Effect of Moisture Content, Nut Size and Hot-Oil Roasting Time on the Whole Kernel “Out-Turn” of Cashew Nuts (Anacardium occidentale) During Shelling

ABSTRACTThe effect of moisture content (MC), nut size and roasting time (RT) on the whole kernel out-turn (WKO) of cashew nuts during shelling was investigated in this study. Cashew nuts were graded into three sizes: small (18 – 22mm), medium (23 – 25mm) and large nuts (26 – 35mm). About 3kg of nuts from each grade was conditioned with water at 25°C to five moisture levels of 8.34, 11.80, 12.57, 15.40 and 16.84% (wb). The nuts were subjected to roasting in hot cashew nut shell liquid at a temperature range between 180 and 190°C for 0.75, 1.00, 1.25, and 1.50min. The nuts were then shelled using a hand-operated shelling machine. The results showed that pre-shelling treatment of cashew nuts enhanced WKO. The single effect of MC, roasting time (RT) or nut size distribution is not enough for estimating WKO; it is rather by an interaction of these parameters. The average WKO of raw nuts was characteristically below 50% at all combinations of MC and RT. Pre-treatment by roasting was found to improve WKO considerably. The highest values were 96.96, 99.63 and 100% for large, medium and small-sized nuts at MC*RT of 16.84%*1min, 16.84%*1min and 15.4%*1.5min respectively. As RT and MC increased, WKO increased within the experimental range

Effect of Pre-Treatments on Mechanical Oil Expression from Dika Kernels

ABSTRACTThe effect of pre-treatments on mechanical oil expression from dika kernels was investigated in this study. The parameters considered were particle sizes (fine and coarse), moisture content (4, 6, and 8%), heating temperature (30, 40, and 50°C), heating time (15, 35 and 45min) and applied pressure (5, 10 and 15MPa). The results showed that the oil point pressure of dika kernels reduced with increase in heating temperature and time and moisture content. The highest oil point pressure for coarse particles was recorded at 2.11MPa; whereas oil point pressure for fine particles was below 1MPa. The lowest pressure at which oil began to flow was 0.41MPa (at 50°C and 8.3% MC) while the highest was 0.65MPa (at 30°C and 4.2% MC). The optimal oil point pressure ranged from 0.55 to 0.65MPa for fine particles and 1.51 to 2.11MPa for coarse particles. The least oil yield was at 4% moisture content at 5Mpa for coarse particles; whereas the highest yield was obtained at 4% moisture content at 15MPa for fine particles. For coarse particles, resistance to oil flow decreased significantly with increase in moisture content, heating temperature and heating time. The optimal oil expression occurred at pressure range of 0.55 to 0.65MPa for fine particles and 1.51 to 2.11MPa for coarse particles. Dika kernel has a high oil content, which makes it valuable for oil production. An understanding of the response of oil yield to various pre-treatments will provide valuable information for the optimization of dika oil expression

Potentials for Generating Alternative Fuels from Empty Palm Fruit Bunches by Pyrolysis

The threat that the disposal of empty palm fruit bunches constitute to communities in oil palm processing areas in Nigeria coupled with the current global focus on alternative energy is the trigger for this work. An existing pyrolytic reactor consisting of a reactor unit, condensate receiver, copper pipe connectors and gas receiver was modified and adapted for converting empty palm fruit bunches to alternative fuels. The average char yield was 44.9%, and the percentage of feedstock converted into pyrogas and tar oil was 55.1%. The char yield decreased gradually as temperature was increased from 300-700°C. Char yield was highest (39.78%) when the temperature was 300°C and the lowest char yield was 25.05% at 700°C The calorific values of char ranged between 21.12 and 23.76 MJ/kg. Apart from the potential of generating energy from pyrolysed EFB, it abates the disposal problem that EFB constitutes in the oil palm industry

Analysis of Cost Estimation and Wind Energy Evaluation Using Wind Energy Conversion Systems(WECS)for Electricity Generation in Six Selected High Altitude Locations in Nigeria

