Trimethylolpropane Ester Research Articles

Immobilized lipase-catalyzed transesterification for synthesis of biolubricant from palm oil methyl ester and trimethylolpropane.

The present study reports the effects of three commercial immobilized lipases namely Novozyme 435 from Candida antarctica lipase B (CALB), Lipozyme TL IM from Thermomyces lanuginosus and Lipozyme RM IM from Rhizomucor miehei on the production of trimethylolpropane (TMP) ester from high oleic palm methyl ester (HO-PME) and TMP. The TMP ester is a promising base oil for biolubricants that are easily biodegradable and non-toxic to humans and the environment. Enzymatic catalysts are insensitive to free fatty acid (FFA) content, hence able to mitigate the side reactions and consequently reduce product separation cost. The potential of these enzymes to produce TMP ester in a solvent-free medium was screened at various reaction time (8, 23, 30 and 48h), operating pressure (0.1, 0.3 and 1.0mbar) and enzyme dosage (1, 3, 5 and 10% w/w). The reaction was conducted at a constant temperature of 70°C and a molar ratio of 3.9:1 (HO-PME: TMP). Novozyme 435 produced the highest yield of TMP ester of 95.68 ± 3.60% under the following conditions: 23h reaction time, 0.1mbar operating pressure and 5% w/w of enzyme dosage. The key lubrication properties of the produced TMP ester are viscosity index (208 ± 2), pour point (- 30 ± - 2°C), cloud point (- 15 ± - 2°C), onset thermal degradation temperature (427.8°C), and oxidation stability, RPVOT (42 ± 4min). The properties of the TMP ester produced from the enzymatic transesterification are comparable to other vegetable oil-based biolubricants produced by chemical transesterification.

Identification and source attribution of organic compounds in ultrafine particles near Frankfurt International Airport

Abstract. Analysing the composition of ambient ultrafine particles (UFPs) is a challenging task due to the low mass and chemical complexity of small particles, yet it is a prerequisite for the identification of particle sources and the assessment of potential health risks. Here, we show the molecular characterization of UFPs, based on cascade impactor (Nano-MOUDI) samples that were collected at an air quality monitoring station near one of Europe's largest airports, in Frankfurt, Germany. At this station, particle-size-distribution measurements show an enhanced number concentration of particles smaller than 50 nm during airport operating hours. We sampled the lower UFP fraction (0.010–0.018, 0.018–0.032, 0.032–0.056 µm) when the air masses arrived from the airport. We developed an optimized filter extraction procedure using ultra-high-performance liquid chromatography (UHPLC) for compound separation and a heated electrospray ionization (HESI) source with an Orbitrap high-resolution mass spectrometer (HRMS) as a detector for organic compounds. A non-target screening detected ∼200 organic compounds in the UFP fraction with sample-to-blank ratios larger than 5. We identified the largest signals as homologous series of pentaerythritol esters (PEEs) and trimethylolpropane esters (TMPEs), which are base stocks of aircraft lubrication oils. We unambiguously attribute the majority of detected compounds to jet engine lubrication oils by matching retention times, high-resolution and accurate mass measurements, and comparing tandem mass spectrometry (MS2) fragmentation patterns between both ambient samples and commercially available jet oils. For each UFP stage, we created molecular fingerprints to visualize the complex chemical composition of the organic fraction and their average carbon oxidation state. These graphs underline the presence of the homologous series of PEEs and TMPEs and the appearance of jet oil additives (e.g. tricresyl phosphate, TCP). Targeted screening of TCP confirmed the absence of the harmful tri-ortho isomer, while we identified a thermal transformation product of TMPE-based lubrication oil (trimethylolpropane phosphate, TMP-P). Even though a quantitative determination of the identified compounds is limited, the presented method enables the qualitative detection of molecular markers for jet engine lubricants in UFPs and thus strongly improves the source apportionment of UFPs near airports.

