| dc.description.abstract | Ester biolubricant has been synthesized from waste cooking oil (WCO) and pentaerythritol by using catalyst and solvent Deep Eutectic Solvents (DESs) and homogenizer. WCO refinery was by addition of 0.05% (v/v) H3PO4 and 2% (m/v) bleaching earth. The refined WCO was hydrolyzed by saponified it using ethanolic NaOH 12% followed by hydrolysis the WCO with H2SO4 25% to separate fatty acid and glycerol. Optimization of ester biolubricant synthesis has been done by using Box-Behnken Design (BBD) with fatty acid and pentaerythritol mol ratio 4:1, DESs percentage based on fatty acid weight (45%, 60%, and 75%), reaction time (30 mins, 45 mins, and 60 mins), and homogenizer stirrer velocity (3,000 rpm; 5,000 rpm; and 7,000 rpm). AV and FFA were determined by alkalimetry titration, %H2O by KF Titrino Plus instrument, composition of WCO fatty acid by GC, the change of functional group from WCO fatty acid to ester biolubricant by FT-IR Spectrophotometer, molecular weight determination of ester biolubricant by LC-MS/MS, viscosity by Viscometer Ostwald, viscosity index by SVM 3001 Viscometer, and flash point by Pensky-Martens Flash Point. Average value of AV, FFA, and %H2O were 22.49, 11.30%, and 0.08%. The WCO fatty acid average AV was 152.27. Total composition saturated fatty acid was 42.514%, unsaturated fatty acid was 55.912%, and unknown was 1.572%. The range conversion percentage of 15 ester biolubricant variation based on Box-Behnken Design were 31.90%-62.42% and the ester biolubricant conversion percentage for optimum parameter (DESs 55%, reaction time 60 mins, and stirrer velocity 3000 rpm) was 63.17%. Ester biolubricant from optimized parameter was characterized by FT-IR Spectrophotometer. The indicators for ester existence were the stretching vibration of carbonyl (C=O) absorption at 1715 cm-1 and absorption at 1170 cm-1 which originate from C-O-C ester stretching vibration. The molecular weights determination of esters was depicted as monoester pentaerythritol oleic (C18:1), monoester pentaerythritol palmitic (C16), and diester pentaerythritol caprylic-palmitic (C8-C16) by LC-MS/MS. Furthermore, the viscosity and viscosity index of ester biolubricant were 5.009 cP and 98.57, while the flash point was 91.7oC. | en_US |
