Development of palm - based neopentyl glycol diester as dielectric fluid and its thermal aging performance

The potential of palm-based neopentyl glycol diester as dielectric insulating fluid was investigated. The details of the transesterification of high oleic palm oil methyl ester (POME) with neopentyl glycol (NPG) with the final product yield of more than 90 wt% of NPG diester were discussed. The thermal aging performance of NPG diester was compared with conventional mineral insulating oil at 90, 110 and 130 °C. This paper focused mainly in the effects of aging to chemical, physical and electrical properties of NPG diester. Apart from being fully biodegradable and non-toxic, the synthesized diesters exhibited high flashpoint and the breakdown voltage was comparable to mineral oil. The result indicated that throughout the aging period, NPG diester exhibited lower acid value than mineral oil and no significant change in viscosity was observed. The study on mechanical properties of insulating paper aged in NPG diester shows higher tensile strength than paper aged in mineral oil. The synthesized esters have shown great potential to be used as transformer oil

Prospects of Plant-Based Trimethylolpropane Esters in the Biolubricant Formulation for Various Applications: A Review

Biodegradable lubricants from renewable feedstocks have been successfully developed to meet the demands of new machines with stringent requirements of the global standards, which address sustainability and environmental policy. Trimethylolpropane ester (TMPE) has been extensively evaluated as a biolubricant base stock and occasionally used as an additive, due to their low toxicity and excellent biodegradability. The formulation of high-performance TMPE-based lubricants involves addition of surface additives, multifunctional additives, and solid nano particles. This review focuses on the development of plant-based TMPE formulation for various applications, namely food-grade lubricant, engine oil, drilling fluid, insulating fluid, metal working fluid, hydraulic and heat transfer fluids. Even though plant-based TMPE lubricants have huge advantages over mineral oils, they have other challenging issues such as limited load-bearing capacity, hygroscopic properties, and high risk of toxic emission owing to additives selection. The details on the performance characteristics of TMPE as base stocks and additives are discussed, including the current prospects and challenges in the respective areas. This review concludes with a brief discussion on suggestions and recommendations for future advancement in the usage of TMPE and the remaining issues that must be overcome to allow for its full potential to be realized

Kinetic study on the production of biodegradable lubricant by enzymatic transesterification of high oleic palm oil

Kinetic studies are necessary to identify inhibitors of lipase enzyme deactivation in reaction systems because varying substrate concentrations can affect the enzyme's catalytic activity. The present study aimed to analyze the reaction kinetics of palm-based polyol ester production catalyzed by commercial lipase Novozyme 435 (N435). The enzymatic transesterification reaction was performed in a solvent-free medium. The effect of substrates concentration, specifically high oleic palm methyl ester (HO-PME) and trimethylolpropane (TMP), on the kinetic constant was studied at the initial reaction rate. The study was conducted based on the Ping-pong Bi-bi model, assuming that both substrates could inhibit the reaction. The reaction was carried out at 70 °C and 15.25 mbar with a 3 % (w/w) N435 enzyme load to investigate the effect of various HO-PME and TMP concentrations. The kinetic constants obtained are as follows: = 61.112 mol/L, = 0.336 mol/L, = 0.002 mol/L, = 2.415 mol/L and = 17.24 mol/L.hr. The results implied that N435 has higher affinity towards TMP than HO-PME. Inhibition constant indicated a lower inhibitory function of the TMP than HO-PME ( > ). The reaction kinetics obtained in this study agreed well with the model used with TMP and HO-PME as competitive inhibitor during enzymatic transesterification

