A methodological review on bio-lubricants from vegetable oil based resources
TL;DR: In this paper, a review of the available literature and recently published data related to development of bio-lubricants by chemical modifications of vegetable oils is presented, where the authors focus on lubricating oils as well as lubricating greases developed from vegetable oil.
Abstract: Finiteness of global crude oil reserve, rising crude oil prices, and issues related to environment seems to be a reality check for the problems of emerging generations. Present article focuses on lubricating oils as well as lubricating greases developed from vegetable oil. Vegetable oil based lubricants are an attractive alternative to conventional petro based lubricants due to number of their physical properties including renewability, biodegradability, high lubricity and high flash points. Still they have not yet replaced petro based lubricants due to their inappropriate chemical structure, which lags them behind at various odd conditions during applications. The challenges in this field are to improve certain characteristics of vegetable oils without impairing their excellent tribological and environmentally relevant properties. Chemical modification of vegetable oils overcomes the structural problems related to vegetable oils which in turn makes them fit for the application of lubricant. In this review article, we have reviewed the available literature and recently published data related to development of bio-lubricants by chemical modifications of vegetable oils.
Citations
More filters
TL;DR: In this paper, a detailed treatment on bio-based lubricants, the various vegetable oils used as the feedstocks for the production of bio-baking, physicochemical properties, processes used for chemical modification of vegetable oils, the lubrication properties of biobased oils, as well as the various additives used to improve the properties of these oils are discussed.
Abstract: The possible scarcity of oil and gas resources in the future (whether in quantity or areas of availability) is a major concern throughout the world. For this reason, governments all over the world are working on reducing their dependence on imported energy resources. Alternative energy resources such as bioethanol, biodiesel and biomass have gained prominence over the years in order to substitute petroleum-derived products. Bio-based lubricants have also gained importance as alternatives to conventional petroleum-based lubricants in various applications, especially the automotive industry. Despite the benefits of bio-based lubricants, these lubricants are still far from being practical substitutes. Since bio-based lubricants are typically produced from raw vegetable oils, these lubricants have poor cold flow properties as well as low thermo-oxidation and hydrolytic stability. However, these shortcomings can be addressed by modifying the vegetable oils chemically or incorporating additives into the oils. This review provides a detailed treatment on bio-based lubricants, the various vegetable oils used as the feedstocks for the production of bio-based lubricants, the physicochemical properties of bio-based lubricants, the processes used for chemical modification of vegetable oils, the lubrication properties of bio-based lubricants, as well as the various additives used to improve the properties of bio-based lubricants. It is believed that this review paper will provide useful insight to researchers and practioners in the field regarding bio-based lubricants.
213 citations
TL;DR: In this article, the potential use of non-edible vegetable oil for the production of bio-lubricants is discussed, and resources, properties, benefits, and application of NDO-based bio lubricants as alternatives are discussed.
123 citations
TL;DR: In this article, a review of the tribological performance of various types of biolubricant base stocks and their related additives is presented, based both on the tabulation of the friction coefficient and on the measurement of wear scar from experimental studies.
Abstract: Biolubricants are gaining popularity and acceptance globally due to their sustainable and environmentally friendly properties; being derived from feedstocks from vegetable oils. Indeed, the potential for biolubricants to eventually replace conventional lubricants is currently viewed in the literature as a real possibility. This study will provide valuable information pertaining to the formulation of biolubricants, by assessing and evidencing the tribological performances of various types of biolubricant base stocks and their related additives. This study begins with a presentation of the basic tribological parameters in lubrication. Following that, the criteria for the molecular structure of biolubricant base stocks for high tribological performance are discussed, based both on the tabulation of the friction coefficient and on the measurement of wear scar from experimental studies. The biolubricant base stocks under review in this study include vegetable oils (VO), epoxidized VO, ring-opened products from epoxidized VO, estolides, and polyol esters. This review also discusses recent advances in eco-friendly tribological additives such as plant-derived compounds and polymers, particulate and layered materials, and ionic liquids. The performance and various applications of these additives are also reviewed.
118 citations
TL;DR: In this article, issues related to AMMC fabrication, corrosion resistance, wear resistance, machining parameter optimization, and chip analysis of AMMCs are discussed. And the authors provide a guideline to researchers about present scenario of AM MC fabrication using stir casting process.
Abstract: Aluminum metal matrix composites (AMMCs) used in different industries from automotive to aerospace for specific purposes. Many problems hinder the full-scale industrialization of AMMCs but the main problems include wettability, particle distribution, porosity, and chemical reaction. These problems have explicit effects on mechanical, wear, and corrosion resistance properties of the composite materials. Therefore, it is essential to cope up with these problems for better quality of AMMCs. This paper focuses on issues related to AMMCs fabrication, corrosion resistance, wear resistance, machining parameter optimization, and chip analysis of AMMCs. Literature provides a guideline to researchers about present scenario of AMMC fabrication using stir casting process. Moreover, paper presents properties and applications of AMMCs.
