Effect Of Time On Crystallization Rate PDF

EFFECT OF TIME ON THE RATE OF CRYSTALIZATION AIM: To study the effect of time on the rate of crystallization. REQUIREMENTS:  Beakers  Slide  Cover slip  Microscope PROCEDURE:  Refined bleached and deodorized palm oil are placed in a beaker which was initially h...

EFFECT OF TIME ON THE RATE OF CRYSTALIZATION AIM: To study the effect of time on the rate of crystallization. REQUIREMENTS:  Beakers  Slide  Cover slip  Microscope PROCEDURE:  Refined bleached and deodorized palm oil are placed in a beaker which was initially heated in a thermally controlled water bath for 30 minutes at 70ºC to totally melt the oil.  The temperature was then reduced to 30ºC within one hour followed by reducing to crystallization temperature of 14 or 22ºC within 30 minutes.  Once the oil reached the desired temperature (14 or 22ºC), it was allowed to crystallize until 90 minutes where the analyses were made at 5,15,30,60 and 90 minutes to obtain the morphology of the crystals.  The beaker content was constantly stirred at 90 rpm throughout the process using a stirring motor attached with two blades paddle propeller  Samples of slurries were withdrawn at 5,15,30,60 and 90 minutes of crystallization and placed onto a slide which was then covered with a cover slip.  Photograph of the crystals were taken at the magnification of 200x.  The lengths of four longest dimensions of each crystal were recorded and an average of at least six crystals was measured during each observation.  Observation table: Time (min) Crystal Size (µm) 5 15 30 60 90 Report: Rate of crystallization of palm oil at the end of 90 minutes is = µm.