Kinetic fractionators, and cycling processes for fractionation of gas mixtures

摘要

A process for separating methane from a natural gas mixture employs pressure swing adsorption in one or more vessels. Each vessel has an adsorbent material having a kinetic selectivity for contaminants over methane greater than 5. Contaminants within the natural gas mixture become gases kinetically adsorbed within the adsorbent material. The vessel is placed under pressure to cause contaminants to be adsorbed in the surfaces and micro-pores of the adsorbent material. The process includes releasing a product stream comprised at least 95% by volume methane from a first gas outlet in the vessel, and desorbing the contaminant gases from the adsorbent material by reducing the pressure within the vessel. The desorbing step is done without applying heat to the vessel, thereby delivering a waste gas stream comprised at least 95% by volume of the contaminant gases. An improved fractionation vessel having both major and minor flow channels is also provided.

主权项

1. A process for separating methane from a natural gas mixture, the process comprising:
directing a natural gas mixture into a gas separation unit, the gas separation unit having at least one vessel comprised of:
a gas inlet for receiving the natural gas mixture,a first gas outlet,an adsorbent material that has a kinetic selectivity for contaminants over methane greater than 5, such that the contaminants become gases kinetically adsorbed within the adsorbent material,at least two major flow channels through the adsorbent material placing the gas inlet and the first gas outlet in fluid communication, andat least one minor flow channel through the adsorbent material, the minor flow channels being in fluid communication with the major flow channels; placing the at least one vessel under pressure to cause contaminants to be adsorbed to the adsorbent material; releasing a product stream comprised at least 95% by volume of methane from the first gas outlet; and desorbing the contaminant gases from the adsorbent material by reducing the pressure within the at least one vessel without applying heat to the vessel, thereby delivering a waste gas stream comprised at least 95% by volume of the contaminant gases.