What is a PSA oxygen generator?

PSA stands for Pressure Swing Adsorption. A PSA oxygen generator produces concentrated oxygen on-site from ambient air, using a pair of vessels filled with molecular-sieve material that selectively adsorbs nitrogen at higher pressure and releases it at lower pressure. The vessels cycle continuously, delivering a steady oxygen-rich stream — typically 93–95% O₂.

Why do ozone generators use oxygen feed gas?

Running an ozone generator on concentrated oxygen rather than ambient air dramatically increases efficiency: ozone output concentration rises from roughly 1–3 wt% (air-fed) to 8–14 wt% (oxygen-fed), and the energy cost per kilogram of ozone drops accordingly. Higher concentration also means a smaller contactor and less off-gas to manage.

What oxygen purity is needed for ozone generation?

Industrial ozone generators are designed to run on oxygen at about 90–95% purity, which is exactly what a well-sized PSA unit delivers. Gas dryness matters more than the last few percent of purity — incoming gas must be very dry (typically dewpoint below −60 °C) to protect the generator dielectrics.

Is on-site oxygen cheaper than bottled oxygen?

For continuous industrial use the answer is normally yes. On-site PSA removes the cost of trucked liquid oxygen or bottle hire / changeover, and removes the supply-risk that comes with depending on a delivery schedule. Payback depends on the size of the system and how much oxygen it uses — we can model it as part of the design phase.

What maintenance does a PSA oxygen generator need?

PSA is a proven low-maintenance technology. Typical service items are periodic inspection or top-up of the molecular-sieve material, routine valve servicing, replacement of inlet air filters, and checks on the compressor and dryer feeding the unit. Service is normally scheduled annually for continuous-duty systems.

Can PSA oxygen generators support aquaculture or industrial processes?

Yes. The same PSA technology that feeds an ozone generator can supply oxygen for direct oxygenation of recirculating aquaculture (RAS) and hatchery water, or for industrial processes that need a steady oxygen supply. See our aquaculture page for ozone + oxygen integration in fish systems.

Ozone Technologies Ltd

PSA Oxygen Generators NZ

Name: Ozone Technologies Ltd
Address: 22B Turner Place, Onekawa, Napier, Hawke's Bay, 4110, NZ
Telephone: +64 6 8432881
Price range: $$$$

On-site Pressure Swing Adsorption oxygen generation — integrated with ozone systems

Almost every industrial-scale ozone system needs concentrated oxygen as the feed gas — typically 93–95% O₂ — and the most cost-effective way to supply it is to generate it on site using Pressure Swing Adsorption (PSA). PSA is a proven, low-maintenance technology that produces oxygen from ambient air using a pair of molecular-sieve vessels switching between adsorption and desorption phases. Ozone Technologies Ltd supplies PSA oxygen generators in capacities from 1 Nm³/h to over 100 Nm³/h, designed and selected to match the ozone generator they will feed — and installed and commissioned as a single integrated system.

How PSA oxygen generation works

Ambient air is approximately 78% nitrogen, 21% oxygen and 1% other gases (mostly argon). PSA systems exploit the fact that zeolite molecular sieves preferentially adsorb nitrogen at elevated pressure. Compressed air passes through one of two vessels containing molecular sieve; nitrogen is adsorbed; oxygen passes through to a buffer tank at 93–95% concentration. Once the vessel is saturated, the system swings to the second vessel and the first is depressurised, releasing the adsorbed nitrogen back to atmosphere. This swing happens every 30–60 seconds in a continuous cycle. The result is a steady, on-demand supply of high-concentration oxygen with no consumable except compressed air and electricity.

Why PSA beats the alternatives

There are three ways to supply oxygen to an ozone generator: cylinder gas, liquid oxygen (LOX), or on-site PSA. Cylinder gas is acceptable for very small lab-scale ozone systems but uneconomic at any meaningful capacity — and the logistics of changing cylinders in a 24/7 operation are impractical. LOX requires a vacuum-insulated bulk storage tank, regular tanker deliveries, vapouriser controls and supply contracts; it makes sense at very high capacities (>2,000 Nm³/h equivalent) but for most industrial NZ applications the total cost of ownership is significantly higher than PSA. PSA is the sweet spot for the 1–100 Nm³/h range that covers most ozone installations: no deliveries, no contracts, no consumable beyond electricity, typically 5-year payback against LOX, and 10-year payback against cylinder gas.

