Heat-reactivatable adsorbent gas fractionator and process

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.

Claim 29

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.

Claim 30

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.