Process for corrosion inhibition utilizing an antimony-molybdenum salt corrosion inhibitor composition

Claim 2

A process for preventing corrosion of metals in contact with an alkaline liquid-acid gas absorbing solution comprising the step of adding to said solution an effective amount of corrosion inhibiting composition comprising an aqueous solution of soluble salts of antimony and molybdenum wherein the weight ratio of antimony salt to molybdenum salt ranges between about 0.05 to 1 and about 0.2 to 1.

Claim 3

The process of claim 1 wherein said antimony salt is selected from the group consisting of alkali metal antimony salts.

Claim 4

The process of claim 1 wherein the antimony salt is selected from the group consisting of antimonyl tartrate and antimonyl sulfate.

Claim 5

The process of claim 2 wherein the molybdenum salt is selected from the group consisting of alkali metal molybdenum salts.

Claim 6

The process of claim 4 wherein the alkali metal molybdenum salt is an alkali metal molybdate.

Claim 7

The process of claim 5 wherein the alkali metal antimony salt is potassium antimony tartrate.

Claim 8

The process of claim 5 wherein the alkali metal salt is sodium molybdate.

Claim 9

The process of claim 1 wherein the concentration of said corrosion inhibiting composition in said alkaline liquid absorbing solution ranges from about 0.01 to about 6 weight percent based on the total absorbing solution.

Claim 10

The process of claim 1 wherein said absorbing solution comprises an alkaline material selected from the group consisting of alkali metal salts, alkali metal hydroxides, amines and mixtures thereof.

Claim 11

The process of claim 9 wherein said alkaline material comprises potassium carbonate and an amine.

Claim 12

The process of claim 9 or claim 10 wherein said amine is a sterically hindered amine.

Claim 13

The process of claim 11 wherein said sterically hindered amine has the general formula: ##STR3## wherein R is a secondary or tertiary alkyl group and n is a integer 2, 3 or 4.

Claim 14

The process of claim 11 wherein the sterically hindered amine is a sterically hindered amine selected from the group consisting of N-cyclohexyl-1,2-ethanediamine; N-cyclohexyl-1,3,3-propanediamine; N-cyclohexyl-1,4-butanediamine; and N-cyclohexyl-1,5-pentanediamine.

Claim 15

The process of claim 11 wherein the absorbing solution further comprises a cosolvent.

Claim 16

The process of claim 14 wherein the diamine is N-cyclohexyl-1,3 propanediamine and the absorbing solution additionally contains an amino acid cosolvent containing 4-8 carbon atoms.

Claim 17

The process of claim 15 wherein the cosolvent is pipecolinic acid.

Claim 18

The process of claim 11 wherein the sterically hindered amine is selected from the group of sterically hindered amines having the structure: ##STR4## wherein R is hydrogen or methyl, and R' and R" are each selected from the group consisting of: (a) substituted or unsubstituted, linear or branched alkyl radicals having one to twenty carbon atoms; or (b) substituted or unsubstituted alkylene radicals together having three to six carbon atoms and combined to form a cyclic ring; or (c) substituted or unsubstituted cycloalkyl radicals having from four to eight ring carbon atoms; or (d) substituted or unsubstituted hydroxyalkyl radicals, linear or branched, having from one to twenty carbon atoms; or (e) substituted or unsubstituted aralkyl radicals having from seven to twenty carbon atoms, and wherein R"' is selected from the group consisting of substituted or unsubstituted linear alkyl radicals having from one to twenty carbon atoms.

Claim 19

The process of claim 17 wherein R is hydrogen, R" and R"' are each selected from the group consisting of C 1 to C 3 hydrocarbon radicals, and R"' is a methyl radical.

Claim 20

The process of claim 18 wherein the sterically hindered amine is selected from the group consisting of C 1 -C 3 hydrocarbon radicals, and R"' is a methyl radical.