Chemical modification of waste cooking oil for the biolubricant production through transesterification process

Concerns and restrictions around contamination and environmental pollution are developing. The production of waste cooking oil and the pollution brought on by mineral oils are two important issues. The FSSAI's new standards state that cooking oil that contains more than 25% polar compounds is inappropriate for use and should be discarded. Therefore, both issues can be resolved with the aid of chemical modifications to waste cooking oil. Waste cooking oils are an attractive alternative to mineral oils because they are biodegradable and renewable sources of lubricants. The goal of the current research work is to create an environmentally friendly lubricant through transesterification reaction. Fatty acid methyl esters (FAMEs) of WCO with various alcohols (1-Heptanol, 2-Ethyl-1-Hexanol & Neopentyl Glycol) with diverse branching were used to create bio lubricant. As a heterogeneous catalyst, zinc acetate was used to carry out the reaction. Complex esters, which have been produced, have the potential to be used as biodegradable lubricants in industrial lubricant applications. Using the GC-MS technique, the structure of the generated bio lubricant was examined. The structural modification of waste cooking oil resulted in improvement in both physicochemical and tribological properties. The created bio lubricant had improved flash and fire points as well as a superior viscosity index (>120). The generated bio lubricant possesses friction characteristics that are comparable to those of commercial mineral oil-based lubricants. According to the results of this study, waste cooking oil lubricant has a lot of potential for use as a base stock due to its favorable biodegradability and tribological performance.     

Microalgae Biomass as a New Potential Source of Sustainable Green Lubricants

Lubricants are materials able to reduce friction and/or wear of any type of moving surfaces facilitating smooth operations, maintaining reliable machine functions, and reducing risks of failures while contributing to energy savings. At present, most worldwide used lubricants are derived from crude oil. However, production, usage and disposal of these lubricants have significant impact on environment and health. Hence, there is a growing pressure to reduce demand of this sort of lubricants, which has fostered development and use of green lubricants, as vegetable oil-based lubricants (biolubricants). Despite the ecological benefits of producing/using biolubricants, availability of the required raw materials and agricultural land to create a reliable chain supply is still far from being established. Recently, biomass from some microalgae species has attracted attention due to their capacity to produce high-value lipids/oils for potential lubricants production. Thus, this multidisciplinary work reviews the main chemical-physical characteristics of lubricants and the main attempts and progress on microalgae biomass production for developing oils with pertinent lubricating properties. In addition, potential microalgae strains and chemical modifications to their oils to produce lubricants for different industrial applications are identified. Finally, a guide for microalgae oil selection based on its chemical composition for specific lubricant applications is provided.     

A review on bio-lubricants from non-edible oils-recent advances,chemical modifications and applications

The necessity for lubricants has increased recently, and today's chief issue is the depletion of fossil resources, which drives up the cost of lubricants made of petroleum. As a result, current research focuses on lubricants that are made from renewable resources and are therefore environmentally benign. We can use inedible plant oils as the foundation for biodegradable bio lubricants. The locally accessible seed oils have significant uses in agriculture and nutrition, but more recently, their use in biolubricants and chemical feedstocks has increased. They are favourable to mineral-based counterparts and prospective commodities because of their unique qualities, such as lubricity, biodegradability, reduced toxicity, and reduced volatility. However, while being chemically altered, they still have rather poor cold-flow and thermo-oxidative stability concerns, which restricts their use as lubricants. To get around this restriction, numerous chemical changes have been documented, including transesterification, epoxidation, and estolide ester synthesis, all of which are covered in this paper. The current state and anticipated future trends of the global lubricant market are presented in this review. The primary goal of the current study is to provide an overview of recent non-edible plant uses in biolubricant synthesis. This study contains a review of recent research literature on the utilisation of various non-edible plant oils to create biolubricants.     

餐厨废油制备的生物基两性表面活性剂的油水界面性能

以餐厨废油制备了生物基两性表面活性剂,应用界面张力和动态光散射方法,研究了该生物基两性表面活性剂体系的油水界面性能及在溶液中的聚集行为。 在无外加碱条件下,由餐厨废油制备的表面活性剂表现出良好的界面性能,在50~70 ℃以及pH值为7~12的条件下,均可以将油水界面张力降至超低值(<10^-3 mN/m),在不同的油藏模拟地层水中均保持较好的界面活性;分别在50、-20和4 ℃下保存,其界面活性均未受到明显影响。 在水溶液中形成的聚集体的平均流体力学半径为10~30 nm,无机盐离子的加入可使聚集体的粒径上升。 基于其优良的界面性质和可再生来源,由餐厨废油制备的生物基两性表面活性剂在三次采油方面具有重要的应用价值。     

