Process of treating wool-scouring liquor and centrifuge effluent

Claim 2

A PROCESS FOR THE TREATMENT OF EMULSION-SCOURING LIQUOR CONTAINING A WOOL-GREASE-IN-WATER EMULSION, WHICH PROCESS COMPRISES IN COMBINATION: A. INTRODUCING THE EMULSION-SCOURING LIQUOR INTO A MEMBRANE UNTI CHARACTERIZED BY A SEMIPERMEABLE MEMBRANE ADAPTED TO PREVENT THE PASSAGE OF THE WOOL-GREASE-INWATER EMULSION AND SUSPENDED MATERIAL, AND TO PERMIT THE PASSAGE OF WATER; B. INTRODUCING THE EMULSION-SCOURING LIQUOR INTO AN EMULSION-CONCENTRATE FRACTION CONTAINING THE WOOL GREASE AND A PERMEATE FRACTION ESSENTIALLY FREE OF WIOL GREASE, EMULSION AND SUSPENDED PARTICLES, THE SEPARATION OF THE EMULSION-SCOURING LIQUOR CARRIED OUT AT A TEMPERATURE SUFFICIENT TO MAINTAIN DURING THE SEPARATION STEP A LIQUIDLIQUID EMULSION RATHER THAN A SOLID-LIQUID EMULSION OF THE WOOL GREASE IN THE AQUEOUS EMULSION-SCOURING LIQUOR; AND

Claim 3

The process of claim 1 which includes introducing aNd separating the emulsion-scouring liquor in an ultrafiltration membrane unit operated at a pressure ranging from about 20 to 200 psig.

Claim 4

The process of claim 1 wherein the temperature ranges from about 36* to 45*C.

Claim 5

The process of claim 1 wherein the emulsion-scouring liquor contains from about 1 to 8 percent wool grease, and wherein an emulsion-concentrate fraction contains from about two to six times the wool-grease concentration of the emulsion-scouring liquor.

Claim 6

The process of claim 1 wherein the emulsion-concentrate fraction contains from about 6 to 12 percent wool grease, and wherein the wool grease is recovered from the concentrate fraction by introducing the emulsion concentrate into a settling tank, and, thereafter, recovering the wool grease by filtering the sludge containing the wool grease from the settling tank.

Claim 7

The process of claim 1 which includes recovering the wool-grease fraction from the emulsion-concentrate fraction by introducing the emulsion-concentrate fraction into a centrifuge, and recovering the wool grease from the centrifuge sludge.

Claim 8

The process of claim 5 which includes recycling the effluent from a centrifuge for reuse in the step of preparing the emulsion-scouring liquor introduced into the membrane unit.

Claim 9

The process of claim 1 wherein the permeate fraction from the membrane unit is introduced into a reverse osmosis membrane unit to provide a low or essentially salt-free aqueous-permeate fraction for disposal or recycle.

Claim 10

The process of claim 1 which includes adding an acid to the emulsion-scouring liquor to reduce the pH to approximately 2 to 6 prior to separating the emulsion-scouring liquor in the membrane unit.

Claim 11

The process of claim 1 which includes: a. introducing the centrifuge emulsion effluent into a second membrane unit; b. separating in the second membrane unit a second emulsion-concentrate fraction rich in low-quality wool grease, and an aqueous permeate fraction; c. centrifuging the second emulsion concentrate in a second centrifuge, and recovering the low-quality wool grease; and d. recycling a second centrifuge emulsion back into the second membrane unit.

Claim 12

The process of claim 1 which includes: a. introducing the emulsion-concentrate fraction into a desludging centrifuge to obtain a desludged grease stream, an aqueous-effluent stream and sludge; b. centrifuging the desludged grease stream and recovering the centrifuged medium-quality grease; c. recycling the effluent stream to the inlet of the membrane unit; and d. recovering the grease from the sludge.

Claim 13

The process of claim 1 which includes: a. introducing the emulsion-scouring liquor prior to introduction into the membrane unit into a desludging centrifuge to obtain a desludge grease stream, an effluent-emulsion stream and sludge; b. removing the sludge; c. introducing the grease stream into a polishing centrifuge to obtain a high-quality centrifuge grease; d. recovering the centrifuged high-quality grease; e. introducing the membrane-concentrate fraction into a centrifuge to obtain a low-quality grease, an effluent stream and sludge; f. recycling the effluent stream back to the ultrafiltration membrane unit; and g. recovering a low-quality grease from the centrifuge.

Claim 14

The process of claim 1 which includes: a. adding an acid to the emulsion-concentrate fraction to reduce the pH to a value sufficient to crack the concentrate emulsion; and b. recovering the wool grease from the acid-cracked emulsion concentrate.

Claim 15

The process of claim 13 which includes: centrifuging the acid-cracked emulsion to obtain an aqueous-effluent stream, and to recover the wool grease; and recycling the aqueous effluent from the centrifuge into the membrane unit.

Claim 16

The process of claim 1 wherein the semipermeable membrane has pores in the range of from about 0.1 to 0.01 microNs, and wherein the temperature for which the separation of the emulsion-scouring liquor is carried out is at about 40*C or higher.

Claim 17

A process for the treatment of emulsion-scouring liquor containing a wool-grease-in-water emulsion, which process comprises: a. introducing the emulsion-scouring liquor containing from about 1 to 8 percent by weight of wool grease into an ultrafiltration membrane unit having a supported cellulose acetate membrane characterized by a pore size of about 0.1 to 0.01 microns, and adapted to prevent the passage of the wool-grease-in-water emulsion and suspended material and to permit the passage of water; b. separating the emulsion-scouring liquor into a concentrate fraction containing the wool grease and a permeate fraction essentially free of wool grease, the separation carried out at a temperature above the softening point of the wool grease, and sufficient to maintain the wool grease in a liquid-liquid, rather than a solid-liquid, emulsion during separation, and the separation carried out at a pressure of from about 20 to 200 psig.; c. withdrawing a wool-grease fraction containing from about two to six times the wool-grease concentration of the liquor; and d. centrifuging the wool-grease fraction to recover the wool grease therefrom.

Claim 18

A process for the treatment of emulsion-scouring liquor containing a wool-grease-in-water emulsion, which process comprises: a. introducing the emulsion-scouring liquor containing from about 1 to 8 percent by weight of wool grease into an ultrafiltration membrane unit having a supported cellulose acetate membrane characterized by a pore size of about 0.1 to 0.01 microns, and adapted to prevent the passage of the wool-grease-in-water emulsion and suspended material and to permit the passage of water; b. separating the emulsion-scouring liquor into a concentrate fraction containing the wool grease and a permeate fraction essentially free of wool grease, the separation carried out at a temperature above the softening point of the wool grease, and sufficient to maintain the wool grease in a liquid-liquid, rather than a solid-liquid, emulsion during separation, and the separation carried out at a pressure of from about 20 to 200 psig.; c. withdrawing a wool-grease fraction containing from about two to six times the wool-grease concentration of the liquor; and d. centrifuging the wool-grease fraction to recover the wool grease therefrom.