Patent ID: 9138688
Filing Date: 2015-09-22
Classification: B01D,C02F,Y10T

Abstract:
1. A method for treating produced water for steam generation, the method comprising: providing a source of produced water to be treated, the water having contaminants selected from the group of total organic content (“TOC”) and total dissolved solids (“TDS”) as silica and hardness ions; removing at least a portion of the silica and hardness ions as suspended solids by subjecting the produced water to an electrocoagulation process; removing at least a substantial portion of the suspended solids in a polymer filtration unit, the filtration unit operating at a temperature of at least about 50 degrees Centigrade; lowering the water temperature of the produced water; further treating the produced water within the filtration unit, further wherein the filtration unit comprises at least one membrane selected from the following: polyethersulfone (PES) membrane, polyacrylonitrile (PAN) membrane, polyvinylidene difluoride (PVDF) membrane, sulfonated polyether ether ketone (PEEK) membrane, Nafion membranes (sulfonated tetrafluoroethylene based fluoropolymer-copolymer), poly(phthalazinone ether sulfone) membrane (PPES), poly(phthalazinone ether ketone) membrane (PPEK), poly(phthalazinone ether fulfone ketone) membrane (PPESK); generating a pre-treated water; passing the pre-treated water to a forward osmosis (FO) unit employing a draw solution selected comprising at least one of polyvalent osmotic ions, monovalent osmotic ions and combinations thereof; subsequently treating the pre-treated water in a direct contact membrane distillation (DCMD) unit, wherein the DCMD unit employs a composite membrane comprising a hydrophilic polymer layer and a hydrophobic polymer layer.