Selectivation of adsorbents for gas separation

摘要

Systems and methods are provided for improving separation of gas phase streams using an adsorbent, such as 8-member ring zeolite adsorbents or DDR type zeolite adsorbents. Suitable gas phase streams can include at least one hydrocarbon, such as methane or a hydrocarbon containing at least one saturated carbon-carbon bond, and at least one additional component, such as CO2 or N2. The selectivity of the adsorbent is improved by selectivating the adsorbent with one or more barrier compounds. The presence of the barrier compounds is believed to alter the relative ability of potential adsorbates to enter into and/or move within the pores of the adsorbent.

主权项

1. A method for performing a gas separation, comprising:
contacting an adsorbent or membrane comprising an 8-member microporous material with a barrier compound under effective conditions to selectivate the adsorbent or membrane, the barrier compound having a minimum molecular dimension that is at least 0.4 Angstroms greater than the maximum dimension of the largest hard sphere that can diffuse along any direction of the adsorbent and a maximum dimension of about 25 Angstroms or less; wherein the effective conditions for contacting the adsorbent or membrane with a barrier compound comprise a temperature from about 50° C. to about 350° C. and a total pressure of about 100 psig (about 690 kPag) to about 2000 psig (about 13.8 MPag), wherein the barrier compound is present either as a liquid or as a gas with a partial pressure of the wherein compound that is at least about 10% of the saturation vapor pressure; wherein selectivation of the adsorbent or membrane comprises diffusion of at least one barrier compound molecule through a pores of the 8-member microporous material; contacting the selectivated adsorbent or membrane with an input gas stream containing a first component and a second component to form a first gas stream enriched in the first component relative to the input gas stream; and collecting a second gas stream enriched in the second component relative to the input gas stream.