Development of Supersurfactant for Enhanced Oil Recovery Application

Surfactant flooding is a form of chemical enhanced oil recovery (EOR) that can allow operators to extend reservoir pool life and extract incremental reserves currently inaccessible by conventional EOR techniques such as water flooding. A very low concentration of the surfactant can be used to achieve ultra low interfacial tension between the trapped oil and the injection fluid/formation water. Addition of a surfactant lowers the interfacial tension between water and oil which helps to reduce capillary pressure in the reservoir. Many petroleum formations contain water having high salinity and are additionally at temperature from about 30°C to about 150°C. Most surfactants suitable for use in oil recovery operations are either not effective in high salinity or cannot tolerate the higher temperatures encountered in many such formations. The objective of this research was to develop a systematic laboratory screening and design a high performance chemical formulation that can be used for challenging reservoirs that have high salinity and also high temperature. Aqueous and microemulsion phase behavior tests have previously been shown to be a rapid, inexpensive and highly effective means to select the best chemicals and minimize the need for relatively expensive core flood tests. Aqueous stability test, interfacial tension (IFT) measurement and phase behavior tests were therefore done with various combinations of surfactants and alkali for several reservoir conditions including the challenging reservoir of interest which is Dulang Oil Field. Extensive laboratory screening identified potential chemical formulations that give the lowest IFT for the targeted reservoir

Characteristics of polyol ester as transformer insulating oil

Mineral-based transformer oil has long served the purposes of insulating and cooling in an electrical power transformer. However, its low flash and fire point constitute a high risk for fire and explosion and not suitable to be used in densely-populated and environmentally sensitive areas. The overall objective of this study is to develop an environmentally friendly polyol ester that is practical and suitable for the transformer application. Specifically, the effect of polyol esters with different chemical structures on the electrical properties and oxidative degradation were investigated. Different chemical structures that can be produced from the transesterification of various methyl esters (C8/C10, C12 and C18) with neopentylglycol (NPG)/ trimethylolpropane (TMP) alcohols were synthesized and compared with those of commercial synthetic ester PFAE and mineral oil. Based on the evaluation of physicochemical and electrical properties, TMPE C18 exhibited the most optimum insulation properties with excellent flash point and moisture content, excellent breakdown voltage, relative permittivity, dissipation factor and resistivity. Experimental investigations on the oxidative characteristics and catalytic effects of copper/iron on different esters were also conducted by using the turbine oil oxidation test (TOST). The unadditived TMPE C18 ester showed a comparable oxidative performance to the commercial ester PFAE and the most viable option for ester-based transformer oil. TMPE C18 exhibited high stability against oxidation by having almost similar oxidation lifetime as PFAE, maintains low acidity even after oxidation duration and does not corrode copper or iron. The effects of different ester and mineral oil blending composition were further investigated to improve the current properties of base oil. C18 TMPE sample was blended and homogenized with 20 to 50% of mineral oil. It was found that the 20MO (80/20 of C18 TMPE/mineral oil) blending sample has the properties near to the standard values for transformer liquid insulation. The effects of different antioxidants were studied too. Blends containing Irganox L57 antioxidant showed a remarkable oxidation lifetime compared with other antioxidants. However, the use of Irganox L57 contributed to increased concentration of copper and iron after oxidation in oil thus gives comparable performance to untreated 20MO blend. The thermal aging behavior of insulating paper aged in unadditived 20MO blend at 110, 130 and 150°C for 14, 28, 42, 56 and 84 days were evaluated and compared with that of mineral oil. The overall results showed that paper aged in mineral oil degraded significantly faster than in the 20MO blend. The kinetics study on the Kraft paper degradation predicted the loss of tensile strength and degree of polymerization aged in blend and mineral oil and the proposed kinetics model fitted well with the experimental data. The blend showed good thermal ageing characteristics compared to the conventional mineral oil

Development of Supersurfactant for Enhanced Oil Recovery Application

Surfactant flooding is a form of chemical enhanced oil recovery (EOR) that can allow operators to extend reservoir pool life and extract incremental reserves currently inaccessible by conventional EOR techniques such as water flooding. A very low concentration of the surfactant can be used to achieve ultra low interfacial tension between the trapped oil and the injection fluid/formation water. Addition of a surfactant lowers the interfacial tension between water and oil which helps to reduce capillary pressure in the reservoir. Many petroleum formations contain water having high salinity and are additionally at temperature from about 30°C to about 150°C. Most surfactants suitable for use in oil recovery operations are either not effective in high salinity or cannot tolerate the higher temperatures encountered in many such formations. The objective of this research was to develop a systematic laboratory screening and design a high performance chemical formulation that can be used for challenging reservoirs that have high salinity and also high temperature. Aqueous and microemulsion phase behavior tests have previously been shown to be a rapid, inexpensive and highly effective means to select the best chemicals and minimize the need for relatively expensive core flood tests. Aqueous stability test, interfacial tension (IFT) measurement and phase behavior tests were therefore done with various combinations of surfactants and alkali for several reservoir conditions including the challenging reservoir of interest which is Dulang Oil Field. Extensive laboratory screening identified potential chemical formulations that give the lowest IFT for the targeted reservoir

