Patent ID: 7361276

Claim:
A method of enhancing the concentration of a first inorganic compound in a first aqueous solution of a first process of a heavy chemical plant including an electrolyzer, said method comprising (a) feeding said first solution having said first compound at a first concentration and a first water vapor pressure to an osmotic membrane distillation means comprising a hydrophobic, gas and water vapor permeable membrane separating (i) a first chamber for receiving said first solution, from (ii) a second chamber for receiving a receiver feed aqueous solution having a second water vapor pressure lower than said first water vapor pressure; (b) feeding said receiver aqueous feed solution to said second chamber as to effect transfer of water vapor through said membrane from said first chamber to said second chamber, and to produce (i) a resultant first solution having a second concentration of said first compound greater than said first concentration and (ii) a diluted receiver feed aqueous solution; (c) collecting said resultant first solution; and (d) recycling at least a portion of one or both of said solutions selected from said resultant first solution and said diluted receiver feed aqueous solution within said heavy chemical plant to said electrolyzer.