Composition and method for elimination of hydrogen sulfide and mercaptans

Abstract

A scavenging composition and method for scavenging hydrogen sulfide and/or mercaptans from fluids. The scavenging composition comprises an alkali metal nitrite and a nitrogen-containing scavenger, and optionally an inorganic base, as a hydrogen sulfide and/or a mercaptan scavenger for hydrocarbon fluids, particularly for crude oil, field oil, fuel oil, straight run distillates, cracked distillates, residual fuels, natural gas, petroleum associated gas and the like.

1 . A method for scavenging a sulfur-containing compound contained in a hydrocarbon medium, wherein the sulfur-containing compound is hydrogen sulfide, a mercaptan or a combination thereof, the method comprising:
 contacting the hydrocarbon medium with an aqueous solution comprising at least one alkali metal nitrite and at least one organic nitrogen-containing scavenger.   
     
     
         2 . The method of  claim 1 , wherein the aqueous solution comprises from 1 to 40 wt. % of the at least one alkali metal nitrite, and from 1 to 40 wt. % of the at least one organic nitrogen-containing scavenger. 
     
     
         3 . The method of  claim 1 , wherein the aqueous solution comprises from 14 to 35.6 wt. % of the at least one alkali metal nitrite, and from 3.1 to 30 wt. % of the at least one organic nitrogen-containing scavenger. 
     
     
         4 . The method of  claim 1 , wherein the aqueous solution further comprises at least one inorganic base. 
     
     
         5 . The method of  claim 4 , wherein the aqueous solution comprises from 1 to 40 wt. % of the at least one alkali metal nitrite, from 1 to 40 wt. % of the at least one organic nitrogen-containing scavenger, and from 0 to 15 wt. % of the at least one inorganic base. 
     
     
         6 . The method of  claim 4 , wherein the aqueous solution comprises from 15.4 to 35 wt. % of the at least one alkali metal nitrite, from 3.1 to 30 wt. % of the at least one organic nitrogen-containing scavenger, and from 0.5 to 14 wt. % of the at least one inorganic base. 
     
     
         7 . The method of  claim 1 , wherein the hydrocarbon medium is a gas. 
     
     
         8 . The method of  claim 1 , wherein the hydrocarbon medium is a gas; and
 wherein the aqueous solution comprises from 14 to 35 wt. % of the at least one alkali metal nitrite, and from 4 to 30 wt. % of the at least one organic nitrogen-containing scavenger.   
     
     
         9 . The method of  claim 4 , wherein the hydrocarbon medium is a gas; and
 wherein the aqueous solution comprises from 14 to 35 wt. % of the at least one alkali metal nitrite, from 4 to 30 wt. % of the at least one organic nitrogen-containing scavenger, and from 0.5 to 14 wt. % of the at least one inorganic base.   
     
     
         10 . The method of  claim 1 , wherein the hydrocarbon medium is a gas; and wherein the aqueous solution comprises from 10 to 25 wt. % of the at least one alkali metal nitrite, from 5 to 25 wt. % of the at least one organic nitrogen-containing scavenger, and from 0 to 10 wt. % of at least one inorganic base. 
     
     
         11 . The method of  claim 4 , wherein the hydrocarbon medium is a gas; and wherein the aqueous solution comprises from 14 to 20 wt. % of the at least one alkali metal nitrite, from 8 to 22 wt. % of the at least one organic nitrogen-containing scavenger, and from 2 to 8 wt. % of the at least one inorganic base 
     
     
         12 . The method of  claim 1 , wherein the hydrocarbon medium is a liquid. 
     
     
         13 . The method of  claim 1 , wherein the hydrocarbon medium is a liquid; and
 wherein the aqueous solution comprises from 15.4 to 35.6 wt. % of the at least one alkali metal nitrite, and from 3.1 to 23.2 wt. % of the at least one organic nitrogen-containing scavenger.   
     
     
         14 . The method of  claim 4 , wherein the hydrocarbon medium is a liquid; and
 wherein the aqueous solution comprises from 15.4 to 35.6 wt. % of the at least one alkali metal nitrite, from 3.1 to 23.2 wt. % of the at least one organic nitrogen-containing scavenger, and from 3.13 to 14 wt. % of the at least one inorganic base.   
     
