Synthesis and characterization of metal sulfates loaded Palm Empty Fruit Bunch (PEFB) for biodiesel production

Biodiesel has been globally accepted as a green substitute for diesel fuel. However, the insecurity of food raised with the application of edible sources in biodiesel production has caused much debate. The feasible alternative technique is the use of inedible and low-grade sources such as palm fatty acid distillate (PFAD). In this work, the production of biodiesel (FAME) from PFAD using solid acid catalysts (SACs) derived from palm empty fruit bunch (PEFB) is investigated. The SACs were synthesized through impregnation of different metal sulfate precursors, i.e. ferrous sulfate heptahydrate (FeSO4 .7H2 O), copper sulfate pentahydrate (CuSO4 .5H2 O), and magnesium sulfate heptahydrate (MgSO4 .7H2 O) over PEFB. SEM-EDX observations found that impregnation and then calcination resulted in attachment of sulfur (S) and improved surface porosity. FT-IR analysis showed that there were distinct interactions between metal sulfates and PEFB. XRD characterization showed that the prepared catalysts have a crystalline structure. Besides, the catalytic activity of the SACs was closely associated with their acid densities measured by the titration method. Fe-PEFB catalyst showed the highest acid density (2.44 mmol/g) among the catalysts studied. To study the effect of process parameters on FFA conversion (%), optimization of methanol: PFAD molar ratio, catalyst dosage, reaction temperature, and reaction time was conducted. Maximum FFA conversion of 89.1% was obtained over Fe-PEFB while Cu-PEFB and Mg-PEFB achieved an FFA conversion of 63 and 56.5%, respectively, under the optimum reaction conditions. Thus, the present study offers a sustainable and environmentally benign method for biodiesel production

Synthesis and characterization of metal sulfates loaded palm empty fruit bunch (PEFB) for biodiesel production

Biodiesel has been globally accepted as a green substitute for diesel fuel. However, the insecurity of food raised with the application of edible sources in biodiesel production has caused much debate. The feasible alternative technique is the use of inedible and low-grade sources such as palm fatty acid distillate (PFAD). In this work, the production of biodiesel (FAME) from PFAD using solid acid catalysts (SACs) derived from palm empty fruit bunch (PEFB) is investigated. The SACs were synthesized through impregnation of different metal sulfate precursors, i.e. ferrous sulfate heptahydrate (FeSO4.7H2O), copper sulfate pentahydrate (CuSO4.5H2O), and magnesium sulfate heptahydrate (MgSO4.7H2O) over PEFB. SEM-EDX observations found that impregnation and then calcination resulted in attachment of sulfur (S) and improved surface porosity. FT-IR analysis showed that there were distinct interactions between metal sulfates and PEFB. XRD characterization showed that the prepared catalysts have a crystalline structure. Besides, the catalytic activity of the SACs was closely associated with their acid densities measured by the titration method. Fe-PEFB catalyst showed the highest acid density (2.44 mmol/g) among the catalysts studied. To study the effect of process parameters on FFA conversion (%), optimization of methanol: PFAD molar ratio, catalyst dosage, reaction temperature, and reaction time was conducted. Maximum FFA conversion of 89.1% was obtained over Fe-PEFB while Cu-PEFB and Mg-PEFB achieved an FFA conversion of 63 and 56.5%, respectively, under the optimum reaction conditions. Thus, the present study offers a sustainable and environmentally benign method for biodiesel production

Investigation of the pH effect in hydrothermal growth of zinc oxide nanostructures

This study focuses on the influence of the pH value of hydrothermal solution on the morphology and the transmission spectrum of zinc oxide (ZnO) nanostructures using field-emission scanning electron microscope (FE-SEM) and ultraviolet-visible (UV-Vis) spectroscopy, respectively. The ZnO nanostructures were grown on glass substrates at 90oC for 5 hours. The pH and the concentration of the starting solutions were varied from 2.03 to 12.02 and 6 mM to 100 mM respectively. Various ZnO structures of neuron-like, flowerlike, and urchin-like morphologies were obtained at alkaline pH (~8.00 to ~9.00) while for pH solution lower than ~8.00, rod-like nanostructures were obtained. Solution of pH value 11.50 shows that growth of nanostructures was suppressed due to the high susceptibility to erosion in both acidic and alkaline solutions. By changing the concentrations of the solution, the density and size were also varied. The increase in concentration lead to the increase of nanostructure density and the diameter of ZnO nanorods. The trend shows that the concentration solution from lower (C 100mM) resulted ZnO nanostructures such as nanorods to thick film due to overgrowth and coalescence of the nanostructures with more available precursors

An Optimization of Nanostructure Aluminum on Porous Silicon at Different Aluminum Thickness