Lubricant properties of Moringa oil using thermal and tribological techniques

The increasing application of biobased lubricants could significantly reduce environmental pollution and contribute to the replacement of petroleum base oils. Vegetable oils are recognized as rapidly biodegradable and are thus promising candidates for use as base fluids in formulation of environment friendly lubricants. Although many vegetable oils have excellent lubricity, they often have poor oxidation and low temperature stability. Here in, we report the lubricant potential of Moringa oil, which has 74% oleic acid content and thus possess improved oxidation stability over many other natural oils. For comparison, Jatropha oil, cottonseed oil, canola oil and sunflower oil were also studied. Among these oils, Moringa oil exhibits the highest thermo-oxidative stability measured using PDSC and TG. Canola oil demonstrated superior low temperature stability as measured using cryogenic DSC, pour point and cloud point measurements. The friction and wear properties were measured using HFRR. Overall, it was concluded that Moringa oil has potential in formulation of industrial fluids for high temperature applications. Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.     

Lubricants from renewable energy sources – a review

Lubricant oils are known to decrease the friction coefficient between two contacting surfaces. It is essential for the correct function of almost the totality of mechanical machinery working in the entire world. Lubricant oils consist of about 80% of oily base stocks which attributes to their properties of viscosity, stability, and pour point to the lubricant plus additives supplemented to improve these properties. Petroleum lubricants are usually environmentally unacceptable due to their low biodegradability and toxicity. These oils contaminate the air, soil, and drinking water and affect human and plant life to a great extent. Thus, the demand for environmentally acceptable lubricants is increasing along with the public concerns for a pollution-free environment. Plant oils are promising as base fluid for biolubricants because of their excellent lubricity, biodegradability, viscosity–temperature characteristics, and low volatility. The purpose of this paper is to present a survey of the current status of biolubricating oil. This research provides an overview on the synthesis, tribochemical behavior; the effect of structure on friction/wear, load-bearing capacity, resistance to rise in specimen temperature, and varying response of antiwear/extreme-pressure additives in the presence of vegetable oil/derivative structures has also been discussed. Though a significant number of papers have been published in this area, there is still much to explore. A proper selection of base oil and additives is therefore essential for an efficient synthesis of biolubricating oil.     

Environmentally Friendly Recovery and Characterization of Oil from Used Engine Lubricants

The present paper demonstrates the review of some acid processes as well as development of some new solvent processes for reclamation of used lubricating oils. The conventional processes are found to be of low yield (? 50%), laborious, time consuming and environmentally hazardous, because of residual acidic sludge. Based on the findings, a new modified Aluminium sulphate‐sodium silicate‐acid‐base method employing a small quantity of acid and giving a high yield (? 60%) is proposed. Further, to avoid use of acid, new regeneration processes based on solvent extraction were investigated. They are termed CCl₄‐alcohol method, Dodecane‐alcohol method and Toluene‐alcohol method. These processes are not only cost effective in terms of complete solvent recovery, but are rapid, less time consuming, more environmentally friendly and gave a high yield (70–75%). The virgin lubricants (Castrol GTX and Rimula‐C) as well as oils recovered by different methods were also characterized physicochemically to determine kinematic viscosity, density, refractive index, carbon distribution, wear scar diameter, % Conradson carbon residue, % ash, % chloride, pour point, etc. Results obtained show that many of the physico‐chemical properties of the recovered oils are in good agreement with those of virgin oils. The n.d.M analysis was also performed which shows that virgin oils have 73 ± 3% paraffinic carbon, 26 ± 3% naphthenic carbon and about 1% aromatic carbon. The recovered oils also showed nearly the same chemical composition. The UV‐Visible spectra of the recovered oils are all similar to those of virgin lubricants. The results suggest that the oils recovered by solvent treatments, particularly Dodecan‐alcohol and Toluene‐alcohol methods, may serve for lubrication purposes and can be rendered as excellent as virgin lubricants with the addition of certain additives. The proposed methods may be considered as alternative cost effective green techniques for acid reclamation processes and being the motivation of the present investigation.     

Liquid Space Lubricants Examined by Vibrational Microspectroscopy

Abstract

Considerable effort has been expended to develop liquid lubricants for satellites and space exploration vehicles. These lubricants must often perform under a range of harsh conditions such as vacuum, radiation, and temperature extremes while in orbit or in transit and in extremely dusty environments at destinations such as the moon and Mars. Historically, oil development was guided by terrestrial application, which did not provide sufficient space lubricants. Novel fluids such as perfluorinated polyethers provided some relief but are far from ideal. With each new fluid proposed to solve one problem, other problems have arisen. Much of the work performed at National Aeronautics and Space Adminstration's (NASA) Glenn Research Center, in elucidating mechanisms by which chemical degradation of space oils occur, has been done by infrared and Raman microspectroscopy, which this review details. Fundamental lubrication studies are presented as well as actual case studies, in which vibrational spectroscopy led to millions of dollars in savings and potentially prevented loss of mission.     