Investigation on Synthesis of Trimethylolpropane (TMP) Ester from Non-edible Oil

Trimethylolpropane (TMP) ester is an eco-friendly lubricant that fully biodegradable and known as bio lubricant. In this study, TMP ester was produced from waste cooking oil and rubber seed oil through a two-step synthesis approach. The reaction is two stages transesterifications, in which the waste cooking oil and the rubber seed oil were first transesterified with methanol to produce methyl ester, followed by transesterification with TMP using para-Toluenesulfonic acid (p-TSA) as catalyst. Various effects of operating conditions were observed, such as reaction time, temperature and molar ratio of reactants. The TMP ester formation was determined based on the quantity of reactant conversion. The synthesized TMP ester was compared and characterized according to their properties. The results showed that the TMP ester from waste cooking oil (WCO) has shown better conversion compare to TMP ester from rubber seed oil (RSO), within a similar operating condition. The highest TMP ester conversion from WCO is 71%, at temperature of 150 ºC with molar ratio of FAME to TMP of 3:1 and catalyst amount of 2% (wt/wt). In addition, these polyol based esters from WCO and RSO exhibit appropriate basic properties for viscosity when compare with requirement standard of lubricant ISO VG46. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

An acceleration of microwave-assisted transesterification of palm oil-based methyl ester into trimethylolpropane ester

Microwave-assisted synthesis is known to accelerate the transesterification process and address the issues associated with the conventional thermal process, such as the processing time and the energy input requirement. Herein, the effect of microwave irradiation on the transesterification of palm oil methyl ester (PME) with trimethylolpropane (TMP) was evaluated. The reaction system was investigated through five process parameters, which were reaction temperature, catalyst, time, molar ratio of TMP to PME and vacuum pressure. The yield of TMP triester at 66.9 wt.% and undesirable fatty soap at 17.4% were obtained at 130 °C, 10 mbar, sodium methoxide solution at 0.6 wt.%, 10 min reaction time and molar ratio of TMP to PME at 1:4. The transesterification of palm oil-based methyl ester to trimethylolpropane ester was 3.1 folds faster in the presence of microwave irradiation. The total energy requirement was markedly reduced as compared to the conventional heating method. The findings indicate that microwave-assisted transesterification could probably be an answer to the quest for a cheaper biodegradable biolubricant.

Biolubricant base stock with improved low temperature performance: Ester complex production using housefly (Musca domestica L.) larval lipid

Lipid generated from housefly ( Musca domestica L.) larvae fed by municipal waste is a renewable lipid resource, however, the low unsaturated degree prevents it from producing trimethylolpropane fatty acid triester as lubricant, due to its poor low-temperature performance. A new fatty acid esters complex consisting of trimethylolpropane fatty acid triester and 2-ethylhexyl fatty acid ester was produced from housefly larval lipid. Separated from molecular distillation, the acylglycerols were first trans-esterified into fatty acid methyl ester and then further trans-esterified with trimethylolpropane into trimethylolpropane esters. The purified trimethylolpropane fatty acid triester is with purity of 98.4% and further blended with 30 wt% 2-ethylhexyl fatty acid ester derived from housefly larval free fatty acid. The pour point was substantially lowered from −3 °C to −12 °C while the lubricity performance is within standard of ISO VG 32, with minor improvement of water separability compared with pure trimethylolpropane fatty acid triester. By blending two type bio-lubricants with different advantages on viscosity and pour point, the ester complex with favorable properties was produced using saturated non-food lipid source rather than unsaturated virginal vegetable oil. This study also offers a cleaner and energy-efficient approach for high value-added product production for non-food lipid industry. • Mixture of esters was produced from housefly larval lipid through bioconversion. • Free fatty acid fraction is used for producing pour point depressant. • Pour point of TFATE is lowered to −12 °C by adding 30 wt% 2-EH ester. • Viscosity of the esters mixture is within ISO VG 32 lubricant standard. • The proposed method has high energy efficiency and product value.