     
         15 . The method of  claim 1 , wherein the at least one alkali metal nitrite is sodium nitrite, potassium nitrite or a combination thereof. 
     
     
         16 . The method of  claim 1 , wherein the at least one organic nitrogen-containing scavenger is monoethanolamine (MEA); MEA triazine; diethanolamine (DEA); N-methyldiethanolamine (MDEA); diisopropylamine; diglycolamine (DGA); triethanolamine (TEA); alkylene polyamine; an alkylene polyamine/formaldehyde reaction product; a reaction product of ethylene diamine with formaldehyde; a N-butylamine formaldehyde reaction product; monomethylamine (MMA); monoethylamine; dimethylamine; dipropylamine; trimethylamine; triethylamine; tripropylamine; monomethanolamine; dimethanolamine; trimethanolamine; monoisopropanolamine; dipropanolamine; tripropanolamine; N-methylethanolamine; dimethyl ethanol amine; methyl diethanolamine; dimethyl amino ethanol; diamine; morpholine; N-methylmorpholine; pyrrolidone; piperazine; N,N-dimethylpiperazine; piperidine; N-methylpiperidine; piperidone; alkylpyridine; aminomethylcyclopentylamine; 1-2 cyclohexanediamine; or a combination thereof. 
     
     
         17 . The method of  claim 1 , wherein the at least one organic nitrogen-containing scavenger comprises an alcohol amine. 
     
     
         18 . The method of  claim 1 , wherein the at least one organic nitrogen-containing scavenger comprises a di-alcohol amine, tri-alcohol amine, or a combination thereof. 
     
     
         19 . The method of  claim 1 , wherein the at least one organic nitrogen-containing scavenger is selected from the group consisting of diethanolamine (DEA); N-methyldiethanolamine (MDEA); triethanolamine (TEA); dimethanolamine; trimethanolamine; dipropanolamine; tripropanolamine; and combinations thereof. 
     
     
         20 . The method of  claim 1 , wherein the at least one inorganic base is an alkali metal hydroxide. 
     
     
         21 . The method of  claim 1 , wherein the contacting is done in the presence of a compound comprising a transition metal in a high oxidation state. 
     
     
         22 . The method of  claim 1 , wherein the hydrocarbon medium is petroleum, a gas, a water/oil emulsion, a mixture of a water/oil emulsion and gas, a residual fuel, a straight-run fraction and distillate of secondary processing, a low-molecular hydrocarbon, an aromatic solvent, or a mixture of gases. 
     
     
         23 . A method for scavenging a sulfur-containing compound contained in a hydrocarbon medium, wherein the sulfur-containing compound is hydrogen sulfide, a mercaptan or a combination thereof, the method comprising:
 contacting the hydrocarbon medium with an aqueous solution of at least one alkali metal nitrite, and an aqueous solution of at least one organic nitrogen-containing scavenger;   wherein the at least one alkali metal nitrite is present in a relative amount of 1 mole of the alkali metal nitrite per 2-4 moles of the sulfur in the sulfur-containing compound, and the at least one organic nitrogen-containing scavenger is present in a relative amount of 1 mole of nitrogen in the organic nitrogen-containing scavenger per 2-20 moles of the sulfur in the sulfur-containing compound; and   wherein the hydrocarbon medium is a liquid.   
     
     
         24 . The method of  claim 23 , further comprising:
 contacting the hydrocarbon medium with an aqueous solution of at least one inorganic base;   wherein the at least one inorganic base is present in a relative amount of 1 mole of the inorganic base per 2-20 moles of the sulfur in the sulfur-containing compound.   
     
     
         25 . The method of  claim 23 , wherein a single aqueous solution comprises the aqueous solution of at least one alkali metal nitrite and the aqueous solution of at least one organic nitrogen-containing scavenger. 
     
     
         26 . The method of  claim 24 , wherein a single aqueous solution comprises the aqueous solution of at least one alkali metal nitrite, the aqueous solution of at least one organic nitrogen-containing scavenger, and the aqueous solution of at least one inorganic base. 
     