Modelling relation between oxidation resistance and tribological properties of non-toxic lubricants with the use of artificial neural networks

The lubricants based on vegetable oils, as environmental friendly, are urgently sought. However, in addition to ecological characteristics, the lubricating properties have to be met. To meet these requirements the active additives influencing the lubricating properties and oxidation resistance are used. The useful lifetime of lubricants is determined largely by their abilities to resist oxidation. The article presented the results of new, ecological lubricants development. The oxidation performances of different developed lubricants have been tested. The experimentally determined oxidation stability of the compositions based on vegetable oils are presented. Analysed oxidation onset temperature was obtained from the differential scanning calorimetry (DSC) curves, which provides the rapid prediction of the oxidative stability of lubricants. Besides the lubricating composition based on vegetable oils, the developed greases-based mineral, or synthetic oil were investigated. The properties of these greases were evaluated using the measurement of parameters describing structure (penetration) and resistance to high temperature (dropping point). The lubricating properties of both the greases and vegetable oil compositions were tested on four-ball testing machine. In the results of the modelling of the lubricating properties the neural network models for the both types of the lubricants were developed. A discussion of the research results and analysis of models validity is given below. The experimental results are compared with the calculated using the neural models. An acceptable agreement was achieved.     

Characterization of Silver Flake Lubricants

There is a thin layer of organic lubricant on commercial silver (Ag) flakes that are widely used as the fillers in electrically conductive adhesives (ECAs). This lubricant layer highly affects the properties such as conductivity of the ECAs. Therefore, understanding the behavior of Ag flake lubricant layer is essential for developing high performance ECAs. This work is aimed at studying the chemical nature of the lubricant layer, interaction between the lubricant layer and Ag flakes, and thermal behavior of the lubricants during heating. A blank Ag powder is ball-milled into Ag flakes with five fatty acids that have different carbon–hydrogen chain length as lubricants. After lubrication, the Ag flakes are studied using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetry (TG), and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). It is found that (i) Ag flakes lubricated with fatty acids of different chain lengths have exothermic DSC peaks and mass losses at different temperatures, (ii) the lubricant layer on the lubricated Ag flake surfaces is a salt formed between the acid and Ag, and (iii) exothermic DSC peaks (in air) of a lubricated Ag flake is probably due to the oxidation of lubricant layer on the Ag flake surface. This revised version was published online in July 2006 with corrections to the Cover Date.     

Comparative study of the oxidative and thermal stability of vegetable oils to be used as lubricant bases

Demand for lubricating oils is increasing in the growing Brazilian economy. The use of vegetable bases in exchange of minerals can bring socio-economic and environmental benefits for Brazil. The purpose of this study is to compare the thermal and oxidative stability of vegetable oils related to the bases commonly used as lubricants. In this study, thermogravimetric analysis of castor oil, cotton oil, macauba’s almond oil, passion oil, paraffinic mineral oil, naphthenic oil (NH-140) and synthetic oil (Etro) was performed in inert and oxidative atmosphere to study the thermal and oxidative degradation of the vegetable oils related to the most common lubricants’ oils base. These oils’ oxidation stability were determined by standard procedures (ISO 6886). The use of mineral oil’s additives in these vegetable oils was tested to verify the viability of these additives to improve the oxidative stability of the vegetable oils. The castor oil and the cotton oil presented results of thermal analysis similar to the mineral and synthetic bases values. The castor oil was the only vegetable oil that showed a great oxidative stability. All other vegetable oils had their oxidative stability significantly increased by the additives.     

