Heat-reactivatable adsorbent gas fractionator and process
First Claim
1. In the process for removing a first gas from a mixture thereof with a second gas by flow of the gas mixture continuously through a sorbent bed having a preferential affinity for the first gas which includes the steps of passing the gas mixture in contact with and from one end to another end of a first bed of the sorbent;
- sorbing first gas thereon and, as the sorption of the first gas continues, forming a concentration gradient of first gas in the first bed progressively decreasing from one end to the other end of the bed ranging from a substantial proportion of the first sorbent capacity therefor at one end to less than 20% of its capacity therefor at the other end, so as to produce a gaseous effluent which has a concentration of the first gas therein below a predetermined maximum;
removing first gas sorbed on the second sorbent bed by passing a purge flow of effluent gas in contact with the sorbent bed, discontinuing the purge flow, and then resuming passing the gas mixture in contact with the sorbent bed, the improvement which consists essentially in utilizing a sorbent transparent to microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz, and combining with the sorbent a microwave absorbent capable of absorbing microwave energy within said range in an amount sufficient to activate and desorb sorbed first gas on the sorbent, and then desorbing first gas by applying during the purge flow microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz at a temperature at which the sorbent is transparent to microwave energy, the microwave energy being preferentially adsorbed by the microwave absorbent and then activating first gas sorbed on the sorbent and thereby desorbing first gas, and halting application of the microwave energy when desorption of first gas is substantially complete, and before water of hydration of the sorbent is removed.
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Accused Products
Abstract
A process and appartus are provided for removing a first gas from a mixture thereof with a second gas. The gas mixture is passed through a sorbent bed having a preferential affinity for the first gas and comprising a microwave absorbent capable of absorbing microwave energy and the first gas is sorbed on the sorbent so as to produce a gaseous effluent which has a concentration of first gas therein below a predetermined maximum. Then the first gas sorbed on the sorbent bed is removed therefrom by application of microwave energy, at a temperature at which the microwve absorbent absorbs such energy and activates the first gas sufficiently to desorb the first gas, while passing a purge flow of gas in contact with the bed to flush out desorbed first gas from the bed. The bed is allowed to cool to a relatively efficient temperature for adsorption. The gas mixture is then again passed in contact with the bed. If two beds are used, one bed can be desorbed while the other is on-stream, thereby maintaining a substantially continuous flow of effluent gas.
The apparatus of the invention provides a sorbent bed assembly having a microwave energy generator positioned to direct such energy into a sorbent bed comprising a microwave absorbent capable of absorbing microwave energy for desorption of first gas from the sorbent bed.
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Citations
33 Claims
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1. In the process for removing a first gas from a mixture thereof with a second gas by flow of the gas mixture continuously through a sorbent bed having a preferential affinity for the first gas which includes the steps of passing the gas mixture in contact with and from one end to another end of a first bed of the sorbent;
- sorbing first gas thereon and, as the sorption of the first gas continues, forming a concentration gradient of first gas in the first bed progressively decreasing from one end to the other end of the bed ranging from a substantial proportion of the first sorbent capacity therefor at one end to less than 20% of its capacity therefor at the other end, so as to produce a gaseous effluent which has a concentration of the first gas therein below a predetermined maximum;
removing first gas sorbed on the second sorbent bed by passing a purge flow of effluent gas in contact with the sorbent bed, discontinuing the purge flow, and then resuming passing the gas mixture in contact with the sorbent bed, the improvement which consists essentially in utilizing a sorbent transparent to microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz, and combining with the sorbent a microwave absorbent capable of absorbing microwave energy within said range in an amount sufficient to activate and desorb sorbed first gas on the sorbent, and then desorbing first gas by applying during the purge flow microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz at a temperature at which the sorbent is transparent to microwave energy, the microwave energy being preferentially adsorbed by the microwave absorbent and then activating first gas sorbed on the sorbent and thereby desorbing first gas, and halting application of the microwave energy when desorption of first gas is substantially complete, and before water of hydration of the sorbent is removed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12)
- sorbing first gas thereon and, as the sorption of the first gas continues, forming a concentration gradient of first gas in the first bed progressively decreasing from one end to the other end of the bed ranging from a substantial proportion of the first sorbent capacity therefor at one end to less than 20% of its capacity therefor at the other end, so as to produce a gaseous effluent which has a concentration of the first gas therein below a predetermined maximum;
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13. A process for reducing the concentration of a first gas in a mixture thereof with a second gas to below a limiting maximum concentration thereof in the second gas, which consists essentially in passing the mixture in contact with and from one end to another of a stationary bed of a sorbent having a preferential affinity for the first gas and transparent to microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz;
- and comprising a microwave absorbent capable of absorbing microwave energy within said range;
adsorbing first gas on the sorbent to form a gaseous effluent having a concentration thereof below the maximum, and as the adsorption continues forming a concentration gradient of first gas on the bed progressively decreasing from the one end to the other end, and an increasing concentration of first gas in the second gas defining a concentration front progressively advancing in the bed from the one end to the other end as sorbent capacity therefor decreases;
discontinuing passing the gaseous mixture in contact with the bed before the front can leave the bed, and the limiting maximum concentration of first gas in the second gas can be exceeded; and
then desorbing the first gas adsorbed on the sorbent bed by application of microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz at a temperature at which the microwave absorbent absorbs such energy and activates and thereby desorbs first gas adsorbed on the sorbent bed while passing therethrough a purge gas flow to flush desorbed first gas from the bed. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
- and comprising a microwave absorbent capable of absorbing microwave energy within said range;
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27. An apparatus for reducing the concentration of a first gas in a mixture thereof with a second gas to below a limiting maximum concentration thereof comprising, in combination, a stationary bed of sorbent having a preferential affinity for the first gas;
- and transparent to microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz; and
comprising a microwave absorbent capable of absorbing microwave energy within said range;
an inlet line for delivering influent gas at an inlet end of the bed; and
an outlet line for delivering effluent gas from an outlet end of the bed;
means for applying to the sorbent bed microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz for desorbing first gas from the bed at the conclusion of an adsorption cycle; and
means for supplying a flushing flow of purge gas during application of microwave energy to remove desorbed first gas from the bed. - View Dependent Claims (28, 29, 30, 31, 32, 33)
- and transparent to microwave energy having a frequency within the range of about 0.03 to about 3000 giga Hertz; and
Specification