DEHYDRATION OF NATURAL GAS BY A MEMBRANE PROCESS

THE OBJECTIVE OF THE PROPOSED PROGRAM IS TO DEVELOP A MEMBRANE PROCESS FOR THE SEPARATION OF WATER FROM NATURAL GAS STREAMS. VIRTUALLY ALL NATURAL GAS PRODUCED MUST BE TREATED TO REMOVE WATER VAPOR PRIOR TO ENTERING THE PIPELINE. CURRENT DEHYDRATION TECHNIQUES ARE ENERGY-INTENSIVE AND ARE UNSUITED TO USE ON OFFSHORE OIL PLATFORMS BECAUSE OF THEIR BULK AND FIRE HAZARD. A MEMBRANEPROCESS WOULD BE COMPACT, USE LESS ENERGY AND ELIMINATE THE FIRE RISK. THE MEMBRANE PROCESS WE PROPOSE TO DEVELOP WOULD BE BASED ONCOMPOSITE MEMBRANES PREPARED WITH HYDROPHILIC RUBBERY MATERIALS AS THE PERMSELECTIVE LAYER. THE SELECTIVE MATERIALS OF CHOICE WILL HAVE A LOW PERMEABILITY FOR METHANE AND THE OTHER HYDROCARBONS IN NATURAL GAS, BUT WILL BE MUCH MORE PERMEABLE TO WATER. A TOUGH, SOLVENT-VAPOR RESISTANT POLYMER WILL BE USED TO PREPARE THE SUPPORT MEMBRANE. THE COMPOSITE MEMBRANES WILL BE TESTED WITH A PRESSURIZED SYNTHETIC NATURAL GAS MIXTURE CONTAINING WATER VAPOR. IN PRELIMINARY WORK, WE HAVE ALREADY FOUND A MEMBRANE THAT APPEARS TO BE CLOSE TO THE DESIRED PERMSELECTIVITY AND WE BELIEVE EVEN MORE SELECTIVE MEMBRANESCAN BE FORMED. AT THE END OF THE PHASE I PROGRAM, A SMALL SPIRAL-WOUND MEMBRANE MODULE WILL BE MADE AND TESTED. BASEDON THESE RESULTS, A PRELIMINARY TECHNICAL AND ECONOMIC ANALYSIS OF THE MEMBRANE DEHYDRATION PROCESS WILL BE PERFORMED.