Recovery and reuse of anionic surfactants from aqueous solutions

A method of recovering at least 95% of a substantially pure anionic surfactant from an aqueous surfactant-containing solution for reuse comprising the steps of:

• (i) preparing an aqueous solution comprising a surfactant composition comprising surfactant selected from the group consisting of:
• ##STR8## and mixtures thereof, wherein R is selected from the group consisting of alkyl, aryl, alkaryl, alkylarylalkyl, aryalkyl, alkylamidoalkyl, alkylaminoalkyl, R.sub.1 --C(O)--›O(EO).sub.a (PO).sub.b !.sub.n --R.sub.2 -- (O).sub.p -- and the hydroxy-substituted derivatives thereof wherein the alkyl groups contain from 1 to about 12 carbon atoms, the aryl group is a phenyl, diphenyl, diphenylether, or naphthalene moiety, with the proviso that the total number of carbon atoms in any R group is no more than 18,
• R.sub.1 is C.sub.12 -C.sub.22 alkyl,
• R.sub.2 is C.sub.1 -C.sub.15 alkylene,
• R.sub.4 is C.sub.4 -C.sub.8 alkyl or C.sub.4 -C.sub.8 alkylamido,
• R.sub.5 is C.sub.4 -C.sub.8 alkyl or Y
• R.sub.6 is hydrogen or C.sub.4 -C.sub.12 alkyl,
• M is hydrogen, alkali metal or
• --›R.sub.3 --›EO).sub.n (PO).sub.b (BO).sub.c !.sub.n --O!.sub.q --P(O)(OM).sub.2,
• R.sub.3 is C.sub.1 -C.sub.5 alkylene,
• Y is a counterion,
• EO represents an ethyleneoxy radical, PO represents a propyleneoxy radical, and BO represents a butoxy radical,
• a, b, and c each are independently 0 to 50, wherein the EO. PO, and BO can be randomly mixed or in discrete blocks,
• n is 0 or 1,
• m is 1 and/or 2,
• p is 0 or 1;
• q is 1 to about 10;
• ii) ultrafiltering the aqueous surfactant-containing solution at a pressure of no greater than 45 psi to generate a permeate;
• and
• iii) recovering surfactant from the permeate
• EO represents an ethyleneoxy radical, PO represents a propyleneoxy radical, and BO represents a butoxy radical,
• a, b, and c each are independently 0 to 50, wherein the EO, PO, and BO can be randomly mixed or in discrete blocks,
• n is 0 or 1,
• p is 0 or 1, and
• ii) ultrafiltering the aqueous surfactant-containing solution to generate a permeate and
• iii) recovering surfactant from the permeate.

A method of recovering at least 95% of a substantially pure anionic surfactant from an aqueous surfactant-containing solution for reuse comprising the steps of:

• i) preparing an aqueous solution comprising a surfactant composition comprising surfactant of the formula:
• ›R--›O(EO).sub.a (PO).sub.b !.sub.n --SO.sub.3.sup.-Y.sup.+
• wherein R is selected from the group consisting of alkyl, aryl, alkaryl, alkylarylalkyl, aryalkyl, alkylamidoalkyl, alkylaminoalkyl, R.sub.1 --C(O)--›O(EO).sub.a (PO).sub.b !.sub.n --R.sub.2 --(O).sub.p -- and the hydroxy substituted derivatives thereof
• wherein the alkyl groups contain from 1 to about 12 carbon atoms, the aryl group is a phenyl, diphenyl diphenylether;
• or naphthalene moiety, with the proviso that the total number of carbon atoms in any R group is no more than 18,
• R.sub.1 is C.sub.12 -C.sub.22 alkyl,
• R.sub.2 is C.sub.1 -C.sub.18 alkylene,
• Y is a counterion,
• EO represents an ethyleneoxy radical, PO represents a propyleneoxy radical, and BO represents a butoxy radical,
• a, b, and c each are independently 0 to 50, wherein the EO, PO, and BO can be randomly mixed or in discrete blocks,
• n is 0 or 17
• p is 0 or 1, and
• ii) ultrafiltering the aqueous surfactant-containing solution at a pressure of no greater than 45 psi to generate a permeate;
• and
• iii) recovering surfactant from the permeate.

