An assessment of the potential availability of selected residues from maize, cassava, millet, plantain, groundnuts, sorghum, oil palm, palm kernel, and cowpeas for possible conversion to renewable energy in Nigeria has been made. It is estimated that nearly 58 million tonnes of these residues were potentially available in the year 2004 with energy potential of about 20.8 million tonnes oil equivalents. The residue availability for 2010 is projected to be about 80 million tonnes. These residues, when converted to energetically usable forms, can substitute or complement the fossil energy sources in Nigeria by more than 80%.

Potential Availability of Energetically Usable Crop Residues in Nigeria

Analysis of energy usage in the production of three selected cassava-based foods in Nigeria

Energetic analysis of fruit juice processing operations in Nigeria

The Energy Commission of Nigeria’s long term (2016-2025) plan on the nation’s energy
requirements is completely non-fossil. This is borne out of the global depletion of the nonrenewable
energy sources, its attendant negative environmental impact and the intent to utilize
the hitherto neglected abundant renewable resources in Nigeria. Locally produced Palm kernel
oil (PKO) is currently being investigated as an alternative source of diesel fuel amongst other
efforts at executing the country’s renewable energy master plan. Transesterification of PKO with
ethanol was carried out using potassium hydroxide (KOH) catalyst on a laboratory scale and
standard fuel characterization (ASTM fuel tests) was carried out on the resulting biodiesel. This
work further considers the effect of varying mixing time on PKO biodiesel yield. Three
replicated transesterification experimental runs were carried out for each of the mixing duration
30, 45, 60, 75, 90, 105 and 120min under identical typical transesterification reaction conditions
of 100g PKO, 60OC temperature, 1.0% KOH concentration and 20% ethanol (wt% PKO).
Results showed PKO biodiesel fuel properties (viscosity, specific gravity, cloud point, pour point
and flash point) to be within international biodiesel standard specifications while average PKO
biodiesel yield of 87.4, 90.1, 92.5, 94.2, 96.0, 96.0 and 96.0% was obtained for the respective
mixing duration. Optimal yield of the PKO biodiesel, within the constraint of the typical
transesterification process parameters used, was found to be 90min.

Optimal transesterification duration for biodiesel production from Nigerian palm kernel oil.

Estimating energy requirement in cashew (Anacardium occidentale L.) nut processing operations

Direct energy utilization in nine palm‐kernel oil (PKO) mills located in Southwestern Nigeria was analyzed. The mills were stratified into small, medium and large‐scale categories, based on their modes of operations and production capacities. Evaluation of energy usage was carried out in the seven readily defined unit operations namely: palm‐nut drying, palm‐nut cracking, palm‐kernel roasting, palm‐kernel crushing, PKO expression, PKO sifting and PKO bottling/pumping. PKO extraction rates in the three mill categories were evaluated. The average PKO extraction rate for small, medium and large mills were 48.45 percent, 42.68 percent and 36.24 percent, respectively. The total energy expenditure in small, medium and large‐scale PKO mills were 350.89MJ/tonne, 230.70MJ/tonne and 181.74MJ/tonne, respectively. This suggests that the unit energy requirement for PKO output decreases as mill capacity increases. The four most highly energy‐intensive operations identified were palm‐nut cracking, palm‐kernel roasting, palm‐kernel crushing and PKO expression, altogether accounting for 95.29, 92.14 and 93.65 percent of total energy used in small, medium and large‐scale mills, respectively.

Energy requirements for palm‐kernel oil processing operations

A study was conducted in three southwestern states of Nigeria to evaluate the energy
requirements and man-machine relationships in bread-baking operations. The study, which
lasted over one year, involved the use of three fuel sources namely, firewood, electricity and
cooking gas during bread baking operations. Questionnaire and physical measurements were
employed for data collection from fifty bakeries randomly selected within the study area. The
data points include the environmental and body temperatures, anthropometrical data, bio data,
injury data, metabolic and production measurements.The results of the study revealed that
bread-baking with wood as energy source required the highest energy (6.15 kJ/min) compared
with 3.37 kJ/min and 1.52 kJ/min obtained with gas and electricity as sources of energy
respectively. The cost of energy per kg of baked bread was N7.58 ($ 0.059) with cooking gas
as the energy source followed by N6.05 ($ 0.047) for electricity and N5.05 ($ 0.04) for wood
in that order. The average baking rate using firewood, gas and electricity as energy sources
were 11.92 kg/h, 17.97 kg/h and 20.58 kg/h respectively. Analysis of metabolic data showed
moderate increase in the subjects’ body temperatures, blood pressures and heart rates after
bread baking operations. Epidemiological study showed that all age groups sustained bakery
injuries while using various implements. More than 80% of the victims were workers below
34 years of age. The study suggests that bread-baking operations could be categorized as a
light grade work and that the use of electricity as energy source is the most appropriate in
terms of bread baking rate and unit energy requirement.

Ergonomic Evaluation and Energy Requirements of Bread-baking Operations in South Western Nigeria

Purpose – In Nigeria, local fabricators of agro‐processing equipment have designed and manufactured various improvised versions of imported bread‐baking machines without due ergonomic considerations. Also, most of the processes of bread baking in Nigeria largely involve manual materials handling, which continues to represent a major loss source in the work place. The manual operations besides being uncomfortable are characterized by low output and unhygienic products. A study was therefore conducted in three southwestern states of Nigeria with the purpose of evaluating the energy requirements and man‐machine relationships in bread‐baking operations.Design/methodology/approach – The study, which lasted over one year, involved the use of three fuel sources namely, firewood, electricity and cooking gas during bread baking operations. Questionnaire and physical measurements were employed for data collection from 50 bakeries randomly selected within the study area. The data points include the environmental and...

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Ergonomic evaluation and energy requirements of bread‐baking operations in south western Nigeria

Purpose – In Nigeria, the mango fruits consumption rate is high during its peak period and this has always resulted in environmental sanitation problem because the mango seeds are thrown to the surroundings immediately the fruits are eaten. Finding more useful application of the kernel would be a way to reduce the environmental pollution. Mechanical decortication of the leathery mango stone remains the only viable option that can support any prospected commercial uses of the mango kernel.Design/methodology/approach – The decorticator consists of a hopper, a decorticating chamber, spiked shaft, screen shaker and discharge spout. The machine performance was evaluated in terms of decorticating efficiency, mechanical damage and sieve loss.Findings – Results of the evaluation show that the optimum performance of the decorticator was at a speed of 900rpm, feed rate of 250kg/h and power requirement of 2.50kW.Originality/value – Mango stones are useful as substitute for maize in finishing broiler diets. The kerne...

S.O. Jekayinfa

Papers

Energy requirements for palm‐kernel oil processing operations

Ergonomic Evaluation and Energy Requirements of Bread-baking Operations in South Western Nigeria

Ergonomic evaluation and energy requirements of bread‐baking operations in south western Nigeria

Performance evaluation of a mango stone decorticator