Environmentally friendly processes from coffee wastes to trimethylolpropane esters to be considered biolubricants

ABSTRACT In this study, an eco-friendly renewable biodegradable alternative to petroleum-based oil lubricants was produced using espresso coffee wastes. Waste coffee oil used as raw material was extracted from Espresso coffee wastes by Soxhlet and conventional solvent extraction. Free fatty acids (FFA) were obtained by hydrolysis of the obtained waste oil using Lipozyme TL IM (Thermomyces lanuginosus). The byproduct, glycerol, was also separated from the reaction medium using a separatory funnel. The obtained FFA was used as a raw material in the production of TMP esters. Polyol esters of fatty acids were synthesized as a result of the esterification reaction between FFA and polyol alcohol (trimethylolpropane (TMP)) using Novozyme 435 (Candida antarctica). The amount of FFA in the medium and the FFA conversion was determined by titration with NaOH solution according to ASTM D 5555–95 standard and the FFA composition of espresso coffee oil by GC. The oil content of espresso coffee extract was found to be rich by 16% and the FFA composition was rich in palmitic acid (C16:0 43% by weight) and linoleic acid (C18:2 31% by weight). 31% of FFA was obtained from the coffee oil. Experimental studies have shown that the highest FFA conversion of 88% with 93% TMP tri-ester content was obtained at a temperature of 55°C, 5% enzyme (w/w), non-aqueous media, 3/1 FFA/TMP mole ratio, 500 rpm mixing speed and 24 hours. Implications: Filter coffee wastes, which have become one of the most important biological wastes with an annual production capacity of 6 million tons worldwide; It is targeted to be transformed into environmentally friendly products, as it is important in terms of economy and policies of many developing countries, it is a renewable resource and there is a high amount of waste accumulation day by day. Evaluation of waste filter coffees and oils with this research article; It is envisaged that the bio-lubricating oil used in many sectors will be synthesized and commercialized with an environmentally friendly process.

Polyolester Based Lubricant from Waste Feedstock for Sustainable Environment: A Tribological Investigation

This study reported the tribological evaluation of polyolester based lubricant synthesised from waste feedstock. The transesterification process was adopted for the formulation of lubricant from waste mango seed kernel oil. The polyols used in this formulation are neopentyl glycol, trimethylolpropane and pentaerythritol. The tribological investigation was conducted using four ball tribometer as per ASTM D4172. The frictional and wear behavior of vegetable oil-based polyolester was analysed in addition to the wear morphology of investigated balls. The results indicated that the average frictional torque and mean wear diameter of pentaerythritol ester of waste mango seed oil was 0.12 Nm and 0.403 mm respectively and also found that the pentaerythritol ester showed improved tribological results as compared with other polyolesters say neopentyl glycol ester and trimethylolpropane ester of waste mango seed oil. The waste mange seed oil is found suitable candidate for the formulation of polyolester based sustainable lubricant.

Tribological properties of polyol ester – commercial motorbike engine oil blends

This current study investigates the effect of blending bio-lubricant with commercial lubricant on physico-chemical and tribological properties. The synthesis of TMP and PE ester are optimized to obtain 100% long chain tetra-esters and extreme care was taken during preparation of bio-lubricant to lessen deterioration of physio-chemical properties by blending with commercial oil. SM grade commercial petrol engine oil was blended with Tri-methylolpropane (TMP) ester, Penta-erythritol (PE) ester derived from Calophyllum-inophyllum in 10, 15, 20 and 25% v/v. The tests for anti-wear, anti-friction and extreme pressure properties are conducted on the sample oils on a four-ball wear tester. The friction coefficient and wear of bio-lubricant – commercial oil blends have decreased significantly up to 20% blending percentage. In the extreme pressure test, there is a substantial improvement in the weld load and marked improvement in the load wear index signifying the better load-bearing capacity of commercial oil – bio-lubricant blends. A synergy between bio-lubricant and additives in the commercial oil was found from a metallographic examination of worn balls after the EP test. The optimum volume percent of blend was found to be 15% PE blend and 10% TMP blend for optimum overall performance.