Two commercial wind turbines namely AN Bonus 300 kW/33 and AN Bonus 1 MW/54 were technically assessed for electricity generation in six selected high altitude sites spreading across the North-West and North-East geopolitical regions of Nigeria by computing their capacity factors, annual power and energy outputs. The economic evaluation of using the two wind energy conversion systems (medium and large) for electric power generation in the selected locations were also estimated using the present value cost method. The results showed that capacity factors of the two turbines in the selected sites ranged between 4.6 and 43%. Average minimum cost per kW h was obtained in Kano as $0.0222/kW h with AN Bonus 1 MW while the highest average cost is$0.2074/kW h with AN Bonus 300 kW in Kaduna. The highest cost in each of the location was obtained with the medium WECs (AN Bonus 300 kW). In addition, Kano and Katsina were also found to be very economical for any of the adopted wind turbine models. Gusau and Kaduna, at cost of unit energy of about $0.30/kW h were found to be more profitable for non-connected electrical and mechanical applications (water pumping, battery charging) than diesel generator

Pyrolytic conversion of spent palm fruit bunches into bio-fuels

The threat which the disposal of spent palm fruit bunches constitutes to communities in oil palm processing communities in Nigeria coupled with the current global interest in alternative energy are the motivation for this work. An existing design of pyrolytic reactor consisting of a reactor unit, condensate receiver, copper pipe connectors and gas receiver was modified and adapted for converting spent palm fruit bunches into bio-fuels. The average char yield was 44.9 %, and the percentage of feedstock converted into pyro-gas and tar oil was 55.1 %. The char yield decreased gradually as temperature was increased from 300-700°C. Char yield was highest (39.78 %) when the temperature was 300°C and the lowest char yield was 25.05 % at 700 °C and the calorific values of char ranged between 21.12 and 23.76 MJkg-1. This work presents the potential of generating energy from pyrolysed Spent Palm Fruit Bunches (SPFB), it abates the disposal problem that SPFB constitutes in the oil palm industr

Effect of Pre-Treatments on Mechanical Oil Expression from Dika Kernels

The effect of pre-treatments on mechanical oil expression from dika kernels was investigated in this study. The parameters considered were particle sizes (fine and coarse), moisture content (4, 6, and 8%), heating temperature (30, 40, and 50oC), heating time (15, 35 and 45 min) and applied pressure (5, 10 and 15 MPa). The results showed that the oil point pressure of dika kernels reduced with increase in heating temperature and time and moisture content. The highest oil point pressure for coarse particles was recorded at 2.11 MPa; whereas oil point pressure for fine particles was below 1 MPa. The lowest pressure at which oil began to flow was 0.41 MPa (at 50oC and 8.3% MC) while the highest was 0.65 MPa (at 30oC and 4.2% MC). The optimal oil point pressure ranged from 0.55 to 0.65 MPa for fine particles and 1.51 to 2.11 MPa for coarse particles. The least oil yield was at 4% moisture content at 5 Mpa for coarse particles; whereas the highest yield was obtained at 4% moisture content at 15 MPa for fine particles. For coarse particles, resistance to oil flow decreased significantly with increase in moisture content, heating temperature and heating time. The optimal oil expression occurred at pressure range of 0.55 to 0.65 MPa for fine particles and 1.51 to 2.11 MPa for coarse particles. Dika kernel has a high oil content, which makes it valuable for oil production. An understanding of the response of oil yield to various pre-treatments will provide valuable information for the optimization of dika oil expression.Keywords: Dika kernel, oil expression, pressure, moisture content, temperature, particle size

Analytical Approach for Predicting Biogas Generation in a Municipal Solid Waste Anaerobic Digester

There is an increasing worldwide interest in the effective utilisation of municipal solid wastes as an avenue of reducing its high cost of clearing. Municipal solid wastes are usefully converted into a medium grade fuel (biogas) to reduce its nuisance value to the environment. In this paper, the potential of vegetable (putriscible) component of municipal solid wastes was examined in terms of biogas production. The vegetable component of the waste was used as substrate in a batch-fed 200 dm3 capacity anaerobic digester, which was consecutively loaded with a 10-20 kg ranged weight of vegetable. The total solid (TS) of substrate was 8-10% over a retention period of 40 days. The temperature of the substrate during bio-digestion was maintained within 29ºC and 33ºC. The average biogas yield varied from 5.15 dm3/kgTS to 5.83 dm3/kgTS. From the digestion experiments, a regression equation, called the municipal solid wastes energy value model, was derived. This model estimates the biogas production from municipal solid wastes. For the predictive model formulation, a relationship between retention time and the daily/total biogas yield was explored. The polynomial function significantly represents the models formulated for the different quantity of substrate loaded. This strongly suggests that the polynomial series is best suited to predict the relationship between retention time and the quantity of substrate loaded for the experiment. This tool is useful in optimising biogas production from energy materials, and requires further validation and refinement. Hopefully, this study advances this increasingly growing area of municipal solid wastes research