US 5,347,003 AGranted

Methods for regenerating a sulfur scavenging compound from a product of a sulfur scavenging reaction

AssigneeQuaker Chemical Corporation

InventorsEdward A. Trauffer, Robert D. Evans

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Abstract

Methods are provided whereby an N-C-N compound is regenerated from a product of a sulfur scavenging reaction, in which said N-C-N compound removes a sulfur atom from a sulfur compound, to form the original N-C-N compound. The N-C-N compound is represented by the formula (I): ##STR1## The product includes a hetero compound having sulfur, carbon and nitrogen atoms in its backbone. In one embodiment, the product is mixed with (1) a nitrogen compound represented by the formula (II): ##STR2## and (2) an alkaline compound selected from alkali metal, alkaline earth metal and transition metal compounds, to form a solution, slurry or dispersion. The hetero compound is reacted with the nitrogen compound in the presence of the alkaline compound, such that a sulfur atom of the hetero compound is replaced by a nitrogen atom of the nitrogen compound. If necessary, the pH of the solution may be adjusted to about 8 to about 13 to facilitate the reaction. In alternative embodiments, the product also includes an amine complex. The nitrogen atom being substituted for the sulfur atom in the hetero compound may be obtained from either the nitrogen compound or the amine complex.

Claims17

Dependent claims

A method for regenerating an N-C-N compound from a product of a sulfur scavenging reaction in which said N-C-N compound removes a sulfur atom from a sulfur compound, said N-C-N compound being represented by the formula (I):

##STR8## where n is an integer of 1 to 100, and each of R.sup.1, R.sup.2 R.sup.3, R.sup.4, and R.sup.5 is independently selected from the group consisting of:
(i) hydrogen;
(ii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons;
(iii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons comprising at least one heteroatom selected from the group consisting of nitrogen, oxygen, sulfur and halogen;
(iv) a substituted or unsubstituted polymeric chain;
and
(v) a direct bond to any other of R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5, said product comprising a hetero compound having sulfur, carbon and nitrogen atoms in its backbone, the method comprising the steps of:
(a) mixing said product with:
(1) a nitrogen compound represented by the formula (II):
##STR9## where each of R.sup.6 and R.sup.7 are independently selected from the group consisting of:
(i) hydrogen;
(ii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons;
(iii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons comprising at least one heteroatom selected from the group consisting of boron, nitrogen, oxygen, sulfur and halogen;
and
(iv) a substituted or unsubstituted polymeric chain;
and salts thereof;
and
(2) an alkaline compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound and a transiton metal compound, to form one of a solution, slurry or dispersion;
(b) reacting said hetero compound with said nitrogen compound in the presence of said alkaline compound, such that a sulfur atom of said hetero compound is replaced by a nitrogen atom of said nitrogen compound;
and
(c) if necessary, adjusting the pH of said solution to about 8 to about 13.

18 more elements

##STR11## where n is an integer of 1 to 100, and each of R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5 is independently selected from the group consisting of:
(i) hydrogen;
(ii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons;
(iii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons comprising at least one heteroatom selected from the group consisting of nitrogen, oxygen, sulfur and halogen;
(iv) a substituted or unsubstituted polymeric chain;
and
(v) a direct bond to any other of R.sup.1, R.sup.2, R.sup.3, R.sup.4, and R.sup.5, said product comprising a hetero compound and an amine complex, said hetero compound having sulfur, carbon and nitrogen atoms in its backbone, the method comprising the steps of:
(a) mixing said product with:
(1) a nitrogen compound represented by the formula (II):
##STR12## where each of R.sup.6 and R.sup.7 are independently selected from the group consisting of:
(i) hydrogen;
(ii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons;
(iii) a substituted or unsubstituted, saturated or unsaturated, linear, branched or cyclic hydrocarbon chain of 1 to 20 carbons comprising at least one heteroatom selected from the group consisting of boron, nitrogen, oxygen, sulfur and halogen;
and
(iv) a substituted or unsubstituted polymeric chain;
and salts thereof;
and
(2) an alkaline compound selected from the group consisting of an alkali metal compound, an alkaline earth metal compound and a transition metal compound to form one of a solution, slurry or dispersion;
(b) reacting said hetero compound with at least one of said amine complex and said nitrogen compound in the presence of said alkaline compound, such that a sulfur atom of said hetero compound is replaced by a nitrogen atom selected from the group consisting of said amine complex and said nitrogen compound;
and
(c) if necessary, adjusting the pH of said solution to about 8 to about 13.

18 more elements

Dependencies are inferred from the claim text.