Antiwear Additives

Antiwear Additives. Fuel system parts wear down with time, so antiwear additives are mixed into diesel fuel.

Originally, diesel fuel has certain anti-wear properties due to the presence of naphthenic hydrocarbons. Many sulfuric compounds in diesel fuel also have such properties (benzothiophenes and sulfides). However, environmental considerations dictate limitations of sulfur content, making it impossible to ensure the required degree of wear protection by sulfur only. Special additives are required.

The most common element of such additives is carboxylic acid. These are usually fatty acids of tall oil and their fractions, which are obtained from wood. However, the acid contains resinous acids, which degrade stability and performance of diesel. Beside the fatty acids, additives also contain corrosion inhibitor and a demulsifier. Alkyl salicylic acids are also quite efficient.

Antiwear additives create a layer on the surface of metal, distributing the loads more evenly and thus reducing the possible wear. The layer contains products of mechanical and chemical transformation of the additive. The lubricity of the additives is due to adsorption on the metal surface as well as chemical activity of the additive to the material of the friction parts.

Additives by BASF, Clariant, Lubrizol are based on tall oil acids with various supplementary components, additives by Infinеum are based on complex esters of mono and diglycerol and fatty acids with С12-С18 chains.

обновлено: February 13, 2017 автором: dannik