Joni, ImeldaYusnimarYenie Elvi2013-03-132013-03-132013-03-13rio andikahttp://repository.unri.ac.id:80/handle/123456789/2551In the palm oil refining industry, bleaching process CPO was performed using bleaching agent. This process aims is to change the color of CPO from reddish brown to pale yellow and clearness. Bleaching agents can be made from the bentonite. Bentonite is a clay mineral with the chemical composition of approximately 80% consists of the mineral monmorillonite (Na.Ca) 0.33 (Al.Mg)12Si4O10(OH)2nH2O (Rouquenol, 1999). Bleaching ability of bentonite can be improved by chemical and physical activation in order to increase the surface area and modify the structure of bentonite. Chemical activation process is done using 5N HCl and physical activation process carried out by heating in the furnace for 6 hours under temperature of 400oC. This research focused specifically the effect variations studied of particle size (-40 +60 mesh, -60 +80 mesh and -80 +100 mesh) and adsorption time (1 hour, 2 hours, 3 hours, 4 hours, and 5 hours) to improve the adsorption power of bentonite. The results of this research can be statement that the particle size variation and adsorption time of adsorption power are affected on adsorption power bentonite which were tested by using methylene blue. The adsorption power has been increasing as smaller as the particle size (-40 +60 mesh, -60 +80 mesh and -80 +100 mesh). The adsorption time were increasing (1 hour, 2 hours, 3 hours, 4 hours, and 5 hours) influenced the adsorption power of bentonite to methylen blue is increase as well. Equilibrium adsorption process between bentonite to methylen blue was achieved in 4 hours. The maximum adsorption power of bentonite activated physically and chemically was found under condition particle size of -80 +100 mesh bentonite adsorption at 4 hours. Bentonite activated physically better than chemically. The analysis results of CPO bleaching process using bentonite activated physically is yellow with a scale value of 40 at Lovibond Tintometer, FFA content of 0.09% and the number of peroxide is 1.24 meqH2O2/kg oil.otheradsorption powerbleachingbentonitechemical activatedphysically activatedstudent Paper Post Degree