Project 02 · Petrochemical

Ammonia refrigeration & boil-off gas system for petrochemical plant.

LocationUnited States
ApplicationNH₃ plant + BOG handling
Capacity40 t/h
Cooling−37 / −5 / +5 °C
Project overview

Turnkey delivery for a major North American ammonia producer.

Technofrigo by Clauger delivered a complete process refrigeration system for a major North American petrochemical client producing ammonia. This turnkey installation provides multi-level cooling for process applications while safely handling boil-off gas from ammonia storage tanks — a critical requirement for continuous plant operations in high-ambient-temperature conditions.

The client

We worked directly with a major engineering and petrochemical group delivering technology, engineering, procurement and construction for synthesis gas, air separation, petrochemical plants, and fluid processing for refineries.

Why BOG management matters

Industrial ammonia storage requires large, low-pressure tanks maintained at low temperatures. In high-temperature seasons, heat transfer to storage tanks creates vapour or boil-off gas. Without proper management, this results in product loss, safety concerns and operational inefficiencies. Active refrigeration — not tank insulation alone — is essential for reliable operations.

The challenge

Three precise cooling levels plus BOG handling.

The client required a full-scale refrigeration system supplying cooling at three precise temperature levels to support ammonia production and storage operations, plus safe handling of vapour from storage tanks.

Process refrigeration requirements

  • Three-level cooling: −37 °C, −5 °C and +5 °C
  • Processing capacity of 40 t/h for the ammonia plant
  • Integration with existing ammonia production operations
  • Turnkey delivery with complete engineering and execution

Boil-off gas management

  • Safe handling of vapour formation (BOG) from ammonia storage tanks during high-ambient periods
  • Condensing boil-off flow during plant shut-down
  • Managing flash gases generated when re-liquefied ammonia returns to storage
  • Maintaining storage integrity while minimising ammonia losses
Our solution

Integrated refrigeration & BOG architecture.

We engineered a complete ammonia-based refrigeration system integrating process cooling with boil-off-gas handling — delivering reliable performance across all operating conditions including extreme temperatures.

Multi-level refrigeration system

The process refrigeration system features three oil-flooded screw compressors operating at three different pressure levels.

  • Processing of various process vapour streams at different temperatures
  • Heat exchangers and drum separators completing the refrigeration cycle
  • Efficient heat transfer across the required temperature range (−37 °C to +5 °C)
  • Reliable operation for continuous ammonia production

Boil-off gas (BOG) package

The dedicated BOG system safely handles vapour streams from ammonia storage.

  • Ammonia screw compressor — compresses ammonia gas from storage-tank boil-off
  • Condensation system — returns compressed gas to liquid state for tank return
  • Flash-gas handling — manages vapour generated during re-liquefaction and tank return
  • Shut-down cooling — condenses boil-off flow during plant shut-down periods
  • Heat-load management — transfers heat from low to high temperatures as required
Technical specifications

The numbers at a glance.

Performance and architecture in summary — full design dossiers available on request under NDA.
Refrigeration capacity 40 t/h processing capacity
Cooling levels Three: −37 °C, −5 °C, +5 °C
Process compressors Three oil-flooded screw compressors (multi-pressure)
BOG compressor One ammonia screw compressor
Refrigerant Ammonia (NH₃) — natural, efficient refrigerant
Application NH₃ production plant + storage-tank BOG management
Delivery scope Complete turnkey system — design, engineering, supply, installation
Site condition High-ambient temperature operating envelope
Project impact

What this installation actually delivers.

Impact 01 Process reliability

Three-level cooling ensures continuous ammonia production operations through the year.

Impact 02 Product conservation

BOG condensation eliminates ammonia losses from storage tanks during high-ambient periods.

Impact 03 Safe storage

Proper vapour management reduces pressure risks in ammonia storage operations.

Impact 04 Operational flexibility

System handles normal operations and plant shut-down scenarios reliably.

Impact 05 Extreme-temp performance

Proven effective in demanding ambient conditions where other systems struggle.

Impact 06 Natural refrigerant

Ammonia-based system provides efficient, cost-effective cooling — ideal for plants already handling NH₃.

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