Characterization of Trimethylolpropane‐Based Biolubricant

AbstractThe oxidative stability index (OSI) of fatty acid methyl esters (FAME) and trimethylolpropane (TMP) esters or TMPE produced from five vegetable oils (Brassica rapa L., Linum usitatissimum L., Zea mays L., Brassica napus L., Camelina sativa L.) are compared. The highest stability is observed in vegetable oils while the processed products are less stable. The major causes in loss of OSI are attributed to excess FAME in the crude product and the loss of natural antioxidants due to refinement with silica and celite. The low‐temperature flow properties of TMPE produced from four different vegetable oils (B. juncea L., L. usitatissimum L., B. rapa L., and C. sativa L.) are investigated by proton nuclear magnetic resonance (1H‐NMR). The T2 relaxations of different TMPE are measured to observe how the mobility of oil changed as temperature decreased. Increased oil mobility (represented by T2) is correlated with rising temperature. The Gaussian widths of the singlet in 1H‐NMR spectra of each oil demonstrated increased molecular mobility as temperature increased. Extrapolation of the relation of T2 signals of these four oils indicates that T2 approached zero between 232 K and 239 K, suggesting the molecular motion leading to a T2 relaxation has largely ceased.Practical Applications: The OSI is determined for four vegetable oils as well as the product FAME and TMPE. The vegetable oils are more stable than their products. The loss of natural antioxidants during purification of FAME and TMPE contributes to the lower OSI compared to vegetable oil. The low‐temperature flow behavior of TMP‐based biolubricants is determined between 238 K and 298 K using T2 relaxation. As temperature decreases, a singlet resonance in 1H‐NMR spectra attributed to TMP protons broadens until it disappears. The results suggest that the log of the spin‐spin relaxation time is linearly correlated with rising temperature and oil mobility.

Cottonseed Trimethylolpropane TMP Ester as Lubricant and Performance Characteristics for Diesel Engine

Many researchers have been working on bio-based lubricant which is complete or partial replacement for mineralbased lubricant. Mineral-based lubricant is highly pollutant and possesses environmental threat as it is not biodegradable, in the initial days of the industrial revolution bio-based lubricants were widely used, later it was replaced by more sustainable and easily available but environmental polluting mineral oils, currently due to environmental concerns and scarcity of mineral oils, bio-based lubricant has gained importance. Bio-based lubricants are now a day’s used for various applications such as transformer oil and processes where there is complete loss of lubricants. They possess very good properties in such applications, whereas bio-based lubricants are also used internal combustion engines, pure biobased lubricant may not be suitable for long-duration, but genetically and chemically modified bio-based lubricants will be suitable for IC engine. Though bio-based lubricant possesses many good properties as a lubricant for IC engine and various other application, it is still at large to become commercial, more study is required for checking performance of such pure and modified bio-based lubricants oils, in this paper such study of cotton seed Trimethylolpropane (TMP) ester oil and its effects on performance of brake specific fuel consumption (BSFC), brake thermal efficiency (BTh) and emission of gases like hydrocarbon (HC), carbon monoxide (CO), carbon dioxide (CO2 ) nitrogen oxides (NOx ) are studied, bio-based have poor cold flow properties and oxidation stability to improve these additives are added. The experimental study shows that Cottonseed Trimethylolpropane Ester (CSTE) displays similar characteristics of thermal efficiency, brake specific fuel consumption and emission of gases as compared to mineralbased lubricating oil hence can be used in the IC engine instead of mineral-based lubricants.

Synthesis of Trimethylolpropane Esters by Base‐Catalyzed Transesterification

AbstractTrimethylolpropane (TMP) esters are synthesized from fatty acid methyl esters (FAMEs) and TMP to produce a fluid with properties suitable for use as a lubricant base oil, exhibiting good stability, and low‐temperature performances. In this study, triacylglyceride (TAG) molecules are modified to produce FAME and then linked to TMP. Initially, vegetable oil is transesterified with excess methanol, and potassium hydroxide to produce crude FAME. The FAMEs are then refined and further transesterified with TMP and heating, under vacuum, using potassium carbonate catalyst. The conversion of TMP is successfully achieved by adding an excess of FAME to a reaction mixture of base and polyol in the second step. All reactions are monitored and confirmed using 1H‐NMR. The reactions proceed quickly as an efficient production of FAME and TMP to TMP triesters is successfully achieved by adding an excess of FAME slowly to a mixture of TMP and catalyst.Practical Applications: The major objective is to develop and optimize a reverse addition reaction method for TMP‐based biolubricant production. The highly enriched TMP biolubricant is prepared by reverse phase chromatography and these biolubricant products are characterized for oxidative stability index and low‐temperature performance. The optimum conditions are applied to different vegetable oils.

