Dense medium machine processing method for palm kernel/ shell separation

O.A Ibrahim,C.A Michael,M Mahdi,C Uche,G Sylvester

doi:10.4314/jasem.v21i7.20

Abstract

A machine processing method for the separation of cracked palm kernel from the shells using dense medium is presented. Cracked palm kernel is a mixture of kernels, broken shells, dusts and other impurities. In order to produce quality palm kernel oil, clean palm kernel nuts must be used, therefore the need for the separation of the palm kernel nuts from the shells. Several methods are used in the separation. The handpicking method yields good quality kernels but the method is slow, laborious and unsuitable for large scale productions. Salt solution method is unsuitable because of acidity of concentrated solution of salt used which affects the palm kernel as well as the quality of the oil produced. The clay suspension method is time consuming, laborious and cumbersome. The limitations of the above-stated methods of separation gave rise to the need for alternative methods of separation. A machine processing method using dense medium, a separator, a shell collector and a kernel collector was proposed. A machine was developed which produced kernels that contain 6.5% moisture content, 51% fat, 8.9% protein, 7% free fatty acid and 1.9% ash content. The kernels from the machine separation method were compared with the kernels produced by the other methods. The results revealed that the kernels obtained by hand picking method contains 7% moisture content, 52% fat, 9% protein, 7% free fatty acid and 2% ash content. The ones obtained using salt solution bath method contain 6% moisture content, 45% fat, 8% protein, 4.5% free fatty acid and 1.7% ash content. The ones obtained using conventional clay bath method contain 8% moisture content, 48% fat, 8.5% protein, 5.5% free fatty acid and 1.8% ash content. From the results obtained, the dense medium separation and clay suspension methods provide a better and cleaner means of palm kernel nut and shell separation because of the low moisture content and high fat, protein and ash contents among the methods of separation used. Keywords: Palm Kernel, Shell, Separation, Machine Processing Method, Dense Medium

Highlights

MATERIALS AND METHODDescription of the machine: The dense medium processing machine (Figure 1) comprises of a dense medium tank and a water tank (Figure 2)
Nigeria is one of the world largest exporters of palm kernel products in early sixties, providing about 400,000 metric tons amounting to 65% of the world trade
Palm kernel oil is different from palm oil, which is obtained from the flesh of the palm fruit (Gbasouzor et al, 2012)

Summary

MATERIALS AND METHOD

Description of the machine: The dense medium processing machine (Figure 1) comprises of a dense medium tank and a water tank (Figure 2). Sizing of the tanks: The types of tanks used in this work are two rectangular tanks (for dense medium and water) and three cylindrical (circular) tanks (for the separator, shell collector and palm kernel collector). The pumping head is 2.5m and flow rate 0.63L/s (37.8L/min), based on other design factors such as feed type and operating conditions of the plant, two Pedrollo centrifugal pumps, CPm100 model with the following characteristics volumetric flow rate of up to 60 L/min, power of up to 0.25 kW, dynamic head of up to 15m and pipe size of 1 inch by 1 inch were selected (Pedrollo, 2017). Processing Machine Method: A separating cylinder, kernel and shell collectors, spring balance and a hydrometer were used. Cracked palm kernel-shell mixtures weighing 60kg were poured into the separating tank. The separating tank was tilted to evacuate the floating kernels into the kernel collector where they were washed and transferred for drying

AND DISCUSSION

Findings

Conclusion