Patent ID: 7442231
Filing Date: 2008-10-28
Classification: B01D,F25J,Y02C

Abstract:
1. A process to purify a natural gas stream comprising between about 25% and about 60% total inerts, the process comprising the acts of: (a) treating the natural gas stream with a first-stage process comprising one or more processes of the group of selective membrane filtration, cryogenic distillation, and amine scrubbing to produce a semi-purified natural gas stream comprising less than or equal to about 30% total combined inerts; (b) treating the semi-purified natural gas stream with a second-stage process in a pressure swing adsorption unit having one or more adsorbent beds having CTS-1 molecular sieve to obtain a product natural-gas stream comprising less than about 5% total combined inerts; (c) recovering a low-BTU stream from either or both of the first-stage process or the second-stage process; (d) feeding the low-BTU stream to a gas-driven engine, the gas-driven engine being mechanically coupled to an electric generator; (e) generating electricity via the electric generator; and (f) using at least some of the generated electricity to power either or both of the first-stage process or the second-stage process.