108 citations
TL;DR: The immobilized lipase (34MDP-PP) showed conversions of 99% for NPG and 92% for TMP, after 24 h of reaction, maintaining the results obtained with the free enzyme, and could be reused for six consecutive reaction cycles without a reduction in the final conversion.
106 citations
References
More filters
TL;DR: In this paper, the authors showed that the conversion to methyl, ethyl and butyl esters from cottonseed, peanut, soybean and sunflower oils can be done in 1 hr with an alkaline catalyst.
Abstract: Transesterification reaction variables that affect yield and purity of the product esters from cottonseed, peanut, soybean and sunflower oils include molar ratio of alcohol to vegetable oil, type of catalyst (alkaline vs acidic), temperature and degree of refinement of the vegetable oil. With alkaline catalysts (either sodium hydroxide or methoxide), temperatures of 60 C or higher, molar ratios of at least 6 to 1 and with fully refined oils, conversion to methyl, ethyl and butyl esters was essentially complete in 1 hr. At moderate temperatures (32 C), vegetable oils were 99% transesterified in ca. 4 hr with an alkaline catalyst. Transesterification by acid catalysis was much slower than by alkali catalysis. Although the crude oils could be transesterified, ester yields were reduced because of gums and extraneous material present in the crude oils.
1,990 citations
TL;DR: In this article, the transesterification of vegetable oils with methanol as well as the main uses of the fatty acid methyl esters are reviewed. But, the anchored catalysts show leaching problems.
Abstract: The transesterification of vegetable oils with methanol as well as the main uses of the fatty acid methyl esters are reviewed. The general aspects of this process and the applicability of different types of catalysts (acids, alkaline metal hydroxides, alkoxides and carbonates, enzymes and non-ionic bases, such as amines, amidines, guanidines and triamino(imino)phosphoranes) are described. Special attention is given to guanidines, which can be easily heterogenized on organic polymers. However, the anchored catalysts show leaching problems. New strategies to obtain non-leaching guanidine-containing catalysts are proposed. Finally, several applications of fatty acid esters, obtained by transesterification of vegetable oils, are described.
1,293 citations
TL;DR: In this article, the effects of the type of alcohol, 1-butanol or methanol (MeOH), molar ratio of alcohol to SBO, type and amount of catalyst, and reaction temperature on rate constants and kinetic order were examined.
Abstract: Transesterification of soybean oil (SBO) and other triglycerides with alcohols, in the presence of a catalyst, yields fatty esters and glycerol. Di- and monoglycerides are intermediates. Reactions are consecutive and reversible. Rate constants have been determined for each reaction with a computerized kinetic program. The effects of the type of alcohol, 1-butanol or methanol (MeOH); molar ratio of alcohol to SBO; type and amount of catalyst; and reaction temperature on rate constants and kinetic order were examined. Forward reactions appear to be pseudo-first order or second order depending upon conditions used. Reverse reactions appear to be second order. At a molar ratio of MeOH/SBO of 6:1, a shunt reaction was observed. Energy of activation was determined for all forward and reverse reactions under a variety of experimental conditions from plots of log k vs 1/T. Values ranged from 8–20 kcal/mol.
1,215 citations
TL;DR: A comprehensive review of the effect of various seaweed species and seaweed products on plant growth and development with an emphasis on the use of this renewable bioresource in sustainable agricultural systems is provided.
Abstract: Marine algal seaweed species are often regarded as an underutilized bioresource, many have been used as a source of food, industrial raw materials, and in therapeutic and botanical applications for centuries. Moreover, seaweed and seaweed-derived products have been widely used as amendments in crop production systems due to the presence of a number of plant growth-stimulating compounds. However, the biostimulatory potential of many of these products has not been fully exploited due to the lack of scientific data on growth factors present in seaweeds and their mode of action in affecting plant growth. This article provides a comprehensive review of the effect of various seaweed species and seaweed products on plant growth and development with an emphasis on the use of this renewable bioresource in sustainable agricultural systems.
1,130 citations
01 Jan 2007
TL;DR: A number of pretreatment technologies are under development and being tested in pilot scale for lignocellulose, which is the largest known renewable carbohydrate source as mentioned in this paper, but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modifi cation of the lignosic structure.
Abstract: The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose and hemicelluloses but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modifi cation of the lignocellulosic structure. A number of pretreatment technologies are under development and being tested in pilot scale. Hydrolysis of lignocellulose carbohydrates into fermentable sugars requires a number of different cellulases and hemicellulases. The hydrolysis of cellulose is a sequential breakdown of the linear glucose chains, whereas hemicellulases must be capable of hydrolysing branched chains containing different sugars and functional groups. The technology for pretreatment and hydrolysis has been developed to an extent that is close to a commercially viable level. It has become possible to process lignocellulose at high substrate levels and the enzyme performance has been improved. Also the cost of enzymes has been reduced. Still a number of technical and scientifi c issues within pretreatment and hydrolysis remain to be solved. However, signifi cant improvements in yield and cost reductions are expected, thus making large-scale fermentation of lignocellulosic substrates possible. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd
957 citations