Oil-water separation process

Claim 1

A METHOD FOR TREATING A FLUID SYSTEM CONTAINING OIL HAVING AN API GRAVITY VALUE FROM ABOUT 11 TO ABOUT 70, WATER AND PARTICULATE SOLIDS TO PRODUCE CLARIFIED WATER, SOLIDS-FREE OIL AN OIL-FREE SOLIDS WHICH COMPRISES: A. FILTERING SAID FLUID SYSTEM THROUGH A FINELY DIVIDED OIL AND WATER INSOLUBLE FILTER MEDIA CONTAINING FROM ABOUT 2 TO ABOUT 8 CUBIC FEET OF FILTER MATERIAL FOR EACH SQUARE FOOT OF FILTER MEDIA SURFACE AREA, AT A FLOW RATE FROM ABOUT 10 TO ABOUT 35 GALLONS PER MINUTE PER SQUARE FOOT OF FILTER MEDIA SURFACE AREA TO RETAIN PARTICULATE SOLIDS AND OIL WITHIN THE FILTER MEDIA AND PASS AN EFFLUENT SELECTED FROM THE GROUP CONSISTING OF: CLARIFIED WATER AND A MIXTURE OF SOLIDS-FREE OIL AND WATER WHICH SEPARATES INTO DEFINED LAYERS OF SOLIDS-FREE OIL AND CLARIFIED WATER, SAID MIXTURE BEING ATTAINED WHEN THE OIL CONTENT OF THE FLUID SYSTEM IS IN EXCESS OF ABOUT 1% BY WEIGHT, SAID FILTER MEDIA HAVING: I. A MININUM PARTICLE MESH SIZE WITHIN THE RANGE FROM ABOUT 3 TO ABOUT 30 AND A MAXIMUM PARTICLE MESH SIZE WITHIN THE RANGE FROM ABOUT 30 TO ABOUT 100 WITH THE RANGE BETWEEN SAID MINIMUM AND MAXIMUM PARTICLE MESH SIZES BEING AT LEAST 20 MESH, II. A MEDIAN PARTICLE MESH SIZE, BY WEIGHT, WHICH IS A FUNCTION OF THE API GRAVITY VALUE OF THE OIL, SAID MEDIAN PARTICLE MESH SIZE FALLING WITHIN THE RANGE DEFINED BY MAXIMUM AND MINIMUM LINEAR VALUE VARYING FROM DIRECTLY WITH THE LINEAR VALUE OF SAID API GRAVITY, SAID MEDIAN MESH SIZE MAXIMUM LINEAR VALUE VARYING FROM ABOUT 18 TO 62 AND SAID MEDIAN MESH SIZE MINIMUM LINERAR VALUE VARYING FROM ABOUT 10 TO 54 AS SAID API GRAVITY VALUE VARIES FROM ABOUT 11 TO 70, AND III. A PARTICLE SIZE DISTRUBUTION PATTERN EXTENDING FROM THE MINIMUM PARTICLE MESH SIZE TO THE MAXIMUM PARTICLE MESH SIZE CHARACTERIZED IN THAT THE WEIGHT OF THE FILTER MEDIA SUBSTANTIALLY UNIFORMLY AND PROGRESSIVELY INCREASES FROM: A. ABOUT 0 TO 50 PERCENT AS THE FILTER MEDIA PARTICLE MESH SIZE VARIES FROM THE MINIMUM PARTICLE MESH SIZE TO THE MEDIAN PARTICLE MESH SIZE, AND B. ABOUT 0S TO 50 WEIGHT PRECENT AS THE FILTER MEDIA PARTICLE MESH SIZE VARIES FROM THE MAXIMUM PARTICLE MESH SIZE TO THE MEDIAN PARTICLE MESH SIZE, AND B. PERIODICALLY REGENERATING THE FILTER MEDIA BY: PASSING AN OIL STRIPPING COMPOSITION THROUGH SAID FILTER MEDIA IN THE SAME DIRECTION OF FLOW AS THAT OF THE FLUID SYSTEM TOREMOVE SOLIDS-FREE OIL FROM SAID FILTER MEDIA, AND THEREAFTER BACKWASHING SAID FILTER MEDIA IN A DIRECTION COUNTERCURRENT TO THE FLOW OF SAID FLUID SYSTEM AT A RATE FROM ABOUT 10 TO ABOUT 55 GALLONS PER MINUTE PER SQUARE FOOT OF FILTER MEDIA SURFACE AREA TO REMOVE OILFREE PARTICULATE SOLIDS FROM SAID FILTER MEDIA.

