Process for separating kinetic hydrate polymer inhibitors

Abstract

Process for separating kinetic hydrate inhibitor polymers having a molecular weight of at least 1000 Da from an aqueous mixture further comprising hydrocarbons and salts which process comprises contacting the aqueous mixture with the feed side of a membrane having an average pore diameter of from 0.7 to 4 nm, and obtaining at the permeate side of the membrane an aqueous permeate of which the concentration of kinetic hydrate inhibitor polymer is at most 20% of that of the aqueous mixture.

1 . A process for separating kinetic hydrate inhibitor polymer having a molecular weight of at least 1000 Da from an aqueous mixture further comprising hydrocarbons and salts which process comprises contacting the aqueous mixture with the feed side of a membrane having an average pore diameter of from 0.7 to 4 nm, and obtaining at the permeate side of the membrane an aqueous permeate of which the concentration of kinetic hydrate inhibitor polymer is at most 20% of the kinetic hydrate inhibitor polymer concentration of the aqueous mixture. 
     
     
         2 . A process according to  claim 1 , wherein the membrane is a ceramic membrane having a pore diameter of from 0.9 to 3 nm. 
     
     
         3 . A process according to  claim 2 , wherein the kinetic hydrate inhibitor polymer has a molecular weight of at least 1500 Da. 
     
     
         4 . A process according to  claim 1 , wherein the kinetic hydrate inhibitor polymer is chosen from the group consisting of homopolymers and copolymers containing amide groups. 
     
     
         5 . A process according to  claim 1 , wherein the temperature of the aqueous mixture is at most 90° C. 
     
     
         6 . A process according to  claim 1 , wherein the aqueous mixture comprises liquid natural gas condensate. 
     
     
         7 . A process according to  claim 1 , wherein the kinetic hydrate inhibitor polymer is a dendrimeric compound.) 
     
     
         8 . A process, comprising:
 (a) adding a kinetic hydrate inhibitor polymer having a molecular weight of at least 1000 Da to raw natural gas to provide a mixture,   (b) sending the mixture obtained in step (a) to a slug-catcher, and   (c) separating kinetic hydrate inhibitor polymer from at least part of the product of step (b) in a process according to  claim 1 .