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I N D U S T R I A L A N D ENGINEERING CHEMISTRY
Vol. 17,No. 8
Corrosion Effect of Naphtha Solutions of Sulfur and Sulfur Compounds' By A. E. Wood, Clyde Sheely, and A. W. Trusty MISSISSIPPICOLLEGE, CLINTON, MIS.
P
RACTICALLY all known petroleum oils contain Metals and alloys employed were t h e usual grade obtained sulfur in amountsvarying from a few hundredths of a from the laboratory supply houses and were used as delivered. per cent to more than 4 per cent. Free sulfur, hydroExperimental Methods gen sulfide, alkyl sulfides, mercaptans, thiophenes, thiophanes and carbon disulfide have been reported in certain Detroleum ( a ) Three-Hour Test af 50' C. Clean Dolished strim of alumindistillates and residues. When a petroleum distillate contain- ium,' zinc, steel, copper, brass, and silver were plaied in clean tubes along with 10 CC. Of the naphtha stock SOlUtiOn to be ing mercaptansis refined by either the hypoch~oriteor " &+ unknown solution. I n no instance was the error more than i &$+$ &j $$ ti< .;i j 'b B > i I B d i B i 8 i B i 0.01 per cent. I n carrying out this test, 10 cc. of each naphtha solution and a clean polished strip of copper were placed in a 2 50 $$ clean test tube. The solution of hvdrogen sulfide is the only .-i 'gz %.j $ naphtha solution of a sulfur compound-thus far studied t h i t E $ VlUG 1 -32 - 2e 2i. - 4...z. . 2% g i y$ has an effect on the copper strip similar to the free sulfur 0 5 ;sVl;cg 7 :-z $7, - . d E ' 5 A c"% d l i 62 5 6 ;j 3 fi i solution. Since hydrogen sulfide can be readily removed -: - = > 1; 2 Z m & $ : i 3 $ z & ; & ;i ; i ii QE *. from a naphtha without in any way affecting the free sulfur content, this method should find application where a fairly .-Y e.*) accurate estimation of the free sulfur content is desired. v, C 3 rla iI Where the free sulfur content of the unknown is less than 0.03 . . u j $ z 7 : &n u u , , . . . ;i % per cent, it is best t o place the test tubes in a thermostat a t a '1 G j .> E 2 z i'j, & ; i&. ~i ti>' temperature well below the boiling point of the naphtha. : & : i g i $$$ i ;i 2 5 ;$ g i B * ;g g; Heat greatly increases the rapidity of the reaction. oe) .-._ Naphtha solutions of the other sulfur compounds studied . ax a ... o r= i 2 a.Vl c v were only mildly corrosive in a few instances. Where heat -- -. -:, d 1U0L:. * sea a . . . . . i i was employed, as in Experiments (a) and ( c ) , the alkyl diI- % > . $ j $ j E E a b $ $Pl'du'j, M;i & ; w; $, sulfide tarnished the copper and silver strips. This may have x 2 ;* ;< p ; 5 G i s ig.%:i $&Z ;i ;i ;$ 3 s ;i been caused by the decomposition of the disulfide. In the 30-day test a t room temperature, naphtha solutions of all the .& ai . . . . sulfur compounds studied, except the alkyl sulfide and sul. . Y e ) j X -'x 'jy' a 4ya jj - ... 2E p-2zzz -i 5c . j "EXa "E g a gg fone, tarnished the silver strip. The disulfurized naphtha E a 2? a? f $ +& affected the mercury slightly, so that it was impossible to ;? 5 % , . 2 v;e z e * r L .E~! - n ~$ , b e .$E ,@ f! -.-_ . -- . .E e M-. . E E 50-, . E M-, , g tell to what extent the mildly corrosive sulfur compounds MtlHowever, it is probably true that m E m. ;ic i 8 ii8 ii E' ii 8 ii;ii8 ii8 ii affected the mercury. Z4- -. 2 i iIii
