Oxidation stability tester is suitable for evaluating the oxidation stability of the same and in-use steam turbine oil. It can also be used to evaluate the insulating oil of new mineral oil containing 2,6-di-tert-butyl-p-cresol as a rapid evaluation method for its oxidation stability. The test results are used to check the content of 2,6-di-tert-butyl-p-cresol. Tert-butyl p-cresol or 2,6-di-tert-butyl phenol or new mineral insulating oil containing both can be used for continuous performance control for each batch of oil.
Gasoline with poor oxidation stability is prone to oxidation reaction during storage and transportation, forming gums, darkening the color of gasoline, and even causing precipitation. If a viscous gel is formed in the fuel tank, filter screen, and vaporizer during use, it will affect the fuel supply in severe cases; the gel deposits on the spark plug will form carbon deposits at high temperatures and cause short circuits; deposits on the intake valve, Coking will form on the exhaust valve, causing the valve to not close tightly; deposits on the cylinder head and piston will form carbon deposits, resulting in poor heat dissipation and temperature rise of the cylinder, resulting in an increase in the compression ratio of the engine, resulting in an increased tendency to knock combustion.
It can be seen that the oxidation stability tester is very necessary, and the poor stability of gasoline will seriously affect the normal operation of the engine. So what exactly affects stability?
The fundamental reason that affects stability is its chemical composition. Alkanes, cycloalkanes and aromatic hydrocarbons in gasoline are not prone to oxidation reactions at room temperature, and various unsaturated hydrocarbons are prone to oxidation and superposition reactions, resulting in formation Colloidal. Therefore, the unsaturated hydrocarbons contained in gasoline are the main cause of unstable properties. In unsaturated hydrocarbons, due to the difference in chemical structure, the difficulty of oxidation is also different. In addition, aromatic hydrocarbons with unsaturated side chains are also easier to oxidize.
"In addition to unsaturated hydrocarbons, sulfur-containing compounds in gasoline, especially thiophenols and mercaptans, can also promote the formation of gums. The presence of nitrogen-containing compounds can also lead to the formation of gums, making gasoline become red and darker when it comes in contact with air, and even produce colloidal deposits. Straight-run gasoline fraction does not contain unsaturated hydrocarbons, so its stability is very good; while gasoline fractions generated by secondary processing (such as cracked gasoline, etc.) contain a large amount of unsaturated hydrocarbons and other non-hydrocarbon compounds, their stability is poor .