Effects of palm-based trimethylolpropane ester/mineral oil blending on dielectric properties and oxidative stability of transformer insulating liquid

Blending of palm-based ester can effectively increase the flash point and thermal-oxidative stability of mineral transformer oil especially in the event of high loading and high temperature. Inversely, owing to the excellent dielectric properties of mineral oil, the dielectric properties of the esters can also be improved. Thus, high oleic palm-based trimethylolpropane (TMP) ester was blended and homogenized with 20 to 50 % of mineral oil, and the physico-chemical and electrical properties of each base fluid was compared with that of pure TMP ester and pure mineral oil. The samples were also subjected to oxidative stability test conducted at 95°C for 500 hours, with the presence of water, oxygen and copper/steel catalyst. During ester and mineral oil degradations, the oxidized oils take on dark brown color with the increase in oxidation products concentration and the sludge formation due to the reaction between the oil and the metal catalyst. XRF measurements performed on the samples showed an increase in iron and sulfur contents, which can be explained by the formation of superficial surface layer of iron (II) sulfide or ferrous sulfide. From the investigations, it was found that the 80/20 of ester/mineral oil blending sample have properties near to the standard values for transformer liquid insulation; thus, it can potentially replace traditional mineral oil as an alternate liquid insulation.

Tribological characteristics of Calophyllum ester based bio-lubricant – commercial engine oil blends

The main purpose of this research is to investigate the Tribological characteristics of Calophyllum Ester based Bio lubricant – commercial engine oil blends. The Bio lubricants used in this study are esters derived from Calophyllum seeds. The fatty acid content reveals the presence of saturates which form feed stock to esters. The physicochemical properties evaluated as per ASTM standards are found to be in an acceptable range. TMP (Trimethylolpropane) ester is blended with HP-RACER4 (Engine oil) in 5%, 10%, 15%, and 20% volume percentages respectively and tested for Anti-wear and Anti-Frictional properties using a four-ball tribo-tester. It was found that, although both the esters offer a very low coefficient of friction, the main drawback is their failure at higher loads. The blending of commercial lubricant with bio-lubricant resulted in lower friction and wear characteristics of the commercial lubricant. The optimum percentage of bio-lubricant in the commercial lubricant is found to be 20% which gave the desired results.

Synthesis of trimethylolpropane fatty acid triester as a high performance electrical insulating oil

The trimethylolpropane esters (TME) based high performance electrical insulating oil was synthesized by esterification of the mixture of C6, C8 and C10 acids blend with trimethylolpropane (TMP). The conversion yields of TME is maximized at catalyst (SnCl2) dosage of 0.8 wt.% and the TMP:acid molar ratio of 3.2:1 at 140 °C. The electrical performance is significantly improved by a purpose-oriented purification process which is structured by washing with ultrapure water and absorption with molecular sieve. The obtained insulating oil shows much reduced viscosity (23.3 mm2 s−1) and much enhanced AC breakdown voltage (72.6 kV) comparing with the commercial natural ester insulating oil FR3® (34 mm2s−1 and 63 kV). The high performance of the insulating oil is also manifested by quite low pour point (−45 °C) and high flash point (248 °C) which are superior to those values of mineral insulating oil (−30 °C and 170 °C). The remarkable oxidation stability of the insulating oil is metered by the oxidation induction time (OIT) 2275 min at 130 °C which should be attributed to the elimination of CC double bonds and β-H atoms.

