), BaP/(BaP + Chry), BbF/BkF, InP/(InP + BghiP), and BaA/(BaA + Chr), aided in identifying PAH sources. Gasoline combustion, diesel combustion, traffic emissions, and emissions from automobile panel welders were found to be the primary sources of PAHs near vehicle workshops. These findings provide crucial insights for developing effective strategies to reduce emissions and protect public health in the air surrounding automobile workshops in Benin City