Synthesis Loop Operation

Ammonia synthesis operates at 150-300 bar converting nitrogen and hydrogen over catalyst. Product ammonia condenses upon cooling. HP separator removes liquid ammonia from unreacted gas at synthesis pressure. Purified gas recycles to reactor while liquid ammonia flows to storage.

Separator Design

Vertical pressure vessel with synthesis gas inlet after product cooler, ammonia condensate collection zone, gas outlet returning to synthesis loop, liquid outlet to pressure letdown and storage, and vapor-liquid separation internals. Heavy-wall construction handles extreme operating pressure.

Operating Pressure

Design pressure 200-350 bar matching synthesis loop conditions. High pressure keeps ammonia liquid at ambient temperature. Materials and construction per ASME Section VIII Division 2 for extreme pressure service.

Separation Process

Cooled synthesis gas contains liquid ammonia droplets. Separator provides residence time for gravity disengagement. Ammonia being heavier settles to bottom. Unreacted H2 and N2 return overhead to compressor and reactor. Clean separation maximizes ammonia recovery.

Material Selection

Carbon steel or chrome-moly alloy for high-pressure service. Proper steel grades prevent hydrogen embrittlement. Welding procedures qualified for ammonia and hydrogen service. Design accommodates thermal cycling during startup and shutdown.

Ammonia Recovery

Liquid ammonia flows through pressure letdown to intermediate and storage pressure. Multi-stage letdown recovers refrigeration from flashing. Final storage typically 18-20 bar at -33C or ambient temperature.

Applications

Ammonia synthesis plants using Haber-Bosch process, fertilizer production facilities, and industrial ammonia manufacturing. Critical equipment in plants producing 500-3000 tons per day ammonia.

Impurity Removal

Inert gases like argon accumulate in synthesis loop. Purge stream prevents buildup. HP separator ensures purge gas contains minimal ammonia reducing losses. Clean separation improves overall process efficiency.

Level Control

Level transmitter controls ammonia withdrawal maintaining inventory. Interface between liquid ammonia and gas phase managed carefully. Controllers coordinate with synthesis loop pressure and flow requirements.

Performance Benefits

Efficient ammonia recovery maximizes production. High-pressure separation eliminates need for additional compression. Clean gas recycle maintains synthesis loop efficiency. Proven separation in demanding high-pressure service.

Construction Standards

Design per ASME Section VIII Division 2 for pressure above 200 bar. Materials meet hydrogen service requirements per API 941. Relief systems sized for worst-case scenarios. Complete documentation with stress analysis and material certifications.

ERGIL HP ammonia separators provide reliable high-pressure separation in ammonia synthesis delivering efficient product recovery in fertilizer production.