Method for Removal of Reactive Sulfur from Insulating Oil

Abstract

A method for removing sulfur from insulating oil. The oil is exposed to at least one sulfur scavenging material and at least one polar sorbent.

1 . A method for removing sulfur from insulating oil, the method comprising:
 exposing the oil to at least one sulfur scavenging material; and   exposing the oil to at least one polar sorbent.   
     
     
         2 . The method according to  claim 1 , further comprising:
 filtering the oil.   
     
     
         3 . The method according to  claim 1 , further comprising:
 heating the oil prior to exposing the oil to the sulfur scavenging material and exposing the oil to the polar sorbent.   
     
     
         4 . The method according to  claim 1 , wherein the at least one sulfur scavenging material is provided on a high surface area substrate. 
     
     
         5 . The method according to  claim 4 , wherein the at least one sulfur scavenging material is provided in a column. 
     
     
         6 . The method according to  claim 1 , wherein the at least one sulfur scavenging material comprises at least one of elemental copper or other sulfide forming metal or metal salts. 
     
     
         7 . The method according to  claim 6 , wherein metal salt comprises copper oxide. 
     
     
         8 . The method according  claim 6 , wherein the at least one sulfur scavenging material is provided in a shape include at least one of wire, wool, cuttings, granules, foil and sponge. 
     
     
         9 . The method according to  claim 1 , wherein the at least one sulfur scavenging material retains insoluble reaction products. 
     
     
         10 . The method according to  claim 1 , wherein the at least one polar sorbent absorbs soluble reaction products. 
     
     
         11 . The method according to  claim 10 , wherein the soluble reaction products comprise copper mercaptides. 
     
     
         12 . The method according to  claim 1 , wherein the at least one polar sorbent comprises at least one of Fullers earth and alumina. 
     
     
         13 . The method according to  claim 1 , further comprising:
 reactivating the at least one polar sorbent.   
     
     
         14 . The method according to  claim 13 , wherein the at least one polar sorbent is reactivated a plurality of times. 
     
     
         15 . The method according to  claim 1 , wherein the method is carried out at a temperature higher than an operating temperature of the oil. 
     
     
         16 . The method according to  claim 1 , wherein the method is carried out at a temperature of at least 70° C. 
     
     
         17 . The method according to  claim 1 , wherein the method is carried out in a continuous mode. 
     
     
         18 . The method according to  claim 1 , wherein the method is carried out on-line. 
     
     
         19 . The method according to  claim 1 , wherein the oil is exposed to the at least one sulfur scavenging material a plurality of times, the method further comprising:
 filtering the oil after each time that the oil is exposed to the at least one sulfur scavenging material.   
     
     
         20 . A system for removing sulfur from insulating oil, the system comprising:
 a pump operative to pump the oil through the system;   at least one sulfur scavenger containing structure; and   at least one polar sorbent containing structure.   
     
     
         21 . The system according to  claim 20 , further comprising:
 at least one filter operative to filter the oil after treatment with the at least one sulfur scavenger containing structure or the at least one sulfur sorbent containing structure.   
     
     
         22 . The system according to  claim 20 , further comprising:
 a heater operative to heat the oil prior to treatment with the at least one sulfur scavenger containing structure or the at least one sulfur sorbent containing structure.   
     
     
         23 . The system according to  claim 20 , wherein the pump is interconnected with a transformer tank. 
     
     
         24 . The system according to  claim 20 , comprising a plurality of sulfur scavenger containing structures. 
     
     
         25 . The system according to  claim 20 , wherein the oil passes through the at least one sulfur scavenger containing structure prior to passing through the at least one sulfur sorbent containing structure. 
     
     
         26 . The system according to  claim 20 , wherein the at least one sulfur scavenger containing structure and the at least one sulfur sorbent containing structure are parts of a single container.