Hydrogen sulfide scavengers and methods for removing hydrogen sulfide from asphalt

Abstract

A method for reducing hydrogen sulfide in asphalt includes adding a hydrogen scavenger composition to the asphalt. The hydrogen sulfide scavenger includes a polyaliphatic amine having the formula I: H 2 NRNH—(RNH) n —H  I R is an aliphatic radical and n is from about 0 to about 15. A method for treating asphalt and a hydrogen sulfide scavenger are also provided.

1 . A method for reducing hydrogen sulfide in asphalt, comprising adding a hydrogen sulfide scavenger composition to the asphalt, wherein the hydrogen sulfide scavenger comprises a polyaliphatic amine having formula I:
   H 2 NRNH—(RNH) n —H  I   
     wherein R is an aliphatic radical and n is from about 0 to about 15. 
   
   
       2 . The method of  claim 1 , wherein the aliphatic radical is a C 1 -C 30  alkyl, C 2 -C 30  alkenyl or C 1 -C 30  alkoxy. 
   
   
       3 . The method of  claim 1 , wherein the polyaliphatic amine is a polyalkyleneamine. 
   
   
       4 . The method of  claim 3 , wherein the polyalkyleneamine is selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, propylethylenediamine, tetrabutylenepentamine, hexaethyleneheptamine, hexapentyleneheptamine, heptaethyleneoctamine, octaethylenenonamine, nonaethylenedecamine, decaethyleneundecamine, decahexyleneundecamine, undecaethylenedodecamine, dodecaethylenetridecamine, tridecaethylenedodecamine, dodecaethylenetriamine, tridecaethylenetetradecamine and N-tallow propylenediamine. 
   
   
       5 . The method of  claim 1 , wherein the scavenger composition is added in an amount of from about 50 ppm to about 3000 ppm by weight, based on the weight of the asphalt. 
   
   
       6 . The method of  claim 1 , wherein the hydrogen sulfide scavenger composition further comprises a solvent. 
   
   
       7 . The method of  claim 1 , wherein the hydrogen sulfide scavenger composition further comprises a catalyst. 
   
   
       8 . The method of  claim 7 , wherein the catalyst has formula II:
   R 1 R 2 R 3 R 4 N + X −   II   
     wherein R 1 , R 2 , R 3  and R 4  are each independently alkyl groups having from 1 to 20 carbon atoms, hydroxyalkyl groups having from 1 to 20 carbon atoms or an aryl group having from 6 to 20 carbon atoms; and X is a halide or methyl sulfate. 
   
   
       9 . The method of  claim 8 , wherein the catalyst is selected from the group consisting of dicocodimethylammonium chloride, ditallowedimethylammonium chloride, di(hydrogenated tallow alkyl) dimethyl quaternary ammonium methyl chloride, methyl bis(2-hydroxyethyl cocoalkyl quaternary ammonium chloride, dimethyl(2-ethyl) tallow ammonium methyl sulfate and hydrogenated tallow alkyl (2-ethylhyexyl) dimethyl quaternary ammonium methylsulfate. 
   
   
       10 . The method of  claim 7 , wherein the scavenger composition comprises from about 20 to about 98 percent by weight polyaliphatic amine, from about 2 to about 20 percent by weight catalyst and from 0 to about 78 percent by weight of a solvent, based on the weight of the composition. 
   
   
       11 . A method for treating asphalt comprising adding a hydrogen sulfide scavenger composition to the asphalt products, wherein the hydrogen sulfide scavenger composition comprises a polyaliphatic amine having the formula I:
   H 2 NRNH—(RNH) n —H  I   
     wherein R is an aliphatic radical and n is from about 0 to about 15. 
   
   
       12 . The method of  claim 11 , wherein the aliphatic radical is a C 1 -C 30  alkyl, C 2 -C 30  alkenyl or C 1 -C 30  alkoxy. 
   
   
       13 . The method of  claim 11 , wherein the polyaliphatic amine is a polyalkyleneamine. 
   
   
       14 . The method of  claim 13 , wherein the polyalkyleneamine is selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, propylethylenediamine, tetrabutylenepentamine, hexaethyleneheptamine, hexapentyleneheptamine, heptaethyleneoctamine, octaethylenenonamine, nonaethylenedecamine, decaethyleneundecamine, decahexyleneundecamine, undecaethylenedodecamine, dodecaethylenetridecamine, tridecaethylenedodecamine, dodecaethylenetriamine, tridecaethylenetetradecamine and N-tallow propylenediamine. 
   