The growth of aluminum nanostructure was conducted on porous silicon substrate by depositing a layer of aluminum via thermal evaporation method. The deposition process of the aluminum nanostructure was under the annealing temperature at 350°C for 1 hour. The weight of aluminum was varied for each sample in order to obtain different thickness of aluminum deposited on the sample. The weight of aluminum used in this experiment were 12mg ,18mg ,50mg and 74mg with the corresponding aluminum thickness deposited of 112nm, 163nm, 205nm and 332nm. Characterization on the morphology of the sample are conducted by using Atomic force microscopy (AFM), Raman spectroscopy and IV measurements. Based on the result obtained, the optimum weight of aluminum was 50mg of aluminum since it is provide the higher conductivity value on the sample

Surface morphology of In0.5Ga0.5 quantum dots grown using Stranski-Krastanov growth mode

In this research an atomic force microscopy (AFM) study on self-assembled In0.5Ga0.5As/GaAs quantum dots (QDs) was performed. Surface morphology of self-assembled In0.5Ga0.5As QDs changes with different growth time. Increasing growth time increased the dots size and decreased the dots density. In addiditon, self-assembled In0.5Ga0.5As QDs was grown on In0.1Ga0.9As underlying layer with different after-growth AsH3 flow time during cooling-down. The underlying layer caused lattice strain relaxation in the QDs on the surface. Increasing the period of AsH3 flow during cooling-down reduced the diameter of the dots and increased the density. The migration of groups III species in the growth of In0.5Ga0.5As/GaAs system was influenced by AsH3 flow during cooling-down period. This was due to the increase in surface population of active arsenic species. Underlying layer and the period of AsH3 flow during cooling-down are the two key factors in the fabrication of small and dense In0.5Ga0.5As QDs

Formation of self-assembled Ge islands on Si (100) using magnetron sputtering and subsequent rapid thermal annealing

Formation of Ge island after an ex-situ thermal annealing of Ge-rich film on Si (100) were investigated. Ge film was deposited using radio-frequency magnetron sputtering with the substrate being at room temperature. The film was then thermal annealed at an elevated temperature using a rapid thermal processor (RTP) in nitrogen ambient. The structural changes of the annealed film were studied using atomic force microscopy (AFM). Following annealing at temperature above 500oC, island assembling from Ge film were observed. The size of these islands were about 80-180nm wide 4-30nm in height. Density of the islands increases as annealing temperature increases up to 700oC. The surface morphology of the samples after annealing varies with various thickness of the Ge layer deposited on Si (100). The formation of the island was explained to form via the same mechanism as Stranski-Krastanov mode though it is not epitaxially grown. The high temperature annealing causes the adatoms to migrate and forms to islands as to minimize the surface energy

TiO2 Based Dye-Sensitized Solar Cell Prepare by Using Spray Pyrolysis Deposition (SPD)

Titanium dioxide (TiO2) thin films have been produced on the Fluorine-doped Tin Oxide (FTO) glass substrates by using the techniques of spray pyrolysis deposition and annealed at different of temperature. The film was annealed within 3 hours for each thin film. The different temperature that used for annealed is 300℃, 400℃, and 500℃. In this study is shown that, when the temperature is increased, the efficiency of the thin film also increases. On the surface, morphology and electrical properties of TiO2 DSSC thin film were examined by using FESEM and electrical measurement was calculated by I-V analysis. FESEM procedure characterizes, is for surface morphology and grain size. Raman spectroscopy analysis used to provide a fingerprint by which molecules can be identified and information about molecular vibrations that can be used for sample identification and quantitation. on electrical properties, the measurement of resistance and resistivity used common methods 2 point-prob and the efficiency of DSSC was measured by Solar Simulator. At the end, the objectives accomplish to produce TiO2 thin film with high efficiency to be applied in the DSSC

Misconceptions on the understanding of flying objects in fluids

The concepts of floating, flying, and sinking object have been studied since junior high school. However, we still often find students' misconceptions regarding the concept, especially of flying objects, even at the university level. This work aims to propose a clarification of the concept of a flying object in the fluid to be correctly described the condition for the flying object. We used eggs, water, and salt solutions to demonstrate sinking, rising, and floating objects in the fluids. The results showed that when the density of the object is the same as the density of the fluid, the position of the object is still at the bottom of the fluid since it was not flying in the middle of the depth of the fluid. But the object does not touch the bottom of the container so that the object's height is zero. This is because the object has not had a driving force (Fd = 0) that pushes the object upward towards the surface of the fluid to float. When the density of the fluid slightly exceeds the density of the object, the object immediately moves upward to the fluid surface - floating phenomenon is started. The greater the difference between the density of the fluid and the density of the object, the faster the object moves towards the surface. The object cannot stay at any position between the bottom and the surface of the fluid. A stable position is reached when the object reaches the surface of the fluid to float. This work is expected to increase students' understanding of flying objects in fluids