生物基环氧树脂及固化剂研究现状

生物基高分子材料以可再生资源为主要原料,它在减少塑料行业对石油资源消耗的同时,也减少了石油化工原料在生产过程中对环境的污染,具有节约石油资源和保护环境的双重功效。桐油和松香是我国两种重要的天然可再生资源,在目前将化工原料逐步转向可再生资源的时代背景下,它们已被广泛应用于高分子材料的合成和改性。生物基热固性树脂是一个意义重大且前景广阔的研究领域,本文就桐油和松香在生物基环氧树脂和固化剂方面的应用进行了系统的综述和展望。     

Effect of temperature on friction and wear behaviors of polyimide (PI)‐based solid–liquid lubricating materials

The tribological properties of polyimide (PI) under four oils (including two perfluoropolyether oils and two silicon oils) lubricated conditions were comparatively investigated at room temperature in vacuum and Fomblin M30 and chlorine‐containing silicon oil were selected to study the friction and wear behaviors of PI‐based solid–liquid lubricants against steel at different temperatures in vacuum. Significant improvement in tribological performance of PI was found under oil‐lubricated conditions. The friction coefficient increased as the test temperature decreased for the mobility of liquid lubricant was limited at lower temperatures, while the wear rate exhibited distinct rule. Besides, no tribochemical reaction was detected at the contact surface of PI and chlorine‐containing silicon oil. However, the –CF₃ and fluorinated C? O groups were detected on the worn tracks of PI/Fomblin M30 by X‐ray photoelectron spectroscopy, which indicated that tribochemical reaction happened to PI and Fomblin M30 under high temperature as well as the simulation of friction heat. Copyright © 2015 John Wiley & Sons, Ltd.     

Polymer additive analysis by pyrolysis-gas chromatography. III. Lubricants

Lubricants are widely used in thermoplastic polymers to increase the overall rate of processing or to improve surface release properties. Because of the low level of lubricants normally used in a polymer, it may not be possible to analyze the additive directly by common spectroscopic or thermal chemical techniques. However, lubricants as well as other additives in the polymer can be qualitatively analyzed by pyrolysis-gas chromatography (Py-GC) after extraction. In this work, several lubricants have been studied to demonstrate that Py-GC is a viable tool to investigate lubricants. The advantages of using Py-GC in the analysis of lubricant have also been discussed.     

Preparation and Tribological Behaviors of Lubricants—Oil Based on Modified Microbial Oil with Nano-Schiff Base Copper Complex

A W/O microemulsion reactor was used to prepare four kinds of modified lubricants: (i) modified lubricant 1, modified epoxidized microbial oil + rape oil in volume ratio of 1:1; (ii) modified lubricant 2, modified esterified microbial oil + rape oil in volume ratio of 1:3; (iii) modified lubricant 3, modified epoxidized rape oil; and (iv) modified lubricant 4, modified PAO. The individual modified lubricants were further modified with 0%, 0.5%, 1%, and 2% content of nano-Schiff base copper complex (nano-SBCC). A microtribometer was used to evaluate the friction coefficient between ball/flat point contacts immersed in the modified lubricants and operated in reciprocating and linear sliding mode. A comparison of the values of the friction coefficient with the lubricants further modified with nano-SBCC with those of their individual 0% nano-SBCC counterparts indicated significant decrease: (i) almost 19.18% was obtainable for the modified lubricant 1 with 2% of nano-Schiff base copper complex, (ii) almost 16.5% was obtainable for the modified lubricant 2 with 0.5% of nano-Schiff base copper complex; (iii) almost 7.42% was obtainable for the modified lubricant 3 with 1% of nano-SBCC; and (iv) almost 7.01% was obtainable for the modified lubricant 4 with 0.5% of nano-SBCC. These suggested that the addition of nano-Schiff base copper complex can efficiently decrease the friction coefficient of epoxidized or esterified microbial oil. Analyses of two-dimensional images, average profiles (across the mid-section y = 0 of the reciprocating sliding path), and three-dimensional topographies by confocal white light microscope for the worn surfaces of flats immersed in modified lubricant 1 and modified lubricant 2 suggested better wear-resistance of the modified lubricant 2 than that of the modified lubricant 1. The ability of wear resistance for the modified lubricant became better with the increasing content of nano-Schiff base copper complex from 0% to 2%. The study revealed the modification of epoxidized microbial oil + rape oil (1:1 volume ratio) and esterified microbial oil + rape oil (1:3 volume ratio) with Cu(II) chelate of bis(salicylaldehyde)ethylenediamine, reducing the magnitude of friction and wear because of their respective wear self-repairing ability. Such self-repairing ability furnishes the suitability of epoxidized microbial oil or esterified microbial oil to be effectively modified by nano-Schiff base copper complex and to substitute ordinary base oil as a mixture with rape oil.     