A method of recovering at least 95% of a substantially pure anionic surfactant from an aqueous surfactant-containing solution for reuse comprising the steps of:

• i) preparing an aqueous solution comprising a surfactant composition comprising surfactant of the formula:
• ›R--›O(EO).sub.a (PO).sub.b !.sub.n --!.sub.m --P(O)(OM).sub.2
• wherein R is selected from the group consisting of alkyl, aryl, alkaryl, alkylarylalkyl, aryalkyl, alkylamidoalkyl, alkylaminoalkyl, R.sub.1 --C(O)--›O(EO).sub.a (PO).sub.b !.sub.n --R.sub.2 --(O).sub.p -- and the hydroxy substituted derivatives thereof wherein alkyl groups contain from 1 to about 12 carbon atoms, the aryl group is a phenyl, diphenyl, diphenylether, or naphthalene moiety, with the proviso that the total number of carbon atoms in any R group is no more than 18,
• R.sub.1 is C.sub.12 -C.sub.22 alkyl,
• R.sub.2 is C.sub.1 -C.sub.18 alkylene, and
• M is hydrogen, alkali metal or
• --R.sub.3 --›EO).sub.a (PO).sub.b (BO).sub.c !.sub.n --O!.sub.q --P(O)(OM).sub.2,
• R.sub.3 is C.sub.1 -C.sub.5 alkylene,
• EO represents an ethyleneoxy radical, PO represents a propyleneoxy radical, and BO represents a butoxy radical,
• a, b, and c each are independently 0 to 50, wherein the EO, PO, and BO can be randomly mixed or in discrete blocks,
• n is 0 or 1;
• m is 1 and/or 2,
• p is 0 or 1, and
• q is 1 to about 10;
• ii) ultrafiltering the aqueous surfactant-containing solution at a pressure of no more than 45 psi to generate a permeate;
• and
• iii) recovering surfactant from the permeate.

A method of recovering at least 95% of a substantially pure anionic surfactant from an aqueous surfactant-containing solution for reuse comprising the steps of:

• i) preparing an aqueous solution comprising a surfactant composition comprising surfactant of the formula:
• ##STR9## wherein R.sub.5 is C.sub.4 -C.sub.8 alkyl or C.sub.4 -C.sub.8 alkylamido,
• R.sub.5 is C.sub.4 -C.sub.8 alkyl or Y, and
• Y is a counterion;
• ii) ultrafiltering the aqueous surfactant-containing solution at a pressure of no more than 45 psi to generate a permeate;
• and
• iii) recovering surfactant from the permeate.

A method of recovering at least 95% of a substantially pure anionic surfactant from an aqueous surfactant-containing solution for reuse comprising the steps of:

• i) preparing an aqueous solution comprising a surfactant composition comprising surfactant of the formula:
• R--›O(EO).sub.a (PO).sub.b !.sub.n --CH.sub.2 --C(O)--O.sup.- Y.sup.+
• wherein
• R is selected from the group consisting of alkyl, aryl, alkaryl, alkylarylalkyl, aryalkyl, alkylamidoalkyl, alkylaminoalkyl, R.sub.1 --C(O)--›O(EO).sub.a (PO).sub.b !.sub.n --R.sub.2 --R.sub.2 --(O).sub.p -- and the hydroxy substituted derivatives thereof wherein the alkyl groups contain from 1 to about 12 carbon atoms, the aryl group is a phenyl, diphenyl, diphenylether, or naphthalene moiety, with the proviso that the total number of carbon atoms in any R group is no more than 18,
• R.sub.1 is C.sub.12 -C.sub.22 alkyl,
• R.sub.2 is C.sub.1 -C.sub.18 alkylene, and
• Y is a counterion,
• EO represents an ethyleneoxy radical, PO represents a propyleneoxy radical, and BO represents a butoxy radical,
• a, b, and c each are independently 0 to 50, wherein the EO, PO, and BO can be randomly mixed or in discrete blocks,
• n is 0 or 1;
• ii) ultrafiltering the aqueous surfactant-containing solution at a pressure of no more than 45 psi to generate a permeate and
• iii) recovering surfactant from the permeate.

A method of recovering at least 95% of a substantially pure anionic surfactant from an aqueous surfactant-containing solution for reuse comprising the steps of:

• i) preparing an aqueous solution comprising surfactant of the formula:
• ##STR10## wherein R.sub.6 is hydrogen or C.sub.4 -C.sub.12 alkyl, and
• M is hydrogen, alkali metal, or
• --›R.sub.3 --›(EO).sub.a (PO).sub.b (BO).sub.c !.sub.n --O!.sub.q --P(O)(OM).sub.2
• wherein R.sub.3 is C.sub.1 -C.sub.5 alkylene,
• EO represents an ethyleneoxy radical, PO represents a propyleneoxy radical, and BO represents a butoxy radical,
• a, b, and c each are independently 0 to 50, wherein the EO, PO, and BO can be randomly mixed or in discrete blocks,
• n is 0 or 1;
• and
• q is 1 to about 10,
• ii) ultrafiltering the aqueous surfactant-containing solution at a pressure of no more than 45 psi to generate a permeate;
• and
• iii) recovering surfactant from the permeate.