Investigation of tribological properties and engine performance of polyol ester–based bio-lubricant: Commercial motorbike engine oil blends

This article explores the influence of blending polyol ester–based bio-lubricant with commercial lubricant on engine performance. Polyol esters trimethylolpropane ester and pentaerythritol ester were prepared from Calophyllum inophyllum seeds. Extreme care was taken to minimize deterioration of physicochemical properties when blending bio-lubricant with commercial oil. Blending of bio-lubricant with commercial oil was carried out in 10%, 15%, 20% and 25% volume. The test oils were first investigated for wear and friction properties on a four-ball wear tester. Optimum blending ratio was calculated from results of tribological properties, and the blend with optimum blend ratio was investigated for engine performance. The engine performance of the optimum blends was evaluated by conducting a 60-h endurance test on a motorbike. Significant improvement in tribological properties was observed up to a blending percentage of 15% when blending pentaerythritol ester with commercial oil. In the case of trimethylolpropane ester–based bio-lubricant, 10% blending with commercial oil gave optimum performance. The novel evaluation of engine performance of commercial oil and blends has shown a reduction in the wear of engine components with an encouraging decrease in fuel consumption. Metallographic studies conducted on worn piston rings reveal synergy between additives in the commercial oil and esters in the bio-lubricant in reducing wear and friction, thereby reducing fuel consumption.

Friction and wear behavior of karanja oil derived biolubricant base oil

This work deals with the tribological performance of karanja oil trimethylolpropane ester (KOTMPE) biolubricant base oil for its probable application as automotive lubricant. The biolubricant was synthesized by transesterification of karanja oil methyl ester with trimethylolpropane (TMP) under acid catalyst. The study was made with Ducom TR30L four-ball tester at 1200 rev min−1 speed and 75 °C temperature over 60 min duration under normal loads of 15 kg and 40 kg as per ASTM D 4172-94 A and B standard test method. Principal results at two loads are given here: Coefficient of friction (CoF) 0.100 and 0.042, wear scar diameter (WSD) 0.30 mm and 0.44 mm, flash temperature parameter (FTP) 80.932 and 126.249, and thermal energy (TE) 0.054 J and 0.060 J, respectively. The study found that KOTMPE has lowest CoF than any vegetable oil, TMP ester or commercial lubricant. Similarly, the WSD was lowest among all the vegetable oil based lubricants and was at par with SAE 20W-50 and SAE 40 commercial lubricants. FTP was better compared to any vegetable oil or TMP ester. Finally, the energy efficiency of KOTMPE was better than that of other vegetable oils, TMP esters and mineral lubricants. The synthesized ester demonstrated the outstanding performance in terms of friction and wear characteristics along with high thermal stability and energy efficiency worthy of comparison with multiple lubricating products reported by different research groups in available literature during last two decades.

DEVELOPMENT OF TECHNOLOGY FOR PRODUCTION OF PLASTICIZERS ON THE BASIS OF TRIMETHYLOLPROPANE

Polyhydric alcohols - neopolyols and their derivatives due to the nature of the structure have a row of unique properties - high thermal stability, moisture resistance, chemical resistance and are widely used in the production of synthetic oils, resins, varnishes, surfactants and plasticizers. Esters of neopolyols with several ester groups have excellent characteristics at low temperatures, as well as high environmental friendliness, which meets modern requirements. The variation in the production of esters of neopolyols, alcohol and acid components in various combinations allows to obtain a wide range of products with different characteristics and consumer properties. Currently, neopolyol esters are not produced in Russia. However, the technical capabilities of the development of R-Oxo technology based on natural gas are not in doubt, which will allow in the near future to organize its own production of neopolyol esters for the production of high-tech materials. In the present work, the possibility of obtaining plasticizers based on trimethylolpropane esters and C2-C5 acids of various structures was investigated. Samples of 7 trimethylolpropane triesters were synthesized and their certain physicochemical properties were determined. It is shown that the most promising is the synthesis of a plasticizer using acetic acid. Conducted kinetic studies on the esterification of trimethylolpropane with acetic acid. A differential method was used to estimate the reaction rate from the initial consumption rates of acetic acid. The first orders of reaction are determined by alcohol and catalyst under the conditions studied; the value of the observed activation energy of the obtained reaction of the pseudo-second order, in the temperature range of 80-115 °C, was 57.9±8.1 kJ/mol. The results obtained allow us to recommend the conditions for the implementation of the process in the industry.

