RNG Cryogenic Processing and BioLNG
We support renewable natural gas facilities with cryogenic processing, including biomethane liquefaction to produce BioLNG, cryogenic nitrogen rejection, and associated CO2 recovery and liquefaction. The review covers the installed cryogenic process and its agreed interfaces with feed pretreatment, storage, and loading. We evaluate feed conditions against the actual process requirements and account for recovered, reused, and discharged methane streams separately. A membrane or PSA upgrading plant with no cryogenic stage is outside that scope.
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
- Liquefier trips or reduced availability during changes in digester or landfill gas feed
- CO2 freeze-out and cold-section plugging on a schedule everyone has learned to live with
- Nitrogen and oxygen holding landfill product just off pipeline or liquefaction spec
- Siloxane and sulfur carryover quietly fouling everything downstream of where the pretreatment stopped working
- Flash and vent losses at truck loading that nobody has weighed against what the molecules are worth
What we look at first
- Feed composition variability against the cold section's actual operating basis — not the basis from the proposal
- CO2 and moisture breakthrough ahead of the cold section, against the pretreatment cycle actually being run
- Liquefier specific energy and availability against its own best window, by feed rate
- Nitrogen rejection unit (NRU) performance where landfill gas is the feed
- Boil-off and flash handling at storage and loading, closed as a ledger
- Who operates and who owns — on these sites they are often different companies, and we establish it early so findings land with whoever can act on them
Optimization opportunities
Operating questions worth investigating.
Feed variability and cryogenic availability
Digesters and landfills produce what they produce, seasonally and daily, and cold sections rated for the proposal's flat line trip on the reality. We assess how that feed interacts with the operating envelope — setpoints and alarm limits, not the trips that protect the box — and distinguish control limitations from process or equipment constraints. Establishing where those limits genuinely sit is the difference between a plant that follows the feed and one that fights it.
Flash losses during storage and loading
Every liter that flashes at loading or leaves as boil-off was product the whole site existed to make. Closing the loss ledger from storage to truck names where it goes — and separates transfer practice from equipment and from measurement rather than assuming which it is.
CO2 recovery as a co-product
Sites already separating CO2 may have a co-product in that stream, and the equipment involved is the same industrial-gas family as the rest of the cold section. Composition, conditioning needs, the quality basis, and delivery constraints come before any investment decision — establishing that basis is the work.
CO2 liquefaction, purification & capture conditioningPretreatment and cold-section performance
Pretreatment records are relevant to freeze-out, fouling, and breakthrough investigations. We compare those records with cold-section events and distinguish supported causes from those still needing checks.
These 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 cryogenic liquefaction, polishing, rejection, and loading stages using feed history and plant records. Findings are written for the operating team and the owners responsible for acting on them.
A cold section that trips or plugs
Freeze-out, fouling, restarts that will not hold: the feed history and the shift's account come first.
Operations TroubleshootingLiquefier off its own best
Specific energy and availability, by feed rate, written down in plant data.
Performance OptimizationLoops the vendor tuned once
We review how the cold-section loops respond to feed variation and distinguish control questions from process and equipment constraints.
Loop & Controls SupportA first-time cryogenic crew
We work with the crew's existing experience to document cryogenic operating sequences, job aids, and training needs for the actual plant.
Training & Startup SupportThe machines between digester and offtake
A recurring watch list sized for a small site, aimed at what actually stops shipments.
Reliability AdvisoryLosses at the loading bay
Flash at loading, storage boil-off, and methane slip to the CO2 side, accounted point by point.
Argon & Specialty Product RecoveryWorking with your team
Feed variability and recurring freeze-out need to be assessed against the cold section's operating limits.
Your team and equipment suppliers retain the wider upgrading context. We focus on the cryogenic operating record and identify which questions need additional evidence or specialist follow-up.
Both founders review the agreed cryogenic operating question. Findings can cover feed-related constraints, availability, and loading losses, with evidence limits and actions assigned to the relevant operating or ownership team.
inquiries@cryobrothers.com. Thirty minutes, no charge. You leave knowing whether we can help and what a scoped engagement would look like.
The site keeps the findings, supporting records, and responsibility for follow-up, so the next feed change can be assessed against an established operating record.
Trips, plugging, and loading losses can have different causes. Reviewing feed, pretreatment, and cold-section records together helps establish which explanations are supported.
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