Could anyone provide information and technical details on diesel anti-wear agents?
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As the requirements for diesel sulfur content become increasingly stringent, with National VI standards specifying a sulfur content of less than or equal to 10 ppm, it has become difficult to meet these requirements solely through physical and simple chemical refining methods. The most effective method is deep hydrogenation of diesel. However, as the degree of diesel hydrogenation increases and the sulfur content decreases, the lubricity of the diesel itself is also depleted; moreover, some of the high-molecular-weight polar molecular structures present in the diesel are destroyed, including those molecules that provide antioxidant and anti-wear properties. As a result, the pump head of the engine’s diesel injector wears out more rapidly during use, which in turn leads to vehicle failures. The automotive diesel standard GB19147 specifies requirements for the lubricity of diesel, stipulating that the corrected wear mark diameter at 60°C should not exceed 460 micrometers. As a result, to meet the requirements regarding diesel sulfur content, deep hydrodesulfurization is necessary; however, this also causes the lubricity parameters of the diesel to become unsatisfactory in terms of wear mark diameter. To address this issue, it is necessary to add certain polar macromolecular substances with anti-wear properties to the diesel, so as to form a protective film at the contact surfaces and reduce wear on the fuel injection pump. This is diesel anti-wear agent, but there is very little information available online about it. I wonder if anyone here has such information and could provide a comprehensive overview. 1. Diesel anti-wear agents mainly refer to which type of organic substances or combinations of several organic substances. 2. Production process technology for major diesel anti-wear agents.
Technical Instruction Manual for Diesel Ester Anti-wear Agents I. Product Name: Diesel Ester Anti-wear Agents II. Product Advantages: Diesel ester anti-wear agents represent the most advanced, environmentally friendly, and sustainable type of diesel anti-wear additive available today. Compared with similar products, it features a high molecular weight (1200–1400) and long molecular chain length, giving it advantages such as strong hydrolysis resistance, good detergency and dispersion properties, high extreme pressure performance, and excellent lubricating properties. Its template lubricating film effect has even surpassed that of similar American products; the amount required is one-third of that of fatty acids with low freezing points, with a recommended dosage of 1‰ (the optimal addition ratio can be determined through specific tests). III. Development Mechanism: In recent years, as global fuel standards have become increasingly stringent and new environmental protection regulations have been introduced, the demands on environmental protection have grown ever higher. Similarly, higher requirements have been placed on the quality of diesel, which is used as a fuel for vehicles. As a result, new specifications have been introduced regarding the nitrogen and sulfur content in diesel products, while stricter requirements have also been set for parameters such as cetane number, cold flow properties, aromatic content, 90% or 95% distillation temperature (T90 or T95), and density. Diesel that has undergone hydrorefining can have sulfur and aromatics removed, but it also loses the natural components in diesel that provide anti-wear properties; as a result, the lubricating properties of the diesel are reduced and friction between metals increases. Statistics show that about one-third of energy consumption is tied to friction, and over two-thirds of component failures are caused by wear and tear. Therefore, improving lubrication performance to reduce friction and wear and prevent scorching is of great significance to the national economy. IV. Mechanism of action of diesel anti-wear agents: The poor anti-wear properties of diesel are due to the high temperatures generated during the friction between low-viscosity, light fuel and metals, which leads to the breakdown of the lubrication film and subsequent wear, scuffing, corrosion, and other issues. In terms of the lubricating properties of diesel, polycyclic aromatic hydrocarbons, nitrides, and oxides play a key role in providing lubrication. In fact, sulfides in diesel promote wear; they often occur alongside nitrogenous and oxygen-containing compounds as well as polycyclic aromatic hydrocarbon components that serve as anti-wear agents. Hydroprocessing of diesel removes these sulfides, but it also eliminates the aforementioned anti-wear components, resulting in a **reduction in the lubricity of the diesel**. The main function of anti-wear agents is to prevent scratches, seizing, wear, and other such issues. Its solubility in diesel relies primarily on physical and chemical adsorption forces, which form a strong, oriented adsorption film on the friction surface to provide lubrication. For effective lubrication through adsorption, it is not only necessary for the molecules to be polar, but