Reflux System Function

CO2 purification columns remove impurities through distillation. Overhead vapor condenses in exchangers then flows to reflux separator. Vessel separates liquid CO2 from non-condensable gases. Liquid returns to column as reflux. Gas vents containing impurities. Level control manages reflux ratio.

Separator Design

Horizontal or vertical drum with condensed CO2 inlet, vapor space for non-condensable disengagement, liquid collection zone, vapor outlet to vent or recovery, liquid outlet to reflux pump, and level instrumentation. Design provides surge capacity buffering condenser variations.

Operating Conditions

Pressure 15-25 bar typical for CO2 condensation. Temperature -20C to +10C depending on pressure and purity requirements. Low-temperature operation requires proper material selection. Insulation maintains conditions reducing refrigeration load.

Phase Separation

Inlet allows flash gas separation. Non-condensables like nitrogen, oxygen, argon accumulate in vapor space. Periodic or continuous venting removes impurities. Liquid CO2 settles maintaining inventory for reflux. Clean separation essential for purification efficiency.

Material Selection

Stainless steel construction handles low-temperature CO2 liquid and vapor. Design prevents brittle fracture at operating temperature. Materials resist corrosion from trace contaminants. Thermal insulation reduces external heat gain.

Level Control

Maintains liquid inventory for stable reflux flow. High level prevents gas carryover to pump. Low level protects pump from cavitation. Controllers coordinate with column operation and condenser duty.

Non-Condensable Removal

Gases like nitrogen and oxygen don't condense at CO2 conditions. Accumulate in separator requiring venting. Vent system removes impurities while minimizing CO2 losses. Critical for maintaining product purity specifications.

Applications

CO2 purification in carbon capture systems, natural CO2 well processing, beverage grade CO2 production, food industry CO2 purification, and any fractionation process separating high-purity carbon dioxide from contaminants.

Reflux Control

Level control adjusts reflux flow to column. Proper ratio maintains separation efficiency. Integration with column controls optimizes purification. Surge capacity accommodates process variations without upset.

Performance Benefits

Enables efficient CO2 fractionation through proper reflux management. Removes non-condensables maintaining product purity. Provides surge capacity for stable operation. Simple proven technology for CO2 purification systems.

Construction Standards

Design per ASME Section VIII for low-temperature pressure service. Materials with impact testing for cold conditions. Insulation per cryogenic standards. Complete documentation with thermal design calculations.

ERGIL CO2 reflux separators provide reliable liquid-vapor separation enabling efficient carbon dioxide purification in industrial gas processing systems.