Corrosion Effect of Naphtha Solutions of Sulfur and Sulfur Compounds'

Corrosion Effect of Naphtha Solutions of Sulfur and. Sulfur Compounds'. By A. E. Wood, Clyde Sheely, and A. W. Trusty. MISSISSIPPI COLLEGE, CLINTON, M...
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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.

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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