also for their structure to facilitate the formation of a protective film with high resistance; therefore, only long-chain linear molecules containing polar groups (such as oxygen- and nitrogen-containing groups) can meet these requirements. The wear resistance of hydrogenated diesel can only be improved through the following methods: one is to modify the diesel blending formula by adding a small amount of diesel components with good lubricity. The second is the method of adding anti-wear additives or blending components to diesel. Third is to change the manufacturing process operations. V. Types of diesel anti-wear agents: Diesel anti-wear agents are additives that improve the lubricating properties of diesel. The main components of ideal anti-wear additives are polar, long-chain linear molecules containing oxygen and nitrogen. Currently, the additives that can improve the lubricating properties of diesel include long-chain carboxylic acids, esters, amides, ethers, alcohols, and other similar compounds. Their characteristic is that they are oily agents containing polar groups such as hydroxyl groups, amine groups, and organic carboxyl groups. The mechanism of such anti-wear agents lies in the adsorption of nitrogen- or oxygen-containing substances on the metal surface, resulting in the formation of dense monoesters. Esters represent a class of components for clean diesel that have shown great potential for further development in current research both domestically and internationally. Esters are formed by the catalytic dehydration of organic acids and alcohols. Its advantages include strong hydrolysis resistance, good cleaning and dispersion properties, and high extreme pressure performance. Ester-based products contain various forms of oxygen atoms, such as those in carbonyl groups and alcohol groups, which enable the formation of a thick oil film between friction surfaces. This is crucial for lubrication, as it effectively protects metal surfaces from oxidation and corrosion. It is non-toxic and harmless, making it an environment-friendly anti-wear additive for hydrogenated diesel. VI. Introduction to our company’s products: Taking advantage of our own capabilities and considering the current state of development in diesel anti-wear agents, our company has developed new ester-based diesel anti-wear agents. It features strong water resistance, good cleaning and dispersing properties, high extrudability, excellent lubricity, and a low HLB value. Break the monopoly of similar foreign products. It is epoch-making. For fatty acid esters with different carbon chain lengths, the longer the carbon chain length of the fatty acid ester, the better its anti-wear effect. Mixing various fatty acid esters into diesel yields a better anti-wear effect. Its addition amount is one-third of that of low-freezing-point fatty acids, at 1‰; the longer the carbon chain of the ester, the better the lubricating effect of the resulting ester. Therefore, it is extremely important to develop ester-based diesel anti-wear agents. VII. Outlook: Environmental issues have become a global problem, and people’s demands for environmental quality are increasing. Developing new environmentally friendly fuel additives is an important step toward sustainable development. From a development trend perspective, new environmentally friendly additives are moving towards lower sulfur and lower aromatic content. Diesel additives should possess excellent anti-friction properties, effectively improving the lubricity of low-sulfur diesel, as well as its cleanliness and flowability at low temperatures. At present, the **standard requirement for sulfur content in diesel fuel used in China is less than 500 μg/g. To ensure that hydrogenated diesel in China does not cause problems such as clogging of filters during use, many scholars have studied various fatty acids and fatty acid esters as diesel anti-wear agents. In particular, diesel anti-wear agents containing boron, nitrogen, and oxygen groups have little impact on other properties of diesel; a small amount of these agents is sufficient to effectively reduce friction and wear on metals. It is reported that many scholars abroad have studied long-chain fatty acid ester compounds, finding that they possess good anti-wear properties without affecting other physical and chemical characteristics of diesel. Such anti-wear agents will become key targets for development in our country in the future. To keep up with international standards, our company has developed high-efficiency diesel anti-wear agents and high-performance, multi-functional diesel additives, which enhance performance and increase efficiency while helping to save fuel and reduce emissions
Thank you for your reply. You mentioned that the sulfur content in diesel is 500PPM; the current standard is supposed to be 10ppm. With a sulfur content of 500PPM, it shouldn’t be necessary to use anti-wear agents, right? Do you have the specific names of the ester compounds there?
I have two suggestions for you: first, use oleic acid as an anti-wear agent. II. The essential function of an anti-wear agent is to form a film; corrosion inhibitors and similar substances can be considered for this purpose