Nachhaltige Bausteine für die Kunststoff‐Herstellung

Plant oils are currently the principle resource for the production of bio‐based, high performance polymers, such as polyamides. This process is facilitated by giant strides in chemical catalysis and biotechnology, which allows conversion of vegetable oils in “drop‐in” chemical building blocks. These bio‐based polymer building blocks have equivalent chemical and physical properties as well as similar cost structures compared to conventional petrochemical synthesis feedstock. This allows integration of bio‐based resources into industrial production processes without significant adaptations in logistics or process configuration. However, only use of synergies between chemical and biotechnological unit operations will in future provide for sustainable and eco‐efficient process designs. To allow sustainable supply of bio‐oils to a growing chemical industry without a significant impact on food production demands development of alternative bio‐oil sourcing strategies. In this respect the development of processes for the production of microbial oils, which have equivalent chemical properties to their plant counterparts is imperative. One leading option is the biotechnological conversion of agricultural and food waste streams into microbial oils by combining enzymatic hydrolysis and fermentative production using oleaginous organisms, such as yeasts.     

Recycling of waste from polymer materials: An overview of the recent works

Polymer recycling is a way to reduce environmental problems caused by polymeric waste accumulation generated from day-to-day applications of polymer materials such packaging and construction. The recycling of polymeric waste helps to conserve natural resource because the most of polymer materials are made from oil and gas. This paper reviews the recent progress on recycling of polymeric waste form some traditional polymers and their systems (blends and composites) such as polyethylene (PE), polypropylene (PP), and polystyrene (PS), and introduces the mechanical and chemical recycling concepts. In addition, the effect of mechanical recycling on properties including the mechanical, thermal, rheological and processing properties of the recycled materials is highlighted in the present paper.     

Degradation mechanisms and environmental effects on perfluoropolyether, self-assembled monolayers, and diamondlike carbon films

The degradation mechanisms and durability of selected lubricants and environmental effects on the lubricants which could be used for microelectromechanical/nanoelectromechanical systems (MEMS/NEMS) applications were studied in this paper. The degradation of perfluoropolyether (Z-DOL), four self-assembled monolayers (SAMs)-hexadecane thiol, perfluoroalkylsilane, and alkylsilane (C8 and C18)-and diamondlike carbon (DLC) films was investigated in high vacuum. Gaseous products and friction force were detected using a quadrupole mass spectrometer and strain gauges. It is believed that triboelectrical reaction and mechanical scission cause the degradation of Z-DOL. SAMs are believed to degrade by cleavage at an interfacial bond accompanied with triboelectrical reactions. DLC is believed to degrade by mechanical shear and thermal oxidation. Environmental effects on lubricant films were studied in high vacuum, argon, and air at various humidity levels. It was found that the environment has a significant influence on the lubricant performance. The lubricant films exhibit high friction and low durability in high vacuum. Oxygen in the air can cause the thermal oxidation of SAMs and DLC films. Water molecules can act as a lubricant for Z-DOL films at a moderate humidity level, while they can penetrate the Z-DOL films at a high humidity level. Water molecules can detach the SAM molecules from the substrate, whereas, for DLC films, water molecules can act as a lubricant.     

A Review of the Effects of Olive Oil-Cooking on Phenolic Compounds

The fate of phenolic compounds in oil and food during cooking vary according to the type of cooking. From a nutritional point of view, reviews largely suggest a preference for using extra-virgin olive oil at a low temperature for a short time, except for frying and microwaving, for which there appears to be no significant advantages compared to olive oil. However, due to the poorly pertinent use of terminology, the different protocols adopted in studies aimed at the same objective, the different type and quality of oils used in experiments, and the different quality and quantity of PC present in the used oils and in the studied vegetables, the evidence available is mainly contradictory. This review tries to reanalyse the main experimental reports on the fate, accessibility and bioavailability of phenolic compounds in cooking oils and cooked vegetables, by considering different cooking techniques and types of oil and foods, and distinguishing experimental findings obtained using oil alone from those in combination with vegetables. The re-analysis indicates that incomplete and contradictory observations have been published in the last few years and suggests that further research is necessary to clarify the impact of cooking techniques on the phenolic compounds in oil and vegetables during cooking, especially when considering their nutritional properties.     

Recent development on bio-based thermosetting resins

Due to the rapid depletion of crude oil and serious environmental pollution, the synthesis of polymers from renewable resource is becoming more and more important. Up to now, a great variety of biomass and bio-based platform compounds have been taken to prepare the polymers. However, as two representative thermosetting resins, epoxy and benzoxazine resin derived from renewable feedstocks only obtain limited attention compared with the popular bio-based plastics, including PLA, PBAT and PHBV etc. The reason might be that the properties of previously reported thermosetting resins directly obtained from biomass are usually unsatisfied, and their application fields are limited. In this paper, the latest development on the synthesis of high-performance bio-based epoxy and polybenzoxazine resins are reviewed. In addition, to further broaden their applications, the functionalization strategies are also summarized. The objective of this work is to help us fully aware the present situation of bio-based thermosetting resins and then promote their faster development, especially practical application.