M Ghazimisaeid - Rude Shur Power Plant , Siemens SSK- E F / Rudeshur SCPP, Tehran, Iran
K Moshtaghi Monem - KSPK Company
M Movaagr - Rude Shur Power Plant , Siemens SSK- E F / Rudeshur SCPP, Tehran, Iran
A Ayobe - KSPK Company
P Yadegary - KSPK Company

Some sulphur compounds, for example dibenzyldisulphide (DBDS), may result in the deposition of copper sulphide (Cu۲S) in paper insulation, reducing its electrical insulationproperties This has resulted in several equipment failures in service,so it is urgent to reduce or eliminate corrosive sulfure from the oil. In this study auxilary transformer of Rudshur power plant (siemens) which were initially filled with oil containing DBDS as an addtive were desulforization with a modern desulfurization system made by KSPK company(ODS-۶۰) that filled with novel modified catalyst , This project was carried out under the supervision of the chemical unit of the RUD power plant and the technical cooperation between the power plant and KSPK company.the oil type was ۱۰GBN and the oil volume of desulfurization and oil physical and chemical regeneration was ۷۰۰۰ liters.Preperation of catalyes in ۶ working dayes and of desulfurization and physical and chemical treatmented were done in ۸ working dayes. In order to decrease DBDS from ۱۶۰ppm and corrosive to N.D(≤۵ ppm) and non corrosive,۵ passes were applied out of transformer(external tank),another pass was considered for treatment of entrapped DBDS in active part. At the end of treatment, DBPC antioxidant was added with a concentration of ۰.۳%.Final results according to Duetchland and also Niroo Reasch laboratory approved noncorosive oil lower than ۱۰ppm DBDS in transformer.the amount of economic cost saving compare oil change was ۷۰% as well as treated oil cost was ۳۰% versus oil change cost. This project was carried out with the financial support of the management of Mahtab Gostar Company.

Corrosive Sulfur, Di-Benzyl Di-Sulfide (DBDS), Desulfurization, Oil Regeneration, novel modified catalyst