VPSA vs PSA
Every oxygen production technology serves a niche in the global supply of oxygen. The single most important factor in determining which production technology offers the ideal economics in your situation is the quantity of oxygen that you need. At and below 3 Tons Per Day (TPD), oxygen PSA or Liquid Oxygen (LOX) will most likely represent your low cost solution. From 3 TPD to 5 TPD there is a real battle zone between oxygen PSA and oxygen VPSA. Over 5 TPD it is very hard for the PSA power cost to prevail over VPSA technologies. And as the chart above shows, not all VPSA suppliers are the same.
For the 3 to 5 TPD battle zone oxygen demand cases, here are additional PSA and VPSA differences that you should consider in your decision making.
| Oxygen PSA and EcoGen™ VPSA Differences | ||
|---|---|---|
| Item | Adsorptech EcoGen™ VPSA | PSA |
| Capital | Initial looks higher ... but | Initial looks lower ... but |
| Major Components | Skid & O2 Buffer | Air Compressor, Air Dryer, Oil Removal Equipment, Vessel/Valve Skid, 2 Buffers, Electrical Starters, Electrical Distribution, Central Control |
| Power | Base | 2 times more & power rates compound over time |
| Switching Valves | 3 | 6 |
| Electrical Connections | 1 | 3 |
| Buyer Scope | ||
| Building | Not Required | Required |
| Interconnecting Piping | None | Between all components |
| Interconnecting Controls | None | Between all components |
| Interconnecting Electrical | None | Between all components |
| Installation | Simpler - 2 parts | Complex - 6 major parts |
| Relocation | Simpler - 2 parts | Complex - 6 major parts |
| Foundation | One Simple | Multiple or larger |
| Oily Condensate Removal & Drain | Not Required | Required, perhaps oily |
| Buyer Impact | ||
| Process Pressures | Low | High |
| Power Turndown | Up to 70% | Up to 30% |
| Built in Redundancy | Yes | No |
| Operating Purity Flexibility | 85% to 95% capable | 90% +/- 3% |
| Cold Temperature Operating Limit | Good to -40 °F (-40 °C) | Must be above freezing |
| Maintenance | Base | Higher & costs compound |
| Sieve Changes | None expected | Every 3 to 5 years $ costs compound |
| Cooling Water | None | Required on air compression |
| Drain Permitting | None | Required, possibly oily condensate |
| Yet some oxygen PSA economics at & below 2 to 3 stpd do appear better than most VPSA systems | ||