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Commercial Developments
Published in Leslie R. Rudnick, Synthetics, Mineral Oils, and Bio-Based Lubricants, 2020
There is a move toward synthetic formulations, particularly PAO/ester, ester, and PAG-based oils. The synthetic oils offer longer life and so reduce the need for oil changes. PAOs provide excellent viscosity index and low pour point. These properties make them a fluid of choice for applications characterized by wide ranges of operating temperatures. The possible hydrolytic instability of esters has made the selection of PAO/ester blends and ester-based oils a critical issue. PAGs offer improved resistance to micropitting but have compatibility problems with coatings and seal material. As a result, new oil compatibility specifications for paints, lacquers, sealants, and bearing materials have been included in the latest specifications. New extended lifecycle seal tests for both static and dynamic seals have also been introduced. The SKF Emcor rust test is being evaluated to include testing with salt water.
Lubrication of Mechanical Components in Wind Turbines
Published in Bella H. Chudnovsky, Lubrication of Electrical and Mechanical Components in Electric Power Equipment, 2019
Mineral oils cannot meet the basic demands for use in wind turbine gearboxes. Synthetic oils are preferable since they offer wide range of benefits, including improved thermal resistance, better viscosity characteristics, product longevity, and longer machine component life. To formulate gear oils, different base oils such as polyalphaolefin (PAO), polyglycol, or rapidly biodegradable ester are used. PAOs provide excellent viscosity index and low pour point. These properties make them a fluid of choice for applications characterized by wide ranges of operating temperatures. There have been hydrolysis issues (breakdown in the presence of water) with PAO/ester blends, making selection of hydrolytically stable products a critical issue. PAGs (polyalkalene glycol) offer improved resistance to micropitting but have compatibility problems with coatings and seal material [23].
Production of Biolubricant Basestocks from Structurally Modified Plant Seed Oils and Their Derivatives
Published in Sonil Nanda, Prakash Kumar Sarangi, Dai-Viet N. Vo, Fuel Processing and Energy Utilization, 2019
Venu Babu Borugadda, Vaibhav V. Goud, Ajay K. Dalai
Mineral oils originate from crude oil, which contains many hydrocarbon molecules and traces of nitrogen, sulfur, oxygen, and metal salts. Synthetic oil is a blend of chemicals that are artificially made by a chemical modification of petroleum-derived products. They are more highly stable at high temperatures and oxidation atmospheres than many conventional lubricants. Conversely, synthetic and mineral oils contain harmful substances that pollute the natural ecosystem and are difficult to dispose of. According to Gawrilow (2004), annually, 10-15 MT of petroleum-based fuels and lubricants enter the ecosystem through accidental spills, total loss, and evaporation. The presence of these mineral-based lubricants in the environment pollutes the atmosphere, land, and groundwater posing many adverse risks to the health of humans, plants, and aquatic life. On the other hand, conventional oils are expensive, deplete at a faster rate, and are toxic to the environment because of their non-biodegradable nature. Therefore, due to these environmental threats, the mineral-based synthetic lubricants usually are not considered eco-friendly.
Friction and wear characteristics of vegetable oils using nanoparticles for sustainable lubrication
Published in Tribology - Materials, Surfaces & Interfaces, 2018
Wani Khalid Shafi, Ankush Raina, Mir Irfan Ul Haq
These are the substitutes for the petroleum-based oils and are made in order to overcome the limitations of mineral oils. Synthetic oils are artificially made with uniform hydrocarbon molecules. This gives them the property to work in extremely low and high temperatures. Synthetic oils are made from chemically modified petroleum products instead of using the complete crude oil.
An overall review on the tribological, thermal and rheological properties of nanolubricants
Published in Tribology - Materials, Surfaces & Interfaces, 2021
Wani Khalid Shafi, M. S. Charoo
The enormous cost of tribological deficiencies is mostly caused by the large amount of energy and material losses occurring in every mechanical system at operational stage. It was estimated that by the application of the basic principles of tribology, the economy of U.K could save approximately £515 million per annum at 1965 values [1]. A similar report published in West Germany in 1976 revealed that the economic losses caused by friction and wear cost about 10 billion DM per annum, at 1975 values, which is equivalent to 1% of the Gross National Product. Energy conservation has obliged the researchers to look for alternative sustainable solutions inciting the emergence of nanolubrication. Nanolubrication involves the dispersion of nanoparticles in lubricating oils. Nanoparticles of size less than 100 nm possess excellent optical mechanical and electrical properties resulting in the improvement of tribological and thermo-physical properties of base oils. Main constituents of nanolubrication system include base oil, additives and surfactants. The liquid lubricants are classified into following types: minerals oils, synthetic oils, vegetable oils and animal fats [2]. The most commonly used liquid lubricant in automobiles is mineral oil. Mineral oil is composed of carbon and hydrogen in 83–87% and 11–14% respectively [2]. Mineral oils are classified into paraffinic, napthenic and aromatic. Paraffins are most suited for lubrication owing to their good pour point, high flash point, high viscosity index and better oxidation stability. Synthetic oils are man-made lubricants for enduring harsh lubrication conditions. Some of the common types of synthetic oils are polyglycols, ethers, perfluoropolyalkylether and perflouropolyethers. Synthetic oils possess better oxidation stability and viscosity index as compared to mineral oil owing to their uniform shaped carbon–hydrogen molecules [3]. Vegetable oils are emerging potential candidates as lubricants. Vegetable oils are combination of triglycerides made of glycerol molecules with three fatty acids attached by means of ester linkages. The classification of vegetable oils is based on the type of fatty acids present in them. These are classified into lauric (e.g. coconut oil), oleic (e.g. olive oil, hazelnut oil, avocado oil), linoleic (e.g. cottonseed oil), erucic (e.g. mustard oil) and ricinoleic oils (e.g. castor oil) [3]. Vegetable oils exhibit high viscosity, viscosity index, flash point and fire points [3]. Additives are added to the base oil that improve some properties of, or provide new property to the base oil. Combination of different additives and their quantities are determined by the lubricant type (engine oils, gear oils, hydraulic oils, etc.) and the specific operating conditions (temperature, loads, machine parts materials, and environment). The additives used for the better effectiveness of nanolubricants are shown in Table 1 [4–9].