Investigation on Thermo-Oxidative Stability of Karanja Oil Derived Biolubricant Base Oil

Vegetable oils lack acceptable thermo-oxidative stability due to the presence of tertiary β-hydrogen in glycerol backbone of triglyceride molecule. Chemical modification methods may significantly improve the thermo-oxidative stability of vegetable oils derived biolubricants without hindering their environmentally benign characteristics. This study was aimed at evaluation of thermo-oxidative stability of non-edible karanja oil derived biolubricant base oil. The biolubricant karanja oil trimethylolpropane ester (KOTMPE) was synthesized by conventional two step transesterification process. Thermal stability of synthesized product was assessed by thermogravimetric analysis in non-isothermal mode under nitrogen atmosphere, whereas the oxidation stability was analyzed using Rancimat method. Kinetics of thermal degradation of biolubricant was also investigated by thermogravimetric analysis to obtain order of thermal degradation, activation energy and the frequency factor. The results revealed excellent thermo-oxidative stability for synthesized product at high temperatures with ample scope for further improvement by blending with appropriate additives as demanded by specific applications.

Synthesis of Waste Frying Oil and Trimethylolpropane Based Lubricant Basestocks

Research on waste frying oil based lubricant base stocks production and trimethylolpropane (TMP) was investigated. Quality parameters were tested for the waste frying oil. The hydrolysis process was conducted to extract the free fatty acid from waste frying oil. TMP ester was produced via reaction between free fatty acids of waste frying oil and TMP at 130-140°C, for 5 hours with acid-catalyzed condition. Modification of TMP ester by epoxidation reaction followed by ring-opening reaction using a medium branch chain alcohol; 2-ethylhexanol. The TMP ester was reacted with hydrogen peroxide and formic acid at 45-55°C for 2½ hours during epoxidation process. Epoxidized TMP ester was reacted with 2-ethylhexanol in mol ratio of 1:2 to produce ether ester TMP. Concentrated sulphuric acid was used as a catalyst during ring opening and esterification processes. Ether ester TMP functional groups and chemical structure were identified using FTIR and NMR, respectively. Confirmation with FTIR has indicated sharp peak at 1742 cm-¹, proved the existence of ester group which confirmed the TMP ester formation during esterification and broad peak of 3456 cm-1 during ring opening indicated the formation of ether ester TMP. In ¹H NMR analysis, the signal of methylene proton in which the carbon attached to ether esters TMP existed at 4.0-4.1 ppm and for 13C NMR, the carbonyl ester signals existed in the range of 174.1 ppm. Several analyses were conducted on the ether ester TMP base stock such as hydroxyl value, viscosity value, pour point and flash point. It showed good low temperature behaviour with pour point at -40oC and high thermal stability, flash point value exceeding 250oC and viscosity value of 75 cP. The ether ester TMP produced is comparable with a commercial biolubricant in the market respectively.

Thermal Aging Characteristics of Newly Synthesized Triester Insulation Oil

High-stability triester insulation oil derived from the trimethylolpropane esters (TME) was synthesized by esterifying saturated fatty acids and trimethylolpropane (TMP). The TME oil shows higher AC breakdown voltage (Vb, 72.6 kV/2.5 mm) than that of FR3 (65 kV/2.5 mm). TME oil is readily biodegradable whose biodegradation is 82.2% after 28 days. Pressurized differential scanning calorimetry (PDSC) was applied to measure oxidation onset temperature (OOT) of TME oil for initial evaluating the oxidation stability. Due to the elimination of the carbon-carbon double bonds and β-H, the OOT of the TME oil without antioxidants is approximately 25°C higher than that of FR3. To evaluate the realistic performance of the TME oil, the effect of transformer materials on the aging behavior was investigated. The effect of transformer materials on the thermal aging of TME oil and mineral oil (MO) is less than that of FR3. Although the moisture content and acid value in TME oil induced by aging are higher than those in MO. These acids and moisture do not cause obvious degradation of breakdown voltage and dielectric loss factor, which may be attributed to the high moisture solubility in it.