Metal-based hydrogen sulfide scavenger and method of preparing same

Abstract

The present disclosure is related to a family of oil-based dispersions of organic and inorganic metal compounds for use as a hydrogen sulfide scavenger in asphalt, and the preparation thereof. These dispersions comprise organic and inorganic metal compounds, organic solvents, an organoclay suspension agent, an emulsifier and optionally a polymeric stabilizer. The organic and inorganic metal compounds are in the form of micron-sized particles. Copper-based dispersions are particularly effective at reducing the hydrogen sulfide emission of asphalt in the presence of polyphosphoric acid.

What is claimed is: 
     
         1 . A composition comprising: asphalt or asphalt mix; and a dispersion of a hydrogen sulfide scavenger in an organic solvent, wherein the dispersion further comprises an organoclay suspension agent and an emulsifier. 
     
     
         2 . The composition of  claim 1 , wherein the dispersion of the hydrogen sulfide scavenger further comprises a polymeric stabilizer. 
     
     
         3 . The composition of  claim 1 , wherein the hydrogen sulfide scavenger comprises a copper based compound. 
     
     
         4 . The composition of  claim 1 , wherein polyphosphoric acid is present in the asphalt or asphalt mix. 
     
     
         5 . The composition of  claim 3 , wherein the copper-based compound is selected from the group consisting of Caesium hexafluorocuprate(IV), Calcium copper titanate, Chlorophyllin, Chromated copper arsenate, Copper aspirinate, Copper benzoate, Copper chromite, Copper gluconate, Copper hydride, Copper ibuprofenate, Copper indium gallium selenide, Copper monosulfide, Copper oxide, Copper peptide GHK-Cu, Copper peroxide, Copper salicylate, Copper selenide, Copper silicide, Copper sulfide, Copper usnate, Copper(I) acetylide, Copper(I) bromide, Copper(I) chloride, Copper(I) cyanide, Copper(I) fluoride, Copper(I) hydroxide, Copper(I) iodide, Copper(I) nitrate, Copper(I) oxide, Copper(I) phosphide, Copper(I) sulfate, Copper(I) sulfide, Copper(I) thiocyanate, Copper(I)-thiophene-2-carboxylate, Copper(II) acetate, Copper(II) arsenate, Copper(II) azide, Copper(II) bromide, Copper(II) carbonate, Basic copper carbonate, Copper(II) chloride, Copper(II) fluoride, Copper(II) hydroxide, Copper(II) nitrate, Copper(II) oxide, Copper(II) perchlorate, Copper(II) phosphate, Copper(II) selenite, Copper(II) sulfate, Copper(II) tetrafluoroborate, Copper(II) triflate, Copper(III) oxide, Cuprate, Copper borate, Copper carboxylate and mixtures thereof. 
     
     
         6 . The composition of  claim 1 , wherein the hydrogen sulfide scavenger comprises an organic or inorganic metal compound from the group consisting of zinc, iron, chromium, manganese, molybdenum, selenium, strontium, cobalt and vanadium based compounds. 
     
     
         7 . The composition of  claim 1 , wherein the organic or inorganic metal compound is in the form of micron-sized particles. 
     
     
         8 . The composition of  claim 7 , wherein the particles have a diameter in the range of 0.5 to 500 microns. 
     
     
         9 . The composition of  claim 7 , wherein the particles have a diameter in the range of 1 to 50 microns. 
     
     
         10 . The composition of  claim 7 , wherein the particles have a diameter in the range of 1 to 10 microns. 
     
     
         11 . The composition of  claim 1 , wherein the solvent is an aliphatic or aromatic solvent. 
     
     
         12 . The composition of  claim 11 , wherein the solvent further comprises alcohol. 
     
     
         13 . The composition of  claim 12 , wherein the alcohol is not miscible with the aliphatic or aromatic solvent. 
     
     
         14 . The composition of  claim 12 , wherein the solvent is an alcohol-in-oil emulsion which provide better suspension properties and lower bulk viscosity for the fluid. 
     
     
         15 . The composition of  claim 1 , wherein the suspension agent is oil-soluble clay. 
     
     
         16 . The composition of  claim 1 , wherein the emulsifier is an oil-soluble surfactant with an HLB value of less than 10. 
     
     
         17 . The composition of  claim 1 , wherein the proportion of hydrogen sulfide scavenger is between 0.01% and 5% by weight with respect to the total weight of the asphalt composition. 
     
     
         18 . A method of preparing a hydrogen sulfide scavenger, the method comprising:
 adding an organo-clay and a surfactant to an oil;   stabilizing the oil with the organo-clay and the surfactant; and   adding a copper compound to the stabilized oil.   
     
     
         19 . The method of  claim 18 , wherein the copper compound comprises one or more of copper oxide and copper carbonate. 
     
     
         20 . The method of  claim 18 , wherein the organo-clay comprises organophillic clay.