Experimental Investigation on Palm-Based Oil as Alternative for Biodegradable Power Transformer Oil Application in Malaysia

Most power transformers used petroleum-based oil or so-called mineral oil as insulation. Power transformer oil functions not only as electrical insulation and cooling medium but also to suppress corona and arcing. Over the years, power transformer oil has been widely used because of its high dielectric field strength, low dielectric losses, and long-term performance. However, petroleum-based power transformer oil is non-biodegradable and non-renewable. A serious spill could contaminate soil and water. As a non-renewable source, depletion of the source will further increase the price. These have encouraged researchers to look for alternative power transformer oil for better sustainability. Palm-based oil has been seen as a potential substitute, because, it is environmentally friendly, biodegradable and renewable. However, a lot of studies need to be carried out before it can be used as alternative power transformer oil commercially. Thus, this work has been carried out to investigate several electrical and physical properties of palm-based transformer oil, such as breakdown voltage, partial discharge characteristics, kinetic viscosity, and flash point. The effect of ageing on electrical properties of the palm-based oil has also been investigated. Two types of palm-based oil, namely Palm Fatty Acid Ester (PFAE) and Refined, Bleached, Deodorized Palm Oil (RBDPO) have been selected in this work. As a comparison, the commercially available soy-based biodegradable oil is also investigated for assessment and further analysis purpose. The results revealed that PFAE and RBDPO have great potential as power transformer insulation because of their good insulating characteristics as commercially available biodegradable oil

Synthesis of schiff base hydrazone from palmitic hydrazide and corrosion inhibitory properties via electrochemical methods

In view of the emerging importance of non-toxic and green corrosion inhibitors to replace chromate (CrO42-), molybdenate (MoO3-), nitrate (NO2-) and silicate (SiO44-)in protecting metallic surfaces in acid pickling for metal processing industry, acidified oil wells and boiler cleaning process; researchers have recently focused on organic corrosion inhibitors. Schiff bases are amongst the molecules of choice that are able to exhibit corrosion inhibitory activities and have been predominantly investigated as corrosion inhibitors for numerous metals in various acidic media. The lone pair electrons and π-electrons at imine bond may interact with d-orbital of metal through electron donation and forms a layer. This layer protects the metal surface from being attacked by corrosive species. The objectives of this study are firstly to synthesize Schiff base hydrazones (SBHs) from palmitichydrazide and various aldehydes; and secondly to investigate inhibitive activities of those SBHs on mild steel in acid solution via electrochemical method. Eight SBHs were successfully synthesized from PH and various aldehydes containing linear alkyls, branched alkyl and aryls through one-pot synthesis. Commonly, acid catalyst is required in the synthesis of Schiff base as to increase electrophilicity of carbonyl for aldehyde and to allow dehydration to form Schiff base; and an efficient water removal system is applied to improve conversion. In this study, SBHs were prepared by heating the reactants in dimethyl form amide at 90oC for 2 hours without using any acid catalyst. Opportunely, SBHs with high yields (92-100%) and high purity (92-99%) were successfully obtained. The effect of solvent used, reactant mol ratio and reaction time on synthesis of SBHs were also investigated. Chemical characterization was conducted using gas chromatography, Fourier trans formed-infrared (FT-IR), CHN elemental analysis, 1H and 13C nuclear magnetic resonance and gas chromatography-mass spectroscopy. . The inhibitory properties were examined on mild steel (MS) coupons in 1 M HCl solution with concentration varied from 25, 50, 75, 100 and 200 mg/L at temperature ranged from 25 to 55oC using electrochemical techniques: linear polarization and electrochemical impedance spectroscopy as well as surface analysis using scanning electron microscopy-energy dispersive x-ray (SEM-EDX). The presence of studied inhibitors had shown appreciable inhibition efficiency (IE%) in which the increment of IE% values exceed 50% when the concentration of inhibitor and temperature were increased from 25 to 200 mg/L and 25 to 55oC, respectively. The adsorption of SBHs onto the MS surface obeyed the Langmuir adsorption isotherm with the standard free energy of adsorption (ΔGads) of between -31 and -43 kJ/mol. According to these values, these SBHs adsorbed spontaneously onto MS surface through both physisorption and chemisorption processes. Other thermodynamic parameters such as activation energy (Ea), entropy of adsorption (ΔSads),enthalpy of adsorption (ΔHads),enthalpy of activation (ΔHo) and entropy of activation (ΔSo) were also determined. SEM-EDX analysis was conducted on MS coupons after immersing in 1 M HCl solution and inhibited 1 M HCl solution containing 200 mg/L for 3 hours and 30 days. In general, significant changes of MS surface were clearly seen after 30 days of immersion. Smooth surfaces with invisible of scratch lines were observed for MS coupons obtained from experiments containing SBHs except for SBHs with a branched alkyl (HB1) and phenyl with methoxy group (HA2). In EDX analysis, significant differences in ferum, chlorine and oxygen contents were observed for MS coupons that were immersed in blank and inhibited solutions containing PH and HB1 that probably attributed to the formation of corrosion products like FeCl2and Fe(OH)2.All SBHs except for solutions containing HB1 and HA2 showed inhibitory properties that better than PH. This could be due to the lone pair of electrons on the nitrogen at imine and heteroatoms of SBHs structures. These electrons allow them to efficiently adsorb onto metal surface thus inhibiting the surface. Branching effect and incapability of phenyl group to lay flat orientation on the MS surface for HB1 and HA2 molecules, respectively could be the main reasons for these two inhibitors did not perform well as corrosion inhibitors

