Table 4 Optimization results for PSA and PVSA cycles using LiX and LiLSX zeolites with maximum oxygen recovery, and varying minimum oxygen purity and production levels.
From: Flexible oxygen concentrators for medical applications
Parameter/output metric | Unit | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 5 L/min | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 10 L/min | ||||
|---|---|---|---|---|---|---|---|
\(P_{{\mathrm{O}}_{2}}\) \(\ge\) 70% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 75% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 80% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 70% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 75% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 80% | ||
PSA cycle with LiX adsorbent | |||||||
\(\hbox {O}_{2}\) purity | % | 69.96 | 74.99 | 79.93 | 69.98 | 75.09 | - |
\(\hbox {O}_{2}\) recovery | % | 60.40 | 53.81 | 43.46 | 61.05 | 50.54 | - |
\(\hbox {O}_{2}\) production | L min\(^{-1}\) | 10.92 | 16.54 | 9.58 | 17.11 | 10.54 | - |
Bed size factor | kg ads. \(\hbox {O}_{2}\) TPD\(^{-1}\) | 33.24 | 22.87 | 39.49 | 22.11 | 32.24 | – |
\(P_1\) | bar | 3.5 | 3.5 | 3.5 | 3.5 | 3.5 | – |
\(P_2\) | bar | 1 | 1 | 1 | 1 | 1 | – |
\(P_3\) | bar | 1 | 1 | 1 | 1 | 1 | – |
\(t_1\) | s | 4.7 | 3.8 | 4.7 | 4.2 | 3.8 | – |
\(t_2\) | s | 1 | 1 | 1 | 1 | 1 | – |
\(t_3\) | s | 5.9 | 1.9 | 4.5 | 2.1 | 4.5 | – |
\(t_4\) | s | 1 | 1 | 1 | 1 | 1 | – |
\(\dot{n}_1\) | mol s\(^{-1}\) | 0.17 | 0.22 | 0.19 | 0.2 | 0.2 | – |
Purge flow velocity factor | - | 0.46 | 1.34 | 0.78 | 1.19 | 0.54 | – |
\(\rho _{b,ads}\) | kg ads. m\(^{-3}\) bed | 748.6 | 780 | 780 | 780 | 700.66 | – |
Parameter/output metric | Unit | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 5 L/min | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 10 L/min | ||||
|---|---|---|---|---|---|---|---|
\(P_{{\mathrm{O}}_{2}}\) \(\ge\) 80% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 85% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 90% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 80% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 85% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 90% | ||
PVSA cycle with LiX adsorbent | |||||||
\(\hbox {O}_{2}\) purity | % | 79.9 | 84.99 | 90.03 | 79.7 | 84.93 | 90.03 |
\(\hbox {O}_{2}\) recovery | % | 81.23 | 76.8 | 61.18 | 81.21 | 73.25 | 59.24 |
\(\hbox {O}_{2}\) production | L min\(^{-1}\) | 14.12 | 14.25 | 11.99 | 13.92 | 12.31 | 10.62 |
Bed size factor | kg ads. \(\hbox {O}_{2}\) TPD\(^{-1}\) | 21.56 | 25.42 | 27.7 | 21.46 | 23.89 | 28.76 |
\(P_1\) | bar | 3.49 | 3.5 | 3.5 | 3.5 | 3.5 | 3.5 |
\(P_2\) | bar | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
\(P_3\) | bar | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 |
\(t_1\) | s | 6.2 | 6.6 | 6.2 | 6.1 | 5 | 6.2 |
\(t_2\) | s | 1 | 1 | 1 | 1 | 1 | 1 |
\(t_3\) | s | 5.9 | 6.8 | 5.7 | 5.9 | 7.4 | 5.9 |
\(t_4\) | s | 1 | 1 | 1 | 1 | 1 | 1 |
\(\dot{n}_1\) | mol s\(^{-1}\) | 0.14 | 0.15 | 0.16 | 0.14 | 0.17 | 0.14 |