     
         27 . A scavenger composition comprising:
 an aqueous solution comprising at least one alkali metal nitrite, and at least one organic nitrogen-containing scavenger.   
     
     
         28 . The scavenger composition of  claim 27 , wherein the aqueous solution comprises from 1 to 40 wt. % of the at least one alkali metal nitrite, and from 1 to 40 wt. % of the at least one organic nitrogen-containing scavenger. 
     
     
         29 . The scavenger composition of  claim 27 , wherein the aqueous solution comprises from 14 to 35.6 wt. % of the at least one alkali metal nitrite, and from 3.1 to 30 wt. % of the at least one organic nitrogen-containing scavenger. 
     
     
         30 . The scavenger composition of  claim 27 , wherein the aqueous solution further comprises at least one inorganic base. 
     
     
         31 . The scavenger composition of  claim 30 , wherein the aqueous solution comprises from 1 to 40 wt. % of the at least one alkali metal nitrite, from 1 to 40 wt. % of the at least one organic nitrogen-containing scavenger, and from greater than 0 to 15 wt. % of the at least one inorganic base. 
     
     
         32 . The scavenger composition of  claim 30 , wherein the aqueous solution comprises from 14 to 35.6 wt. % of the at least one alkali metal nitrite, from 3.1 to 30 wt. % of the at least one organic nitrogen-containing scavenger, and from 0.5 to 14 wt. % of the at least one inorganic base. 
     
     
         33 . The scavenger composition of  claim 27 , wherein the aqueous solution comprises from 10 to 25 wt. % of the at least one alkali metal nitrite, from 5 to 25 wt. % of the at least one organic nitrogen-containing scavenger, and from 0 to 10 wt. % of at least one inorganic base. 
     
     
         34 . The scavenger composition of  claim 30 , wherein the aqueous solution comprises from 14 to 20 wt. % of the at least one alkali metal nitrite, from 8 to 22 wt. % of the at least one organic nitrogen-containing scavenger, and from 2 to 8 wt. % of the at least one inorganic base. 
     
     
         35 . The scavenger composition of  claim 27 , wherein the at least one alkali metal nitrite is sodium nitrite, potassium nitrite or a combination thereof. 
     
     
         36 . The scavenger composition of  claim 27 , wherein the at least one organic nitrogen-containing scavenger is monoethanolamine (MEA); MEA triazine; diethanolamine (DEA); N-methyldiethanolamine (MDEA); diisopropylamine; diglycolamine (DGA); triethanolamine (TEA); alkylene polyamine; an alkylene polyamine/formaldehyde reaction product; a reaction product of ethylene diamine with formaldehyde; a N-butylamine formaldehyde reaction product; monomethylamine (MMA); monoethylamine; dimethyl amine; dipropylamine; trimethylamine; triethylamine; tripropylamine; monomethanolamine; dimethanolamine; trimethanolamine; monoisopropanolamine; dipropanolamine; tripropanolamine; N-methylethanolamine; dimethyl ethanol amine; methyl diethanolamine; dimethyl amino ethanol; diamine; morpholine; N-methylmorpholine; pyrrolidone; piperazine; N,N-dimethylpiperazine; piperidine; N-methylpiperidine; piperidone; alkylpyridine; aminomethylcyclopentylamine; 1-2 cyclohexanediamine; or a combination thereof. 
     
     
         37 . The scavenger composition of  claim 27 , wherein the at least one organic nitrogen-containing scavenger comprises an alcohol amine. 
     
     
         38 . The scavenger composition of  claim 27 , wherein the at least one organic nitrogen-containing scavenger comprises a di-alcohol amine, tri-alcohol amine, or a combination thereof. 
     
     
         39 . The scavenger composition of  claim 27 , wherein the at least one organic nitrogen-containing scavenger is selected from the group consisting of diethanolamine (DEA); N-methyl diethanolamine (MDEA); triethanolamine (TEA); dimethanolamine; trimethanolamine; dipropanolamine; tripropanolamine; and combinations thereof. 
     
     
         40 . The scavenger composition of  claim 27 , wherein the at least one inorganic base is an alkali metal hydroxide.