INHIBITING CORROSION CAUSED BY AQUEOUS ALDEHYDE SOLUTIONS
Aldehydes useful as H 2 S sulfide scavengers may be corrosive to some metals such as steel, iron and aluminum, but the corrosive effect of the aldehydes may be mitigated by employing a corrosion inhibitor selected from the group consisting of a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof.
1 . A method for employing an aldehyde in an aqueous solution while mitigating corrosion of metal in contact with the aldehyde solution, the method comprising employing a corrosion inhibitor with the aldehyde wherein the corrosion inhibitor comprises a member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof.
2 . The method of claim 1 wherein the aldehyde is selected from the group consisting of glyoxal, acrolein, glutaraldehyde, formaldehyde, and combinations thereof.
3 . The method of claim 1 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof is selected from the group consisting of LiH 2 PO 4 , NaH 2 PO 4 , Na 2 HPO 4 , Na 3 HPO 4 , KH 2 PO 4 , K 2 HPO 4 , K 3 HPO 4 and combinations thereof.
4 . The method of claim 1 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof includes more than one cation.
5 . The method of claim 4 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof includes two or more cations selected from the group consisting of lithium, potassium, sodium and combinations thereof.
6 . The method of claim 1 wherein the aqueous aldehyde solution has an aldehyde concentration of from about 20 to about 90 weight percent.
7 . The method of claim 1 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof is present in the aqueous aldehyde solution at a concentration of from about 100 ppm to 30% (by wt.).
8 . The method of claim 1 wherein the aldehyde and corrosion inhibitor solution is employed at a pH range of from about 4.0 to about 9.0.
9 . The method of claim 8 , wherein the pH range may vary from about 4.5 to about 9.
10 . A process for exploring for or producing crude oil and/or natural gas comprising employing a H 2 S sulfide scavenger solution comprising an aldehyde and employing a corrosion inhibitor in the solution comprising a member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof.
11 . The process of claim 10 wherein the aldehyde is selected from the group consisting of glyoxal, acrolein, glutaraldehyde, formaldehyde, and combinations thereof.
12 . The process of claim 10 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof is selected from the group consisting of LiH 2 PO 4 ; NaH 2 PO 4 , Na 2 HPO 4 ; Na 3 HPO 4 ; KH 2 PO 4 , K 2 HPO 4 ; K 3 HPO 4 ; and combinations thereof.
13 . The process of claim 10 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof includes more than one cation.
14 . The process of claim 13 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof includes two or more cations selected from the group consisting of lithium, potassium, sodium, and combinations thereof.
15 . The process of claim 10 wherein the H 2 S sulfide scavenger solution has an aldehyde concentration of from about 20 to about 90 weight percent.
16 . The process of claim 10 wherein the member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof is present in the H 2 S sulfide scavenger solution at a concentration of from about 100 ppm to 30% (by wt.).
17 . The process of claim 10 wherein the H 2 S sulfide scavenger solution comprising aldehyde and member selected from the group consisting of a mono-basic soluble phosphate salt, a di-basic soluble phosphate salt, a tri-basic soluble phosphate salt, and combinations thereof, has a pH range of from about 4.0 to about 9.0.
18 . The process of claim 17 , wherein the pH range may vary from about 4.5 to about 9.
19 . The process of claim 10 wherein the H 2 S sulfide scavenger and corrosion inhibitor is atomized and injected into a gas stream.
20 . The process of claim 10 wherein the H 2 S sulfide scavenger and corrosion inhibitor is admixed with crude oil.