APPLICABILITY OF THE JOULE - THOMSON CRYOCOOLER COUPLED WITH MEMBRANE -BASED PURIFICATION SYSTEM FOR LIQUEFACTION OF NATURAL GAS IN SMALL QUANTITIES

摘要

Joule -^sThomson (J-T) cryocoolers using gas mixture have been studied theoretically and experimentally for a variety of applications Gas separation technology using polymer membrane is emerging. In this paper the concept of coupling the J-T cooler with a hollow fiber membranes is presented The apparatus can be used in many applications, like compressed natural gas (CNG) purification and condensation into LNG or separation and liquefaction of nitrogen from air The paper describes the system and experimental dependence of the separated nitrogen purity on the membrane inlet air pressure The Second Law of Thermodynamics is used to optimize the composition of the mixture for natural gas cooling and liquefaction Possible applications of the system depend on membrane material Membranes used in separation of N2/air or CO2/CH4 are now commercially available [2,6] The combination of the J-T cooler with N2/air membrane enables the construction of the liquid nitrogen production system aimed at cryosurgical applications Similarly, J-T cooler coupled with CO2/CH4 membrane can be used for purification and liquefaction of natural gas in small quantities e g. satisfying future car refueling system needs.