Purge flow velocity factor | – | 0.53 | 0.6 | 0.9 | 0.49 | 0.43 | 0.86 |
\(\rho _{b,ads}\) | kg ads. m\(^{-3}\) bed | 627.72 | 747.02 | 684.89 | 616.06 | 606.55 | 629.81 |
Parameter/output metric | Unit | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 5 L/min | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 10 L/min | ||||
|---|---|---|---|---|---|---|---|
\(P_{{\mathrm{O}}_{2}}\) \(\ge\) 75% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 80% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 85% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 75% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 80% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 85% | ||
PSA cycle with LiLSX adsorbent | |||||||
\(\hbox {O}_{2}\) purity | % | 74.89 | 79.99 | 84.72 | 74.94 | 80 | – |
\(\hbox {O}_{2}\) recovery | % | 55.46 | 45.32 | 30.14 | 55.56 | 45.45 | – |
\(\hbox {O}_{2}\) production | L min\(^{-1}\) | 16.9 | 14.53 | 9.02 | 14.69 | 12.35 | – |
Bed size factor | kg ads. \(\hbox {O}_{2}\) TPD\(^{-1}\) | 19.27 | 22.44 | 36.15 | 22.2 | 26.42 | – |
\(P_1\) | bar | 3.49 | 3.5 | 3.49 | 3.49 | 3.5 | – |
\(P_2\) | bar | 1 | 1 | 1 | 1 | 1 | – |
\(P_3\) | bar | 1 | 1 | 1 | 1 | 1 | – |
\(t_1\) | s | 2.7 | 2.5 | 3 | 3.6 | 3.4 | – |
\(t_2\) | s | 1 | 1 | 1 | 1 | 1 | – |
\(t_3\) | s | 1 | 1 | 1.4 | 1 | 1 | – |
\(t_4\) | s | 1 | 1 | 1 | 1 | 1 | – |
\(\dot{n}_1\) | mol s\(^{-1}\) | 0.23 | 0.25 | 0.23 | 0.17 | 0.18 | – |
Purge flow velocity factor | – | 1.83 | 1.9 | 1.97 | 2.44 | 2.5 | – |
\(\rho _{b,ads}\) | kg ads. m\(^{-3}\) bed | 671.57 | 672.6 | 672.75 | 672.38 | 672.75 | – |
Parameter/output metric | Unit | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 5 L/min | \(PC_{{\mathrm{O}}_{2}}\) \(\ge\) 10 L/min | ||||
|---|---|---|---|---|---|---|---|
\(P_{{\mathrm{O}}_{2}}\) \(\ge\) 85% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 90% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 95% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 85% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 90% | \(P_{{\mathrm{O}}_{2}}\) \(\ge\) 95% | ||
PVSA cycle with LiLSX adsorbent | |||||||
\(\hbox {O}_{2}\) purity | % | 85.05 | 89.97 | 95 | 85 | 90 | – |
\(\hbox {O}_{2}\) recovery | % | 77.22 | 65.51 | 29.37 | 78.32 | 64.89 | – |
\(\hbox {O}_{2}\) production | L min\(^{-1}\) | 26.8 | 22.53 | 9.67 | 27.5 | 21.67 | – |
Bed size factor | kg ads. \(\hbox {O}_{2}\) TPD\(^{-1}\) | 12.15 | 14.48 | 30.07 | 11.86 | 15.05 | – |
\(P_1\) | bar | 3.5 | 3.5 | 3.5 | 3.5 | 3.5 | – |
\(P_2\) | bar | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | – |
\(P_3\) | bar | 0.5 | 0.5 | 0.5 | 0.5 | 0.5 | – |
\(t_1\) | s | 3 | 3.2 | 2.8 | 3.2 | 3.2 | – |
\(t_2\) | s | 1 | 1 | 1 | 1 | 1 | – |
\(t_3\) | s | 1.1 | 1.3 | 1.2 | 1 | 1.4 | – |
\(t_4\) | s | 1 | 1 | 1 | 1 | 1 | – |
\(\dot{n}_1\) | mol s\(^{-1}\) | 0.25 | 0.25 | 0.25 | 0.24 | 0.24 | – |
Purge flow velocity factor | – | 1.87 | 2.32 | 2.65 | 2.45 | 2.05 | – |
\(\rho _{b,ads}\) | kg ads. m\(^{-3}\) bed | 671.26 | 672.75 | 599.69 | 672.75 | 672.75 | – |