   
       15 . The method of  claim 11 , wherein the scavenger composition is added in an amount of from about 50 ppm to about 3000 ppm by weight, based on the weight of the asphalt. 
   
   
       16 . The method of  claim 11 , wherein the hydrogen sulfide scavenger composition further comprises a solvent. 
   
   
       17 . The method of  claim 11 , wherein the hydrogen sulfide scavenger composition further comprises a catalyst. 
   
   
       18 . The method of  claim 17 , wherein the catalyst has formula II:
   R 1 R 2 R 3 R 4 N + X −   II   
     wherein R 1 , R 2 , R 3  and R 4  are each independently alkyl groups having from 1 to 30 carbon atoms, hydroxyalkyl groups having from 1 to 30 carbon atoms or an aryl group having from 6 to 30 carbon atoms; and X is a halide or methyl sulfate. 
   
   
       19 . The method of  claim 18 , wherein the catalyst is selected from the group consisting of dicocodimethylammonium chloride, ditallowedimethylammonium chloride, di(hydrogenated tallow alkyl) dimethyl quaternary ammonium methyl chloride, methyl bis(2-hydroxyethyl cocoalkyl quaternary ammonium chloride, dimethyl(2-ethyl) tallow ammonium methyl sulfate and hydrogenated tallow alkyl (2-ethylhyexyl) dimethyl quaternary ammonium methylsulfate. 
   
   
       20 . The method of  claim 17 , wherein the scavenger composition comprises from about 20 to about 98 percent by weight polyaliphatic amine, from about 2 to about 20 percent by weight catalyst and from 0 to about 78 percent by weight of a solvent, based on the weight of the composition. 
   
   
       21 . A hydrogen sulfide scavenger composition comprising a polyaliphatic amine and a catalyst, said polyaliphatic amine having the formula I:
   H 2 NRNH—(RNH) n —H  I   
     wherein R is an aliphatic radical and n is from about 0 to about 15. 
   
   
       22 . The scavenger composition of  claim 21 , wherein the aliphatic radical is a C 1 -C 30  alkyl, C 2 -C 30  alkenyl or C 1 -C 30  alkoxy. 
   
   
       23 . The scavenger composition of  claim 21 , wherein the polyaliphatic amine is a polyalkyleneamine. 
   
   
       24 . The scavenger composition of  claim 23 , wherein the polyalkyleneamine is selected from the group consisting of ethylenediamine, diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, propylethylenediamine, tetrabutylenepentamine, hexaethyleneheptamine, hexapentyleneheptamine, heptaethyleneoctamine, octaethylenenonamine, nonaethylenedecamine, decaethyleneundecamine, decahexyleneundecamine, undecaethylenedodecamine, dodecaethylenetridecamine, tridecaethylenedodecamine, dodecaethylenetriamine, tridecaethylenetetradecamine and N-tallow propylenediamine. 
   
   
       25 . The scavenger composition of  claim 21 , wherein the catalyst has formula TI:
   R 1 R 2 R 3 R 4 N + X −   II   
     wherein R 1 , R 2 , R 3  and R 4  are each independently alkyl groups having from 1 to 30 carbon atoms, hydroxyalkyl groups having from 1 to 30 carbon atoms or an aryl group having from 6 to 30 carbon atoms; and X is a halide or methyl sulfate. 
   
   
       26 . The scavenger composition of  claim 25 , wherein the catalyst is selected from the group consisting of dicocodimethylammonium chloride, ditallowedimethylammonium chloride, di(hydrogenated tallow alkyl) dimethyl quaternary ammonium methyl chloride, methyl bis(2-hydroxyethyl cocalkyl quaternary ammonium chloride, dimethyl(2-ethyl) tallow ammonium methyl sulfate and hydrogenated tallow alkyl (2-ethylhyexyl) dimethyl quaternary ammonium methylsulfate. 
   
   
       27 . The scavenger composition of  claim 21 , wherein the composition further comprises a solvent. 
   
   
       28 . The scavenger composition of  claim 27 , wherein the scavenger composition comprises from about 20 to about 98 percent by weight polyaliphatic amine, from about 2 to about 20 percent by weight catalyst and from 0 to about 78 percent by weight of a solvent, based on the weight of the composition. 
   
   
       29 . The method of  claim 7  wherein the polyaliphatic amine is diethylene triamine and the catalyst is alkyl benzyl ammonium chloride. 
   
   
       30 . The method of  claim 29  wherein the scavenger composition further comprises a solvent having a flashpoint of at least about 200° F.