SYNTHESIS OF FATTY ACID ETHYL ESTER FROM CHICKEN FAT USING ZnO/SiO2 HETEROGENEOUS CATALYST

The synthesis of fatty acid ethyl ester from chicken fat waste using ZnO/SiO2 heterogeneous catalyst was carried out using two-step procedures of acid pretreatment by esterification and transesterification of the pretreated oil. The first step reduces the high free fatty acid in the oil to an acceptable level for transesterification using concentrated sulphuric acid at a temperature of 60 oC during 1 h of reaction time. The second step was transesterification of the preheated oil using silica promoted zinc oxide as heterogeneous catalyst. A three level, four factorial box behnken design (BBD) of response surface methodology was used whereby the biodiesel yield obtained in the range of 56−88%and a second order quadratic polynomial regression model that established the relationship between biodiesel yield and the process variables was developed. The quality of the produced biodiesel was determined by investigating its physicochemical properties which results are obtained for specific gravity at 15oC to be 0.889 g/cm3, Flash point was 175oC, Cloud Point was -3oC, Pour point was -8oC, Cetane number was 57.72 and Kinematic Viscosity at 40oC was 7.95mm2/s. The results obtained are consistent and in line with ASTM standard for biodiesel; hence, chicken fat as non-edible oil can be a good renewable feedstock for biodiesel production for a sustainable green environment.  http://dx.doi.org/10.4314/njt.v35i1.1

Transesterification of Crude Jatropha Curcaslinnaeus Oil Catalyzed by Waste Marble Derived Solid Catalyst

Transesterification of crude jatropha oil with methanol was investigated using a heterogeneous catalyst derived from waste marble. The barium enhanced waste marble catalyst was prepared via precipitation/impregnation methods and showed high performance to methyl ester conversion when calcined at 830 oC for 4 h. The high activity of the solid oxide catalyst resulted from the basic-sites generated from the synergetic composite formed with high dispersion of the active species as indicated from characterization data with Brunauer-Emmett-Teller (BET) surface area, 56.01 m2/g, average pore size, 123.63Å, and pore volume, 0.17 cm3/g. The methyl ester content of 70.36% was achieved over the catalyst within 4 h under the optimal transesterification conditions of methanol/oil molar ratio of 15:1, catalyst amount of 5 wt % and reaction temperature of 65 oC. The research provides insight into application of waste marble enhanced with barium as potential catalyst in the heterogeneously catalyzed transesterification of crude jatropha oil in mild conditions.http://dx.doi.org/10.4314/njt.v34i1.1

Melon husk-based activated carbon for treatment of industrial wastewater

The adsorption of organic contaminants from industrial effluent using melon husk activated carbon has been investigated. Melon husk was carbonized at 450oC for 20 minutes and activated with sulphuric acid to produce granular activated carbon (AC). The fixed carbon increased with increase in concentration of activating agent. The effect of concentration of activating agent, adsorbent dose and contact time on adsorption of organic contaminants from Coca Cola wastewater was examined at room temperature. The AC prepared with 1.0 M activating agent proved to be the most effective in contaminants removal when dosage and contact time were varied individually. The optimum COD removal of 98.76% was achieved while 88.48% COD removal was attained in 5 hours. The concentration of contaminants, measured as COD reduced to a value within the allowable discharge limit after treatment. The experimental batch equilibrium data was correlated by Langmuir and Freundlich adsorption isotherms. The adsorption data fitted better into the Freundlich isotherm. The adsorption kinetic data follows pseudo-second order kinetics and the rate constants obtained with pseudo-second order kinetics are in close agreement with the experimental values.Keywords: Melon husk activated carbon; Wastewater; COD; Adsorption isotherms, Kinetic studies

Simultaneous Transesterification of Baobab Seed (Adansonia digitata) Oil Using Heterogeneous Zn/SiO2 Supported Catalyst

Using heterogeneous Zn/SiO2 supported catalyst, simultaneous transesterification of Baobab seed (Adansonia digitata) was investigated. Parameters such as temperature, catalyst loading, water dilution, acid concentration and methanol seed ratio were investigated. The results show that Baobab seed oil was successfully converted to methyl ester with the highest yield of 50.9 % at the temperature of 70 oC, catalyst loading of 1 wt. %, water dilution of 50 mL, at 2 h reaction time, methanol seed ratio of 15:1 and 1 M of acid concentration. The properties of the Baobab seed methyl ester gave the following: specific gravity, 0.87, pour point, -6 oC, cloud point, 2 oC, flash point, 150 oC, Cetane number , 49, which is comparable with the ASTM D6751 standards for methyl esters.Keywords: Heterogeneous catalyst, Simultaneous transesterification, Baobab seed, Methyl este

Modeling and Simulation of Energy Recovery from a Photovoltaic Solar cell

Photovoltaic (PV) solar cell which converts solar energy directly into electrical energy is one of the feasible alternative sources to fossil fuel. This study aims at predicting the energy recovery from a typical photovoltaic solar cell, BP 3 series 235 W solar panel, by developing a reliable mathematical model of the solar panel which could represent the real systems. The model equation was solved using the ‘solve block’ tool in MathCAD 14 software and validated by physical data obtained from literature. Using the model developed the effects of temperature and solar irradiance on performance of PV solar panel was investigated using nominal conditions of 298 K and 1000 W/m2 as basis. Temperature was varied between 273, 298, 323, 348 and 373 K at constant irradiance of 1000 W/m2. Solar irradiance was also varied using 200, 400, 600, 800 and 1000 W/m2 while maintaining temperature at 298 K. The energy recovery from the PV model was evaluated using the fill factor concept. From the analysis of results, there is some agreement between the simulation results and the reported experimental performance of the PV solar panel. The performance of the PV system increased with increase in temperature and solar irradiance. In purview of values of solar irradiation (200 – 1000 W/m2) and temperature (273 - 373 K) that were studied, the energy recovery was maximum at 79.98% which agrees with values of between 75 and 85% obtained in practical solar cells.Keywords: Photovoltaic, Mathematical model, Energy recovery, Simulatio