Effect of Amount of Brine Added on Oil Recovery
Fig. 3 indicates the impact of added brine on OR. It was only 37% without the addition of brine (aqueous NaCl solution). It gradually increased as the quantity of added brine raised from 0.00 to 1.80 mL. However, it decreased when the amount of brine added was further increased to 2.00 mL. It should be noted the highest OR obtained by the addition of 1.80 mL brine (93.82%) was lower than that obtained by the addition of only water (97.73%). This experiment again proved that salt did not improve the OR.
Effect of Temperature and Time of Agitation on Oil Recovery
The effect of temperature during agitation on OR is shown in Fig. 3. The OR was maximum (97.73%) when the agitation was undertaken at room temperature (24 ℃). It gradually decreased as the agitation temperature was increased from 24 to 60 ℃. Therefore, an increase in agitation temperature adversely affected OR.
The effect of time of agitation on OR is shown in Fig. 3. The OR was 65% without stirring. The increase in the OR was very significant when the agitation time was raised from 0 to 30 minutes. As the agitation time continued to increase, the OR tended to be stable.
Agitation is necessary for facilitating the contact of water with hydrophilic groups of small solid particles when mixing with the slurry of pecan kernel. This step results in the aggregation of all compounds which are hydrophilic so that all oils are discharged and the observation of free oils or a continuous oil phase is achieved.