Polyurethane oil de-emulsifcation unit

Abstract

A process for separating an aqueous emulsion including an aqueous phase and an non-aqueous phase into separated aqueous and non-aqueous phases, to provide a recovered non-aqueous phase, and to provide a recovered aqueous phase containing an acceptable level of the non-aqueous phase. In the process, at least one body, and preferably two or more bodies, of polymeric material, with a high surface area, typically a foam material or polymer chips, is used in a horizontal flow treatment system to break the emulsion and thus provide both the aqueous and non-aqueous phases as two separate flows. A wide range of polymers can be used in the system as the polymeric material including polyurethane, polypropylene, polystyrene, polyester, and polyethylene. If a very low level of non-aqueous phase in the effluent is required, for example to meet potable water standards, then a Kozlowski polyurethane, as described in U.S. Pat. No. 5,239,040 is preferred as the last polymeric material body.

1 . A process for separating an aqueous emulsion including an aqueous continuous phase and an non-aqueous disperse phase into separated aqueous and non-aqueous phases, to provide a recovered non-aqueous phase, and to provide a recovered aqueous phase containing an acceptable level of the non-aqueous phase, which process comprises:
 (a) contacting a flow of an aqueous emulsion with a first body of polymeric material having a high surface area;   (b) allowing the first body of polymeric material to become saturated with the non-aqueous phase of the emulsion;   (c) continuing the flow of aqueous emulsion until a separate non-aqueous phase is formed;   (d) separating the non-aqueous phase from the aqueous phase;   (e) recovering the separated non-aqueous phase;   (f) recovering a flow of treated aqueous phase; and   (g) if required, repeating steps (a) to (f) to contact the flow of treated aqueous phase with at least a second body of polymeric material having a high surface area until the acceptable level of non-aqueous material is reached in-the flow of recovered aqueous phase.   
   
   
       2 . A process according to  claim 1  wherein the polymer in the polymeric material is chosen from the group consisting of polyurethane, polypropylene, polystyrene, polyester, and polyethylene. 
   
   
       3 . A process according to  claim 2  wherein the polymer in the polymeric material is polyurethane. 
   
   
       4 . A process according to  claim 1  wherein the polymer material having a high surface area is in a form chosen from the group consisting of foam and high surface area chips. 
   
   
       5 . A process according to  claim 4  wherein the polymer material having a high surface area is a particulate polymeric foam material. 
   
   
       6 . A process according to  claim 1  wherein a plurality of bodies polymeric material is used, the flow contacts each of them in sequence, and separated non-aqueous phase is recovered from the flow after the each body of polymeric material. 
   
   
       7 . A process according to  claim 1  wherein a plurality of bodies polymeric material is used, the flow contacts each of them in sequence, and separated non-aqueous phase is recovered from the flow after the each body of polymeric material except for the last, and separated non-aqueous phase is recovered from the last body. 
   
   
       8 . A process according to  claim 1  wherein, when a sequence of bodies of polymeric materials is used, at least the last body of polyurethane material comprises a Kozlowski polyurethane. 
   
   
       9 . A process according to  claim 1  which further includes pretreatment steps prior to step (a) in which steps:
 (h) non-aqueous phase droplets large enough to coalesce are allowed to form a separated non-aqueous phase,   (i) the separated non-aqueous phase is recovered, and   (j) the aqueous phase-is recovered and used as the flow in step (a).