Carbon Molecular Sieve
Nitrogen generation by Pressure Swing Adsorption (PSA) process is a technology used to separate nitrogen from a mixture of gases under pressure according to the special selective adsorption characteristics of the Carbon Molecular Sieves (CMS).
The Carbon molecular sieve is a material containing tiny pores of a precise and uniform size that is used as an adsorbent for gases. When the pressure is high enough, the oxygen molecules, which pass through the pores of CMS much faster than the nitrogen molecules, are adsorbed, while the coming out nitrogen molecules will be enriched in gas phase. The enriched oxygen air, adsorbed by the CMS, will be released by reducing the pressure. Then the CMS is regenerated and ready for another cycle of producing nitrogen enriched air.
Quality Indicator of the CMS:
1. the diameter of the CMS granule 1.7—1.8mm
2. the period of adsorption 120S
3. the bulk density 680～700g/L
4. the compressive strength ≥ 95N/ granule
5. the performance of the CMS as following Table ONE.
Specifications
| Type |
Adsorbent pressure |
Nitrogen concentration |
Nitrogen quantity |
N2/Air |
| (MPa) |
(N2%) |
(NM3/h.t) |
(%) |
| CMS-160 |
0.8 |
99.99 |
40 |
15 |
| 99.9 |
100 |
23 |
| 99.5 |
160 |
34 |
| 99 |
200 |
38 |
| 98 |
290 |
43 |
| CMS-185 |
0.8 |
99.99 |
60 |
20 |
| 99.9 |
120 |
26 |
| 99.5 |
185 |
36 |
| 99 |
230 |
41 |
| 98 |
310 |
46 |
| CMS-200 |
0.8 |
99.99 |
70 |
21 |
| 99.9 |
140 |
27 |
| 99.5 |
200 |
36 |
| 99 |
260 |
41 |
| 98 |
330 |
48 |
| CMS-220 |
0.8 |
99.99 |
90 |
25 |
| 99.9 |
160 |
34 |
| 99.5 |
220 |
43 |
| 99 |
290 |
48 |
| 98 |
360 |
54 |
| CMS-240 |
0.8 |
99.99 |
100 |
26 |
| 99.9 |
175 |
35 |
| 99.5 |
240 |
44 |
| 99 |
300 |
49 |
| 98 |
370 |
55 |
| CMS-260 |
0.8 |
99.99 |
110 |
27 |
| 99.9 |
190 |
36 |
| 99.5 |
260 |
45 |
| 99 |
310 |
50 |
| 98 |
380 |
56 |
PSA Nitrogen Generation Process
1. Air Feed System
The environmental air supplied to the PSA system should be compressed and purified to get rid of the dust, the oil and water.
2. PSA Nitrogen Generation System
While the compressed and purified air flows through the adsorbent bed with CMS inside in a bottom up way under the pressure of 0.6MPa, the oxygen molecules will be adsorbed by the solid surfaces of the CMS, and the enriched nitrogen will be output from the top of the bed to the container.
When the adsorbent bed reaches the end of its capacity to adsorb oxygen, it can be regenerated by reducing the pressure, thereby releasing the adsorbed oxygen. Using two adsorbent beds to absorb and regenerate in turn allows to produce continuous nitrogen in cycle.
