Energy requirements for palm‐kernel oil processing operations

Abstract

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.

Development of equations for estimating energy requirements in palm-kernel oil processing operations

“…Variation in the specific energy across and within PKO mills are not unconnected with operational factors such as age of the equipment installed, current cost of energy, type of fuel available and extent to which available plant capacity is used. Jekayinfa and Bamgboye (2004), Megbowon andAdewunmi (2002) and, Miller (1986) have made similar observations in studies involving milk processing, two agro-allied industries and cashew nut processing, respectively. Table 4 presents the regression equations relating energy consumption to palm-kernel/nut input for each unit operation in the three mill categories.…”

Potential Availability of Energetically Usable Crop Residues in Nigeria

“…These conditions are similar to those in the continent of Africa. The peels represent about 2-3% of the weight of the tuber and this would yield about 1 tonne of peels per hectare at 50% moisture content (Jekayinfa and Bamgboye, 2004). The heating value of cassava peels and stalk have been estimated to be 13.38 and 10.61 MJ/kg, respectively (Suwannakhanthi, 2004).…”

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

“…This approach is similar to that used in previous studies by Ezeike (1981) and Jekayinfa and Bamgboye (2003, 2004, 2007. Using energy accounting symbols presented by Singh (1978) with slight modifications, energy and mass flow diagrams (Figs.…”

“…They submitted that a tea garden required an estimated 18,408 MJ/ha of human energy in the first year. Other similar works reported in literature relating to evaluation of energy efficiency in processing industries include cashew-nut processing in Nigeria (Jekayinfa & Bamgboye, 2003, 2006; palm-kernel oil processing in Nigeria (Jekayinfa & Bamgboye, 2004, 2007 rice production in Bangladesh (Islam, Rahman, Saker, Ahduzzaman, & Baqui, 2001) sugar-beet production in Morocco (Mrini, Senhaji, & Pimentel, 2002) and, energy and labour use in Italian agriculture (Pellizzi, 1992). This study was undertaken to investigate the energy use pattern in the selected cassava processing mills in southwestern Nigeria and to develop predictive models that could estimate and optimize the energy demand of each unit operation for different selected cassava products.…”

“…1. The estimation of thermal energy (obtained from the use of fuel), electrical energy (obtained from electricity use from the national grid) and manual energy (from human labour) was done as follows (Jekayinfa & Bamgboye, 2004, 2006, 2007.…”