Fractionation - Process Quality Control

 Process and Product Quality Control

            In palm oil fractionation, olein fraction is the desired product and it is important to increase the olein yield, at the same time maintaining the oil quality. Important parameters for palm olein characterization are IV, cloud point and cold test. Normally, palm oil fractionation can give a yield up to 80 %. On the other hand, the desired product in PKO fractionation is the stearin fraction which can be used as CBS. Hence, the objective in PKO fractionation is to maximize the stearin yield. Important parameters for stearin are SFC (especially 30^oc), SMP and IV. A good quality stearin will have a steep SFC profile.

alm Oil Fractionation

High final crystallization temperature will produce larger and better crystal which is easier to filter. However, this will give low stearin yield and olein with low IV. At the same time, the stearin IV will be low and olein yield is high. On the other hand, low final crystallization temperature will produce lot of smaller crystal which is weaker. In this case, the olein produced is high IV with low yield. The stearin will be high IV and high yield.

Agitation rate is another important parameter in a crystallization process. This is because crystallization is an exothermic process and oil is a rather poor heat conductor. If heat produced during crystallization process can not be removed effectively, it will melt some of the crystal causing uneven crystal formation. This will lead to difficult filtration. Hence, agitation is required to give intimate mixing of the oil for good heat transfer. On the other hand, high agitation rate tent to break the crystal causing secondary crystallization. Second crystallization will lead to uneven crystal formation. As a result, high agitation rate is used in cooling step and lower agitation rate is used in the crystal formation state.

Palm Kernel Oil Fractionation

In PKO fractionation, the important parameters that affect the product quality and yield are final slurries solid fats content, static crystallizer temperature and holding time. High final slurries solid fat content indicate that there are a lot of nucleus initiated and this will give a smaller crystal in cake formation steps. If the cake formed in static crystallizer is too soft, there are 2 possible reasons, namely temperature too high or holding time too short in static crystallizer. Soft cake will lead to low stearin yield and low stearin and kolein IV. On the other hand, hard cake will give higher stearin yield with high stearin and olein IV.