Air Separation and Nitrogen Liquefaction
We support air separation and nitrogen liquefaction teams investigating unstable operation, energy use, and product recovery. Reviews connect compression, purification, refrigeration, and distillation performance to the plant's configuration, product requirements, and operating conditions. Nitrogen liquefaction is in this scope and is assessed on its own operating basis — rate, product, and energy boundary — rather than as a side stream of an Air separation unit (ASU).
inquiries@cryobrothers.com. Thirty minutes, no charge. You leave knowing whether we can help and what a scoped engagement would look like.
What is the facility doing?
Choose the symptom closest to your operating problem.
Common operating problems
- Argon recovery below design, or lost entirely after every upset
- Specific power creeping up between turnarounds with no single cause
- Mol-sieve (front-end) cycles set at commissioning and never revisited
- Columns that will not settle after a rate change or on turndown
- A purity bump on every adsorber switch that the shift has learned to ride out
- Liquid and gas production split by habit rather than by economics
- A suspected cold box leak: frost or cold spots on the casing, perlite settling, or casing pressure creeping up
What we look at first
- Specific power, in the kWh per unit your plant already reports, at a given rate against your own best sustained window
- Argon recovery against the argon in the feed air, and the argon-to-oxygen production ratio against the plant's own best run
- CO2 breakthrough margin on the adsorber (molecular sieve) versus the cycle time actually being run
- Cold box pressure drop trended between derimes
- Compressor and expander efficiency drift, plus MAC and BAC discharge conditions
- Main condenser approach — the high-pressure to low-pressure (HP-to-LP) column temperature difference that sets the air pressure you pay for — and the crude argon condenser, trended across the run
- Cold box casing pressure and purge-gas flow, trended back to when a suspected leak, perlite settling, or frost and cold spots on the casing first showed
We define the energy and production basis before comparing performance, including the metering boundary, product quantities, operating period, and relevant operating conditions. The review states whether the comparison uses matched operating periods or an adjustment model.
Optimization opportunities
Operating questions worth investigating.
Argon recovery from existing plant capacity
Argon recovery depends on the main columns, the argon section, the product requirements, and how stable the unit runs — and they all interact. On a given unit the oxygen purity target may be one of the constraints, or it may not; what is usually missing is an agreed recovery boundary — which streams count, measured where — and an established answer on which constraints are active and which are only suspected. Naming them is how recoverable argon gets identified and quantified.
Adsorber cycle time against regeneration energy
Front-end purification cycles are commonly set once and left. Cycle time is a lever with real switch losses behind it — the blowdown and repressurization air the MAC pays for every changeover — as well as regeneration heat. It is also the barrier between the air and the sump, so we review purification performance and energy use together against the site's design and operating basis: feed variability, regeneration evidence, contaminant monitoring, and the downstream safeguards, with the LOX hydrocarbon analysis and the reboiler purge in the same window, never on the energy number alone. A breakthrough margin that is not stable is the more urgent finding, and worth knowing either way.
Turndown that does not cost you a restart
Units that follow demand often lose more in awkward turndown and recovery than in steady operation. We assess how turndown interacts with the operating envelope — the control setpoints and the alarm limits, not the protective trips — and distinguish control limitations from process or equipment constraints, rather than assuming the limits are conservative or assuming they are right. What moves goes through your management of change.
Liquid and gas production balance
The useful liquid-to-gas production split depends on demand, power cost, and plant constraints. We review those conditions together so your team can evaluate the operating choices.
Rare-gas recovery from the existing feed
Where a unit is equipped to recover krypton, xenon, or neon, the review can examine its recovery record and operating constraints. Scope and commercial relevance depend on the actual configuration and market requirements.
Electronics gasesThese are areas for review, not promises about your facility. The introductory call establishes fit and scope. Findings depend on the operating data reviewed during an agreed engagement.
How we help this process
Services for this process.
We review the main air compressor (MAC), booster air compressor (BAC), front-end purification, columns, and argon section. The work uses your historian and suitable comparison periods to identify the operating questions and evidence gaps. Nitrogen liquefaction, when present, is reviewed on its own operating basis.
Cold box that will not settle
Rate change, turndown, or a restart that will not hold: we start with the shift and the window in the historian. The working theory is tested against your own good runs before anyone opens a valve.
Operations TroubleshootingSpecific power off the plant's own best
We compare current specific power with suitable historical periods at similar rate, ambient conditions, and product mix. We document the comparison, its limitations, and the measures for evaluating a proposed change.
Performance OptimizationColumn pressure, level, reflux, and purity loops left in manual
Loops that live in manual because nobody trusts them are still deciding purity, rate, and recovery. We survey the bad actors, rank them, and leave the shift a documented Protuner tune.
Loop & Controls SupportOperating knowledge the next shift can use
Findings are written for the control room with owners and dates. Startup, turndown, and recovery sequences are taught using this plant's tags and procedures.
Training & Startup SupportMAC, BAC, and the machines the box depends on
The cold box is only as stable as the air it is fed. We group trips and near-misses by mechanism — compressor, turbine, adsorber, cooling water — and hand the shift a watch list aimed at those modes.
Reliability AdvisoryCrude argon you already paid to build
Argon recovery, oxygen specification, and crude-column stability interact. We review the loss points supported by your records and distinguish established constraints from those needing further investigation.
Argon & Specialty Product RecoveryWorking with your team
Higher specific power and lower argon recovery can persist without a plant trip.
Your team may already be investigating the columns and front end. We add dedicated review of the same records and document the checks that would distinguish the remaining explanations.
Both founders review the problem with your team. The agreed scope may cover specific power, argon losses, or column stability. You receive findings tied to the operating record, evidence limits, and a prioritized action list with owners and dates.
inquiries@cryobrothers.com. Thirty minutes, no charge. You leave knowing whether we can help and what a scoped engagement would look like.
Your operators take part in the review. The findings and their supporting trends stay with the plant so later shifts can recognize the same pattern and understand the reasoning.
A plant can meet its production target while using more power or recovering less argon than a suitable comparison period. The review checks whether the difference is an operating loss, changed conditions, or a measurement issue.
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