| 摘要 |
<p>1536995 Adsorption process LINDE AG 3 Feb 1977 [4 Feb 1976] 04450/77 Heading B1L Two gases (e.g. CO and H) are separated by passing the mixture at elevated pressure (e.g. 20 bars) through two beds of adsorbent in series which preferentially adsorb one gas (CO) to deliver pure H from the second bed (stage I in Fig. 4), until the adsorption front reaches the upstream end of the second bed 2. The pressure is then reduced (stage II) while pure H is still withdrawn from bed 2, and at the lower pressure a second gas or gas mixture, whose partial pressure in CO exceeds that of the mixture to be separated, is fed to first bed 1, but this flow is stopped before any CO penetrates bed 2. The two beds are disconnected from each other (stage III), bed 1 being evacuated by pump 4 in the reverse direction to provide a flow of pure CO and bed 2 being reverse-flow flushed with H from stage II. The beds are reconnected (stage IV) and repressurised with H from stages II and possibly III, optionally in the reverse direction of flow. As shown some of the CO from stage III may be used as the second gas (mixture) in stage II. An optional stage I' may be included wherein a third gas mixture is fed through the beds, this mixture originating from bed 2 in stage III and having a greater partial pressure of CO than the mixture to be separated. Fig. 4 shows five two-bed systems operating in parallel, so that each system performs the sequence of stages, one stage out of phase with the next (Fig. 5 not shown). Each stage may last 5 minutes. The adsorbent may be zeolite, active carbon, silica gel, molecular filtration carbon. As described the process is applied to separating natural gas, from which water vapour and CO 2 have been first removed by conventional means. A small CH 4 fraction can be partly separated in stage II, wherein one component (H) emerges from bed 2 during pressure reduction while the CH 4 is retained by the bed until the second gas is fed into the beds.</p> |
