A GAS-FIRED LIQUEFIER FOR NATURAL GAS RECOVERY FROM REMOTE LOCATIONS

THIS PROJECT CONSISTS OF A MOBILE, SELF-CONTAINED, GAS-FIREDNATURAL GAS LIQUEFIER SYSTEM FOR THE ECONOMIC RECOVERY OF NATURAL GAS FROM "CAPPED" WELLS IN REMOTE LOCATIONS. THE SYSTEM IS AN INNOVATIVE ARRANGEMENT OF MULTIPLE, TRUCK-MOUNTED STIRLING LIQUEFIER MODULES THAT LIQUEFY METHANE FOR RECOVERY FROM THE WELLHEAD GAS WHILE UTILIZING THE HEAVIER FRACTIONS OF THE NATURAL GAS FOR COMBUSTION TO POWER THE SYSTEM. BY DERIVING POWER FROM WELLHEAD GAS TO LIQUEFY METHANE, THE SYSTEM FACILITATES THE REFINEMENT AND TRANSPORT (BY TANK TRUCK) OF NATURAL GAS FROM WELL SITES FORWHICH PROVISION OF A PIPELINE AND ELECTRIC POWER OR DIESEL FUEL IS IMPRACTICAL. THE LIQUEFIER MODULE IS A COMPACT ARRANGEMENT WHEREIN A FOUR-CYLINDER, DOUBLE-ACTING SIEMENS-STIRLING ENGINE POWERED BY GAS COMBUSTION DRIVES A SECOND FOUR-CYLINDER, DOUBLE-ACTING SIEMENS-STIRLING CRYOREFRIGERATOR CAPABLE OF LIQUEFYING METHANE. THE ENGINE AND REFRIGERATOR ARE COUPLED BY A COMMON DRIVE LINKAGE THAT GIVES THE PISTONS OPTIMUM PHASING WITH STRAIGHT-LINE MOTION TO MINIMIZE SIDE FORCES AND WEAR. THE SYSTEM USES NONPOLLUTING HELIUM AS THE WORKING FLUID AND IS COOLED BY RECIRCULATING WATER. A SWITCHING RECUPERATIVE HEAT EXCHANGER IS USED TO PRECOOL THE WELLHEAD GAS AND SEPARATE OUT THE "HEAVY ENDS" FOR COMBUSTION PRIOR TO LIQUEFACTION OFTHE METHANE. THE PROTOTYPE DESIGN UNDER DEVELOPMENT IN PHASE I IS FOR A REFRIGERATION CAPACITY OF 4 KW AT 110 K TO LIQUEFY 16 KG OF METHANE PER HOUR. THIS UNIT WILL SERVE AS A SCALED-DOWN, TEST-BED PROTOTYPE FOR AN EVENTUAL 80 KW SIEMENS-STIRLING NATURAL GAS LIQUEFIER FOR FIELD APPLICATION.