Development of palm-based neopentyl glycol diester for transformer oil application

Transformer oil plays an important role as electrical insulator of transformers. Mineral-based transformer oil has relatively high toxicity, low biodegradability and low fire point. The use of vegetable oils has constraints because the presence of beta-hydrogen in its structure renders it susceptibility to oxidation. The polyol esters have a unique feature that can overcome the oxidation problem faced by the vegetable oils. Hence the focus of this project is to study the potential of neopentyl glycol (NPG) diesters to be used as transformer oil. The synthesis of NPG diester was successfully optimized via transesterification of palm oil methyl ester (PME) with neopentyl glycol. The present study investigated the application of low-pressure technology as a new synthesis method which is able to shorten the reaction time. The optimum reaction conditions obtained by manual and response surface methodology (RSM) optimization were molar ratio of 2:1.3, reaction time of 1 hour, temperature at 182°C, pressure at 0.6 mbar and catalyst concentration of 1.2 wt%. The ester exhibited better properties than the commercial transformer oil especially with regards to the breakdown voltage, flash point and moisture content. The synthesized NPG diester was then formulated with anti-oxidant and pour point depressant to enhance its oxidative stability and low temperature properties. While 2,6-di-tert-butyl-p-cresol (DBPC) has proven to be useful and effective anti-oxidant for mineral oil, present studies indicate that it is not suitable to be used as additive in NPG diester, or in polyol ester as general. The pour point depressant on the other hand, has successfully increased the pour point of NPG diester from -14°C to -48°C. The laboratory thermal aging studies have also been developed to study the effect of temperature and aging time on selected properties and were compared with commercial mineral and refined, bleached and deodorized palm oil (RBDPO) at 90°C, 110°C and 130°C. It was found that aging has profound effect on the moisture content and acidity of the oil due to degradation of both oil and insulating paper. The result indicated that throughout the aging period, NPG diester exhibits low acid value and no significant changes to viscosity and breakdown voltage. The study on tensile properties of insulating paper aged in NPG diester at 130°C shows higher tensile strength than paper aged in mineral oil and RBDPO. The aging rate calculated based on tensile strength indicated that at high temperature, insulating paper degraded faster in mineral oil and RBDPO than in NPG diester. The synthesized NPG diester has high potential to be used as transformer oil

Effect of molecular structure on oxidative degradation of polyol ester

An experimental investigation was conducted to explore the thermal and heat flow characteristics of polyol esters with different molecular structures by using simultaneous thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) measurement. A significant difference in onset temperature between the developed esters and mineral oil was observed. The comparison of oxidative stability of polyol esters and mineral transformer oil revealed that polyol esters are oxidatively stable up to >370°C while for mineral oil it was <300°C. As oxidative degradation starts at a lower temperature than thermal degradation, determination of oxidative stability is more important to study the potential the ester to be used as dielectric fluid

Effect of molecular structure on oxidative degradation of ester based transformer oil

Methyl esters of coconut, palm kernel and palm oils were transesterified with 2-ethylhexanol, trimethylolpropane or neopentylglycol to produce monoester and polyol esters in this study. Experimental investigations were conducted to explore the thermal-oxidative characteristics and catalytic effects of copper/iron on monoester and polyol esters by using the turbine oil oxidation test. Thermogravimetric analysis and differential scanning calorimetry were also performed to evaluate the thermal and oxidation onset temperature. Among the structural trends that improved the oxidative stability include increasing carbon chain length and presence of monounsaturated as opposed to saturated fraction. The study revealed that the presence of copper accelerated the degradation of certain polyol esters. Also, polyol esters are found to be thermally more stable than mineral transformer oils