Method to produce hydrazone from hydrazide

The present invention provides a method to produce hydrazone from hydrazide. The method includes steps of mixing a hydrazide with an aldehyde in a reaction device, adding an organic solvent forming a mixture, stirring the mixture at a oredetermined speed and a predetermined temperature for a predetermined period of time, carrying out reaction under a reflux system wherein condenser used in the reflux system is equipped with a circulating bath forming a reaction product, cooling the reaction product at an ambient temperature after the completion of reaction, adding a non-reacting liquid to the reaction product to form a white paste produiuct, conducting filtration on the white paste product to produce a dried white-solid product, recrystallizing the dried white-solid product from dimethylformamide, adding 30 to 50 mL of an organic solvent which has been heated to a temperature of between 40C to 80C to the dried white-solid product to obtain a clear solution, adding between 5 to 15mL of a non-reacting liquid to allow formation of a white paste hydrazone and conducting filtration on the white paste hydrazone to obtain dried white-solid product

Corrosion inhibition of mild steel in hydrochloric acid solution using fatty acid derivatives

The inhibitive actions of fatty acid derivatives namely palmitate hydrazide (PH), N-ethylidene palmitate hydrazide (EPH) and N-phenylmethylidene palmitate hydrazide (PPH) on mild steel in 1 M hydrochloric acid were investigated using open circuit potential, linear polarisation and electrochemical impedance spectroscopy techniques. It was observed that the percentage of inhibition efficiency (η%) increased with increasing concentrations of inhibitor and temperature of test medium. The maximum η% approaches 85% in the presence of 200 mg litre-1 of inhibitors EPH and PPH at 308 ± 1K. The inhibitor efficiencies were found to be in the following order: PPH>EPH>PH. The adsorption of these inhibitors on mild steel surface obeys Langmuir adsorption isotherm. They act as mixed-type inhibitors. Scanning electron microscopy-energy dispersive X-ray (SEM-EDX) was also carried out on polished mild steel coupons and those immersed in the test medium with the absence and presence of 200 mg litre-1 of the inhibitors studied

Corrosion inhibition, adsorption and thermodynamic properties of hydrophobic-tailed imines on carbon steel in hydrochloric acid solution: a comparative study

Three hydrophobic-tailed imine compounds containing linear alkyl, branched alkyl and phenyl groups adjacent to the imine bond namely N-propylidenehexadecanehydrazide (PHH-L), N'-(2,2-dimethylpropylidene)hexadecanehydrazide (DMPHH-B) and N-phenylpropionalidene hexadecanehydrazide (PPHH-A), respectively were successfully synthesized with good yields and high purity. Inhibition properties were evaluated with the corrosion of carbon steel in 1 M HCl solution by electrochemical measurements and scanning electron microscopy-energy dispersive x-ray (SEM-EDX). Potentiodynamic polarization measurement indicates that the synthesized inhibitors were effective mixed-type inhibitors and adsorbed on the carbon steel surface following the Langmuir adsorption isotherm with the free energy of adsorption, ΔGoads values ranging from −37.9 kJ mol−1 to −39.5 kJ mol−1 by mixed absorption involving both physisorption and chemisorption. Impedance spectroscopic analysis revealed that the inhibitors reduced the corrosion process by a charge-transfer process. SEM-EDX analysis revealed that the corrosion damage of the carbon steel surface was reduced in the presence of the inhibitors containing linear alkyl (PHH-L) and phenyl (PPHH-A) groups. In contrast, DMPHH-B, a compound with a branched alkyl group increased corrosion damage

Effect of water on electrical properties of refined, bleached, and deodorized palm oil (RBDPO) as electrical insulating material

This paper describes the properties of refined, bleached, deodorized palm oil (RBDPO) as having the potential to be used as insulating liquid. There are several important properties such as electrical breakdown, dielectric dissipation factor, specific gravity, flash point, viscosity and pour point of RBDPO that was measured and compared to commercial mineral oil which is largely in current use as insulating liquid in power transformers. Experimental results of the electrical properties revealed that the average breakdown voltage of the RBDPO sample, without the addition of water at room temperature, is 13.368 kV. The result also revealed that due to effect of water, the breakdown voltage is lower than that of commercial mineral oil (Hyrax). However, the flash point and the pour point of RBDPO is very high compared to mineral oil thus giving it advantageous possibility to be used safely as insulating liquid. The results showed that RBDPO is greatly influenced by water, causing the breakdown voltage to decrease and the dissipation factor to increase; this is attributable to the high amounts of dissolved wate