Method and apparatus for membrane separation

A method of gas separation comprising the steps of:

• a) compressing an ambient air stream;
• b) cooling the compressed air stream;
• c) heating the air stream using a primary heater disposed downstream of the cooler;
• d) heating the air stream using a secondary heater disposed downstream of the primary heater;
• and,
• e) providing a permeable membrane gas separator downstream of the secondary heater having a permeate outlet and a non-permeate outlet;
• and
• f) controlling the secondary heater by averaging the output of first, second and third temperature sensors wherein said first temperature sensor is disposed between said secondary heater and said permeable membrane gas separator, wherein said second temperature sensor is disposed in said permeate outlet, wherein said third temperature sensor is disposed in said non-permeate outlets.

Apparatus for the production of nitrogen gas from compressed air, comprising:

• a) a compressor for compressing ambient air;
• b) a cooler connected to receive compressed air from said compressor for cooling the compressed air;
• a primary beater downstream of said cooler;
• d) a secondary heater downstream of said primary heater;
• e) a permeable membrane gas separator downstream of said secondary heater for separating out the nitrogen in the compressed air;
• and
• f) a programmable logic controller for controlling said secondary heater by averaging an output of first, second and third temperature sensors disposed respectively between said secondary heater and said permeable membrane gas separator, and in permeate and non-permeate outlets of said permeable membrane gas separator to maintain a desired set point temperature for said permeable membrane gas separator.