PSA system components

A complete PSA package supplied by us includes: an oil-free or oil-removed compressed air supply (with redundancy options); refrigerated air dryer to remove water vapour; particulate and oil-coalescing filters; air receiver tank; the PSA module itself (twin molecular-sieve vessels with automatic switching valves); oxygen buffer tank; oxygen purity analyser with low-purity alarm and ozone-generator interlock; flow and pressure instrumentation; PLC control with HMI; and full SCADA integration. We size the compressed-air system, the PSA module and the buffer tank as a matched set — getting any one of them wrong destabilises the entire ozone system downstream. We also specify the molecular-sieve charge with appropriate over-sizing for the New Zealand climate (high humidity in coastal locations places extra demand on the air dryer).

Applications beyond ozone

While most of our PSA systems feed ozone generators, the same technology serves many other industrial applications in New Zealand. Aquaculture facilities use PSA oxygen directly for water oxygenation in high-density tanks and during fish transport. Medical facilities use higher-purity PSA (93%) oxygen for clinical applications. Glass and metal industries use PSA oxygen for combustion enhancement. Wastewater treatment plants use PSA-supplied oxygen to enrich activated sludge aeration and reduce footprint. We supply complete PSA systems for all these applications, often as standalone projects without an associated ozone generator.

Reliability, maintenance and energy

PSA systems are widely regarded as the most reliable industrial gas-generation technology available — there are no consumables other than the air dryer's refrigerant and the eventual molecular-sieve replacement (typically 7–15 years, depending on duty and inlet air quality). The control valves cycle millions of times in service and are designed for 5+ year intervals between rebuilds. Energy consumption is dominated by the air compressor — modern variable-speed compressors paired with right-sized PSA modules deliver power figures around 0.4–0.6 kWh per Nm³ of 93% O₂. We service the complete PSA package including compressor, dryer, filters, PSA valves and molecular sieve as part of our standard maintenance contracts. With proper service a PSA system will outlast the ozone generator it feeds.

Key benefits

What you can expect from a PSA Oxygen Generators NZ project with Ozone Technologies.

Capacity range: 1 Nm³/h to 100+ Nm³/h
93–95% oxygen purity for ozone-generator feed
On-site generation — no cylinder or LOX deliveries
Continuous duty, fully automatic operation
5-year payback vs LOX, 10-year payback vs cylinder gas
Integrated control with ozone generator (purity interlock)
Designed for NZ climate — high-spec air dryer as standard
Molecular sieve life 7–15 years
Variable-speed compressor options for energy efficiency
Suitable for aquaculture, medical and wastewater O₂ as well

Quick answers

Common questions

What is a PSA oxygen generator?: PSA stands for Pressure Swing Adsorption. A PSA oxygen generator produces concentrated oxygen on-site from ambient air, using a pair of vessels filled with molecular-sieve material that selectively adsorbs nitrogen at higher pressure and releases it at lower pressure. The vessels cycle continuously, delivering a steady oxygen-rich stream — typically 93–95% O₂.
Why do ozone generators use oxygen feed gas?: Running an ozone generator on concentrated oxygen rather than ambient air dramatically increases efficiency: ozone output concentration rises from roughly 1–3 wt% (air-fed) to 8–14 wt% (oxygen-fed), and the energy cost per kilogram of ozone drops accordingly. Higher concentration also means a smaller contactor and less off-gas to manage.
What oxygen purity is needed for ozone generation?: Industrial ozone generators are designed to run on oxygen at about 90–95% purity, which is exactly what a well-sized PSA unit delivers. Gas dryness matters more than the last few percent of purity — incoming gas must be very dry (typically dewpoint below −60 °C) to protect the generator dielectrics.
Is on-site oxygen cheaper than bottled oxygen?: For continuous industrial use the answer is normally yes. On-site PSA removes the cost of trucked liquid oxygen or bottle hire / changeover, and removes the supply-risk that comes with depending on a delivery schedule. Payback depends on the size of the system and how much oxygen it uses — we can model it as part of the design phase.
What maintenance does a PSA oxygen generator need?: PSA is a proven low-maintenance technology. Typical service items are periodic inspection or top-up of the molecular-sieve material, routine valve servicing, replacement of inlet air filters, and checks on the compressor and dryer feeding the unit. Service is normally scheduled annually for continuous-duty systems.
Can PSA oxygen generators support aquaculture or industrial processes?: Yes. The same PSA technology that feeds an ozone generator can supply oxygen for direct oxygenation of recirculating aquaculture (RAS) and hatchery water, or for industrial processes that need a steady oxygen supply. See our aquaculture page for ozone + oxygen integration in fish systems.

More background: case studies · about Ozone Technologies · contact an engineer.

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+64 6 8432881 info@ozonenz.comNapier, New Zealand