Synthesis of Palm Oil Based Trimethylolpropane Esters with Improved Pour Points

Abstract

Palm oil based trimethylolpropane (TMP) esters are potential biodegradable base stocks for environmentally friendly lubricants. To improve the low-temperature properties of palm oil based TMP esters, which are well below the requirements set by the lubricants' manufacturers, the high oleic content palm oil based TMP ester with a pour point between −10 and −32 °C was synthesized. The synthesis of palm oil polyol esters was performed by transesterification of fractionated palm oil methyl esters with TMP using sodium methoxide as a catalyst. Nearly complete conversion to palm TMP triesters (98% w/w) was obtained. The palm oil methyl esters were fractionated at 150−180 °C and 0.1 mbar prior to the synthesis to reduce the saturated fatty acid content. The fractionation and reaction took place using the same experimental setup. The effects of composition on pour points, viscosity, and viscosity index of the high oleic content palm oil based TMP esters were also evaluated. The concentration of C16:0 methyl ester in the starting material should be below 10% w/w to ensure that the pour points of high oleic content palm oil based TMP esters are below −30 °C. In addition, the reaction conversion to triester must also be maintained above 90% w/w to produce TMP esters with excellent pour points. Operating temperature had a negligible effect on the reaction yield so long as the temperature was kept above 120 °C. There were small variations in the viscosities and viscosity index values of high oleic content palm oil based TMP, in the region of 50 cSt and 199, respectively.

A Review of Bio-lubricant Production from Vegetable Oils Using Esterification Transesterification Process

“…The existence of bio-lubricant products showed by the composition pentaerythrityol tetraoleate (PETO) and trimethylolpropane ester (TMPE) which is the result of a reaction between PEE and POME [24]. The optimal reaction conditions were obtained, namely at a temperature of 158°C, the catalyst concentration of 1.19% and a molar ratio of 4.5:1 with a reaction time of 60 minutes.…”

Palm Oil Derived Trimethylolpropane Triesters Synthetic Lubricants and Usage in Industrial Metalworking Fluid

“…The fatty acid profiles of palm methyl esters PME , the fractionated oleic palm methyl esters OPME from Yunus 19 work as well as the commercial oleic acids COA-1 and COA-2 were also listed in Table 1 for comparison purposes. Commercial TMPTOs are usually synthesized via chemical esterification reaction using TMP and oleic acid, hence commercial COAs were considered for the comparison purposes.…”

“…However, poly-unsaturated fatty acids at the same time may make the oils oxidatively and hydrolytically unstable 21,22 . PME typically contain high saturates content of approximately 45 w/w and this attributes to a higher pour point TMP triesters with pour point 0 19 . TMP triesters produced from PME is therefore only suitable in the tropical climate countries with no…”

“…Esterification synthesis method involves TMP and fatty acids using acid catalysts. One of the common acids used is p-toluene sulfonic acid 14 19 had also attempted to synthesis TMP triesters with high oleic content from fractionated high oleic methyl esters and achieved a pour point of 30 while maintaining the viscosity as well as other properties. High oleic methyl ester is available commercially and commercialized as winter grade biodiesel Carotino company, Malaysia .…”

Effects of additives on oxidation characteristics of palm oil‐based trimethylolpropane ester in hydraulics applications

“…The mixture was heated in an oil bath under reduced pressure until the TMP melted at around 60 7C. The mixture was gradually heated to the operating temperature and refluxed under reduced pressure, 0.1 mbar, for 2 h as described earlier [9]. The oil was refined before it was used as the base oil for hydraulic fluid applications.…”