Patent ID: 7105038
Filing Date: 2006-09-12
Classification: B01D

Abstract:
1. A gas concentration method for separating a certain gas by applying a pressure difference to an adsorbent having an adsorption power selective for the gas, comprising: a first step of introducing a feed gas mixture through a supply port of a first adsorbent bed having a pressure lower than the feed gas mixture, adsorbing a more adsorbable component to an adsorbent in the first adsorbent bed while desorbing the adsorbed component from a second adsorbent bed by reducing the internal pressure of the second adsorbent bed, discharging a relatively less adsorbable component through a production port of the first adsorbent bed to produce an enriched gas and supplying a part of the enriched gas to a production port of the second adsorbent bed through a microtube connecting the production ports of the adsorbent beds; a second step of reducing the internal pressure of the first adsorbent bed from the supply port to desorb the adsorbed component and increasing the pressure inside the second adsorbent bed from a supply port by supplying the feed gas mixture through the supply port of the second adsorbent bed to adsorb the more adsorbable component, in which a pressure gradient existing between the production ports and the supply ports of the first and second adsorbent beds is such that the production port of the first adsorbent bed has a pressure higher than that of the production port of the second adsorbent bed, whereby a part of the product gas is supplied from the production port of the first adsorbent bed to the production port of the second adsorbent bed, and the product gas is continuously produced during this step with a moment when the enriched gas is simultaneously produced from the production ports of the first adsorbent bed and the second adsorbent bed; a third step of reversing the pressure gradient between the production port of the first adsorbent bed and the production port of the second adsorbent bed in the second step so that the first adsorbent bed undergoes the desorption and the second adsorbent bed undergoes the adsorption, contrary to the first step, and discharging the enriched gas from the production port of the second adsorbent bed while supplying a part of the enriched gas produced from the production port of the second adsorbent bed to the production port of the first adsorbent bed; and a fourth step of supplying a part of the product gas from the production port of the second adsorbent bed to the production port of the first adsorbent bed by the pressure gradient between the adsorbent beds, contrary to the second step, increasing the pressure inside the first adsorbent bed from the supply port by supplying the feed gas mixture through the supply port to carry out the adsorption, reducing the pressure inside the second adsorbent bed from the supply port to carry out the desorption, in which the product gas is continuously produced during this step with a moment when the enriched gas is simultaneously produced from the production ports of the first adsorbent bed and the second adsorbent bed; and wherein a suction pressure by a gas discharger is always lower on at least one of the supply ports than on another supply port, whereby the gas is continuously produced.