Claim 2

A METHOD FOR TREATING A FLUID SYSTEM CONTAINING OIL HAVING AN API GRAVITY VALUE FROM ABOUT 11 TO ABOUT 70, WATER AND PARTICULATE SOLIDS TO PRODUCE CLARIFIED WATER, SOLIDS-FREE OIL AN OIL-FREE SOLIDS WHICH COMPRISES: A. FILTERING SAID FLUID SYSTEM THROUGH A FINELY DIVIDED OIL AND WATER INSOLUBLE FILTER MEDIA CONTAINING FROM ABOUT 2 TO ABOUT 8 CUBIC FEET OF FILTER MATERIAL FOR EACH SQUARE FOOT OF FILTER MEDIA SURFACE AREA, AT A FLOW RATE FROM ABOUT 10 TO ABOUT 35 GALLONS PER MINUTE PER SQUARE FOOT OF FILTER MEDIA SURFACE AREA TO RETAIN PARTICULATE SOLIDS AND OIL WITHIN THE FILTER MEDIA AND PASS AN EFFLUENT SELECTED FROM THE GROUP CONSISTING OF: CLARIFIED WATER AND A MIXTURE OF SOLIDS-FREE OIL AND WATER WHICH SEPARATES INTO DEFINED LAYERS OF SOLIDS-FREE OIL AND CLARIFIED WATER, SAID MIXTURE BEING ATTAINED WHEN THE OIL CONTENT OF THE FLUID SYSTEM IS IN EXCESS OF ABOUT 1% BY WEIGHT, SAID FILTER MEDIA HAVING: I. A MININUM PARTICLE MESH SIZE WITHIN THE RANGE FROM ABOUT 3 TO ABOUT 30 AND A MAXIMUM PARTICLE MESH SIZE WITHIN THE RANGE FROM ABOUT 30 TO ABOUT 100 WITH THE RANGE BETWEEN SAID MINIMUM AND MAXIMUM PARTICLE MESH SIZES BEING AT LEAST 20 MESH, II. A MEDIAN PARTICLE MESH SIZE, BY WEIGHT, WHICH IS A FUNCTION OF THE API GRAVITY VALUE OF THE OIL, SAID MEDIAN PARTICLE MESH SIZE FALLING WITHIN THE RANGE DEFINED BY MAXIMUM AND MINIMUM LINEAR VALUE VARYING FROM DIRECTLY WITH THE LINEAR VALUE OF SAID API GRAVITY, SAID MEDIAN MESH SIZE MAXIMUM LINEAR VALUE VARYING FROM ABOUT 18 TO 62 AND SAID MEDIAN MESH SIZE MINIMUM LINERAR VALUE VARYING FROM ABOUT 10 TO 54 AS SAID API GRAVITY VALUE VARIES FROM ABOUT 11 TO 70, AND III. A PARTICLE SIZE DISTRUBUTION PATTERN EXTENDING FROM THE MINIMUM PARTICLE MESH SIZE TO THE MAXIMUM PARTICLE MESH SIZE CHARACTERIZED IN THAT THE WEIGHT OF THE FILTER MEDIA SUBSTANTIALLY UNIFORMLY AND PROGRESSIVELY INCREASES FROM: A. ABOUT 0 TO 50 PERCENT AS THE FILTER MEDIA PARTICLE MESH SIZE VARIES FROM THE MINIMUM PARTICLE MESH SIZE TO THE MEDIAN PARTICLE MESH SIZE, AND B. ABOUT 0S TO 50 WEIGHT PRECENT AS THE FILTER MEDIA PARTICLE MESH SIZE VARIES FROM THE MAXIMUM PARTICLE MESH SIZE TO THE MEDIAN PARTICLE MESH SIZE, AND B. PERIODICALLY REGENERATING THE FILTER MEDIA BY: PASSING AN OIL STRIPPING COMPOSITION THROUGH SAID FILTER MEDIA IN THE SAME DIRECTION OF FLOW AS THAT OF THE FLUID SYSTEM TOREMOVE SOLIDS-FREE OIL FROM SAID FILTER MEDIA, AND THEREAFTER BACKWASHING SAID FILTER MEDIA IN A DIRECTION COUNTERCURRENT TO THE FLOW OF SAID FLUID SYSTEM AT A RATE FROM ABOUT 10 TO ABOUT 55 GALLONS PER MINUTE PER SQUARE FOOT OF FILTER MEDIA SURFACE AREA TO REMOVE OILFREE PARTICULATE SOLIDS FROM SAID FILTER MEDIA.

