Processes and apparatuses for reducing molecular weight fluctuation in a tail gas stream from a pressure swing adsorption process
AssigneeUop LLC
InventorsAnh Ngo, Shubhra J. Bhadra, Garrett Lukin, William Cady, Nasser Khazeni
Life of this patent
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Abstract
Processes and apparatuses for reducing molecular weight fluctuation in a tail gas stream from a pressure swing adsorption process. Multiple PSA separation zone are synchronized such that when one of the PSA units is generating a low molecular weight tail gas, there is another PSA unit generating a high molecular weight tail gas.
Claims20
A method for reducing molecular weight fluctuation in a tail gas stream from a pressure swing adsorption process, the method comprising:
- providing a first PSA separation zone comprising a plurality of vessels each containing an adsorbent configured to adsorb a species from a multi-component feed and provide a product stream, and a first tail gas stream by cycling through a first plurality of steps, wherein a molecular weight of the first tail gas stream fluctuates between a relatively high molecular weight and a relatively low molecular weight;
- providing a second PSA separation zone a second plurality of vessels each containing an adsorbent configured to adsorb a species from a multi-component feed and provide a product stream, and a second tail gas stream by cycling through a second plurality of steps, wherein a molecular weight of the second tail gas stream fluctuates between a relatively high molecular weight and a relatively low molecular weight;
- synchronizing the first plurality of steps with the second plurality of steps so that when the first tail gas stream has the high molecular weight, the second tail gas stream has the low molecular weight.
A method for reducing molecular weight fluctuation in a tail gas stream from a pressure swing adsorption process, the method comprising:
- operating a plurality of PSA separation zones to adsorb a species from a multi-component feed, wherein each PSA separation zone comprises a plurality of vessels each containing an adsorbent configured by cycling through a plurality of steps, wherein each PSA separation zone provides a product stream and a tail gas stream, and wherein a molecular weight of each tail gas stream fluctuates between a relatively high molecular weight and a relatively low molecular weight;
- combining the tail gas streams from each PSA separation zone to form a net tail gas stream;
- and
- controlling each PSA separation zone such that when a tail gas stream from a first PSA separation zone has the high molecular weight, a tail gas stream from a second PSA separation zone has the low molecular weight.
A method for reducing molecular weight fluctuation in a tail gas stream from a pressure swing adsorption process, the method comprising:
- operating a plurality of PSA separation zones to adsorb a species from a multi-component feed, wherein each PSA separation zone comprises a plurality of vessels each containing an adsorbent configured by cycling through a plurality of steps, wherein each PSA separation zone provides a product stream and a tail gas stream, and wherein a molecular weight of each tail gas stream fluctuates between a relatively high molecular weight and a relatively low molecular weight, and wherein the plurality of steps comprise:
- an adsorption step, a co-current depressurization step, a counter-current depressurization step, a purge step, and a repressurization step;
- combining the tail gas streams from each PSA separation zone to form a net tail gas stream;
- and
- controlling each PSA separation zone such that when a tail gas stream from a first PSA separation zone has the high molecular weight, a tail gas stream from a second PSA separation zone has the low molecular weight, and when the tail gas stream from the first PSA separation zone has the low molecular weight, the tail gas stream from the second PSA separation zone has the high molecular weight.
Dependencies are inferred from the claim text.