Given that various refining processes that are common today for the production of base oils can lead to the production of base oils with different properties, the American Petroleum Association (API) has classified base oils according to their physicochemical properties and characteristics. You can see this classification in the table at the bottom of the page. The first three groups are the base oils obtained from crude oil refining, among which group III base oils are the group that has been processed the most, is the most expensive and has the highest yield among the mineral oils obtained from crude oil. Has. Group IV oils are synthetic (PAO based) and are made chemically. Esters, glycols and other base oils that do not meet the specifications of the first four groups are in group V of this classification. Petroleum oils, which have a low index due to the low percentage of paraffin in their composition, are also included in this group. Naphthenic base oils are produced from crude oils that do not contain paraffin and have a high percentage of naphthenic materials (saturated rings). Only a few oil fields in the world can extract crude oil. Almost all oil fields in the Middle East are paraffinic in nature, so the base oil from their refining is also paraffinic. Due to the lack of wax (paraffinic materials), naphthenic base oils have very low pour points and for this reason, they are used in the formulation of oils for refrigeration systems. They are very close to Group IV synthetic oils, and lubricant manufacturers can use the word “synthetic” on products made with these base oils. All base oils currently produced in Iran are refined by solvent extraction and the resulting base oils are included in Group I of the API classification. No unit has yet been set up to produce Group II and above base oils in Iran, and lubricant manufacturers meet their needs for these base oils through imports. Click Tom to see the oil page.