Claim 13

A method for treating a fluid system containing oil and water to produce clarified water and oil which comprises: A. filtering said fluid system through a finely divided oil and water insoluble filter media containing from about 2 to about 8 cubic feet of filter material for each square foot of filter media surface area, at a flow rate from about 10 to about 35 gallons per minute per square foot of filter media surface area to retain oil within the filter media and pass an effluent selected from the group consisting of: clarified water and a mixture of oil and water which separates into defined layers of oil and clarified water, said mixture being attained when the oil content of the fluid system is in excess of about 1% by weight, said filter media having: i. a minimum particle mesh size within the range from about 3 to about 30 and a maximum particle mesh size within the range from about 30 to about 100 with the range between said minimum and maximum particle mesh sizes being at least about 20 mesh, ii. a median particle mesh size, by weight, which is a function of the API Gravity value of the oil, said median particle mesh size falling within the range defined by maximum and minimum linear values which vary directly with the linear value of said API Gravity, said median mesh size maximum linear value varying from about 18 to 62 and said median mesh size minimum linear value varying from about 10 to 54 as said API Gravity value varies from about 11 to 70, and iii. a particle size distribution pattern extending from the minimum particle mesh size to the maximum particle mesh size characterized in that the weight of the filter media substantially uniformly and progressively increases from: a. about 0 to 50 weight percent as the filter media particle mesh size varies from the minimum particle mesh size to the median particle mesh size, and b. about 0 to 50 weight percent as the filter media particle mesh size varies from the maximum particle mesh size to the median particle mesh size; and B. periodically regenerating the filter media by: passing an oil stripping composition through said filter media in the same direction of flow as that of the fluid system to remove oil from the filter media, and thereafter backwashing said filter media in a direction countercurrent to the flow of said fluid system at a rate from about 10 to about 35 gallons per minute per square foot of filter media surface area.

Claim 14

A method for treating a fluid system containing oil and water to produce clarified water and oil which comprises: A. filtering said fluid system through a finely divided oil and water insoluble filter media containing from about 2 to about 8 cubic feet of filter material for each square foot of filter media surface area, at a flow rate from about 10 to about 35 gallons per minute per square foot of filter media surface area to retain oil within the filter media and pass an effluent selected from the group consisting of: clarified water and a mixture of oil and water which separates into defined layers of oil and clarified water, said mixture being attained when the oil content of the fluid system is in excess of about 1% by weight, said filter media having: i. a minimum particle mesh size within the range from about 3 to about 30 and a maximum particle mesh size within the range from about 30 to about 100 with the range between said minimum and maximum particle mesh sizes being at least about 20 mesh, ii. a median particle mesh size, by weight, which is a function of the API Gravity value of the oil, said median particle mesh size falling within the range defined by maximum and minimum linear values which vary directly with the linear value of said API Gravity, said median mesh size maximum linear value varying from about 18 to 62 and said median mesh size minimum linear value varying from about 10 to 54 as said API Gravity value varies from about 11 to 70, and iii. a particle size distribution pattern extending from the minimum particle mesh size to the maximum particle mesh size characterized in that the weight of the filter media substantially uniformly and progressively increases from: a. about 0 to 50 weight percent as the filter media particle mesh size varies from the minimum particle mesh size to the median particle mesh size, and b. about 0 to 50 weight percent as the filter media particle mesh size varies from the maximum particle mesh size to the median particle mesh size; and B. periodically regenerating the filter media by: passing an oil stripping composition through said filter media in the same direction of flow as that of the fluid system to remove oil from the filter media, and thereafter backwashing said filter media in a direction countercurrent to the flow of said fluid system at a rate from about 10 to about 35 gallons per minute per square foot of filter media surface area.