Multistage system for separating gas by adsorption

A method of separating components of a feed gas mixture comprising the steps of:

• providing a first adsorbent module including at least one first adsorbent bed of a first adsorbent material;
• providing a second adsorbent module in communication with the first adsorbent module, the second adsorbent module including at least one second adsorbent bed of a second adsorbent material;
• adsorbing a feed gas mixture component from the feed gas mixture with the first adsorbent material;
• transferring a first product gas from between the first adsorbent module and the second adsorbent module, the first product gas substantially depleted in the adsorbed feed gas mixture component;
• adsorbing a first product gas component from the first product gas with the second adsorbent material, and
• extracting a second product gas from the second adsorbent module, the second product gas substantially depleted in the adsorbed first product gas component;
• wherein the adsorbent modules comprise pressure swing adsorbent modules, and the step of extracting a second product gas comprises the steps of extracting pressurized light reflux gas from the second adsorbent module, and returning the light reflux gas to the second adsorbent module after pressure letdown.

A gas separation system comprising:

• a first adsorbent module including a first feed gas inlet for receiving a feed gas mixture, at least one first adsorbent bed of first adsorbent material in communication with the first feed gas inlet for adsorbing a gas mixture component from the feed gas mixture, and a first gas outlet in communication with the at least one first adsorbent bed for receiving a first product gas therefrom, the first product gas substantially depleted in the adsorbed feed gas mixture component;
• a second adsorbent module including a second gas inlet fluidly connected to the first gas outlet for receiving the first product gas, at least one second adsorbent bed of second adsorbent material in communication with the second gas inlet for adsorbing a first product gas component from the first product gas, and a second gas outlet in communication with the at least one second adsorbent bed for receiving a second product gas therefrom, the second product gas substantially depleted in the adsorbed first product gas component, the first and second adsorbent modules being configured for transferring the first product gas between the adsorbent modules;
• and
• wherein the adsorbent modules comprise pressure swing gas adsorbent modules, the second gas adsorbent module includes a heavy reflux gas outlet for providing heavy reflux gas, a reflux compressor in communication with the heavy reflux gas outlet for compressing the heavy reflux gas, and a heavy reflux gas inlet for receiving the pressurized heavy reflux gas from the reflux compressor.

A method of separating components of a feed gas mixture comprising the steps of:

• providing a first adsorbent module including at least one first adsorbent bed of a first adsorbent material;
• providing a second adsorbent module in communication with the first adsorbent module, the second adsorbent module including at least one second adsorbent bed of a second adsorbent material;
• adsorbing a feed gas mixture component from the feed gas mixture with the first adsorbent material;
• transferring a first product gas from between the first adsorbent module and the second adsorbent module, the first product gas substantially depleted in the adsorbed feed gas mixture component;
• adsorbing a first product gas component from the first product gas with the second adsorbent material, and
• extracting a second product gas from the second adsorbent module, the second product gas substantially depleted in the adsorbed first product gas component;
• wherein the adsorbent modules comprise pressure swing adsorbent modules, and the step of extracting a second product gas comprises the steps of extracting heavy reflux gas from the second adsorbent module, and returning the heavy reflux gas to the second adsorbent module under increased pressure.