| 摘要 |
The process is conducted in a circuit having first and second adsorbers and a product reservoir vessel, connected serially. The feedstock is a gas mixture containing contaminant and product components (for example, air containing N2 and O2). The process steps involved are: (1) feeding a charge of feed gas into the first adsorber, temporarily retaining it therein, and pressurizing it, so that the adsorbent adsorbs most of the contaminant component and purified product gas is produced; (2) co-currently depressurizing the first adsorber by discharging purified product gas through the second adsorber and reservoir vessel; (3) counter-currently venting both adsorbers; (4) partly re-pressurizing both the adsorbers with purified gas from the reservoir vessel; and then repeating steps (1-4) inclusive. The process includes the following advantages over PSA systems using parallel arranged adsorbers: reversal of product concentration gradient in the adsorbers is avoided; and co-current de-pressurization of the first adsorber to a very low level prior to counter-current venting is made possible, improving process efficiency.
|
