Synthesis and characterization of ethylene glycol ester from spent bleaching earth oil and ethylene glycol as hydraulic lubricants

Abstract

Solid waste of Spent Bleaching Earth (SBE) containing a small amount of oil is generated in the processing Crude Palm Oil (CPO) into cooking oil. Recovery of the oil from SBE from extraction process can produce SBEO (spent bleaching oil), a low-grade oil which has dark color, contain significant amount of FFA (free fatty acid) and solidified at ambient temperature. In this research, this SBEO is utilized as biolubricant after treating through 2 step of processes. The first step is the conversion of SBEO into methyl ester by decolorization, FFA reduction, and transesterification processes. The second step is conversion of methyl ester into ethylene glycol ester. Transesterification of the SBE into methyl ester by methanol at ratio 1:6, give yield of 99.74. While second step transesterification of methyl ester into ethylene glycol is conducted by ethylene glycol. Temperature of 170°C has the best result of yield (93%). Physical characteristic of the ethylene glycol product give density at 40°C of 0.91 gr/cm3 and viscosity (at 40°C) of 9,75 cSt, flash point of 252°C, pour point of-7°C. This Physical characteristic meet the standard SNI 7069.9-2016 for hydraulic lubricant