The analysis on the oil properties of fatty acid esters

• Main Authors: Yun-Han Chang, 張宇涵
• Other Authors: Yi-Hung Chen
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/5maqus

碩士 === 國立臺北科技大學 === 化學工程研究所 === 104 === The desire to replace petroleum‐based lubricants with alternatives that are environmentally friendly and made from sustainable sources has encouraged the development of biolubricants based on vegetable oils. To be a suitable lubricant, it should has low pour points and appropriate viscosities. In this study, we used the gas chromatograph to analyze the compositions of fatty acid esters and the ester contents. In the meanwhile, we also analyzed the properties of the oils. At the last, we compared the specifications of the commercial products with our products to get more appropriate ester oils. We used four kinds of natural fats: oleic acid (OA), palm fatty acid distillate (PFAD), palm sludge oil (PSO) and soybean acid oil (SAO) to be our raw materials for the preparations of 2-ethyl-1-hexanol (2-EH) and propylene glycol (PG) esters. The esters were esterified from free fatty acids of OA, PFAD, PSO and SAO with 2-EH or PG to produce the base oil for biolubricant production. The analysis of the final product (ethyl hexyl esters) was performed by using the gas chromatography, which exhibited that the esters contents of ethyl hexyl oleate, ethyl hexyl PFAD esters, ethyl hexyl PSO esters, and ethyl hexyl SAO esters were 99.82%, 94.4%, 82.84%, and 91.07%, respectively. The other ingredients, ethyl hexyl esters and a little FFAs, were currently still unable to perform the qualitative analysis. The gas chromatography analysis of ethyl hexyl ester revealed two major esters peaks, i.e. ethyl hexyl palmitate and ethylhexyl oleate. The physical properties of ethyl hexyl esters synthesized were as follows: The viscosity at 40 oC was in the range of 5.98–9.51 mm2/s. The pour point was smaller than -25 to -9 oC. And the viscosity index was very high. It’s higher than 180. All the properties of ethyl hexyl ester were similar to the related commercial products. We also analyzed propylene glycol ester by using gas chromatography. The peaks of the monoesters and the diesters revealed two major ranges at 16–26 min and 26–41 min in the chromatograms, respectively. According to our results, the reflected diesters contents of the propylene glycol oleate, propylene glycol PSO esters and propylene glycol SAO esters were 86.86%, 89.18% and 95.97%, respectively. The other ingredients mainly were monoesters and a little FFAs. The physical properties of the products were as follows: The viscosity at 40 oC was in the range of 17.55–22.47 mm2/s. The pour point was in the range of -18–20 oC. And the viscosity index was 197–254. Because the pour points of propylene glycol PSO esters and propylene glycol SAO esters couldn&;#39;t be less than 0 oC, they were unsuitable to be base oils.