Function in Dehydration Systems

Rich glycol saturated with water from the contactor vessel flows to the still column where heat applied in the reboiler section vaporizes water at temperatures typically 190-205°C. The rising vapor passes through bubble cap trays or structured packing, contacting descending liquid glycol. This countercurrent flow strips remaining water from the glycol while heavier glycol molecules remain in liquid phase. Lean glycol exits the bottom at concentrations of 98.5-99.0%, ready to return to the contactor. Water vapor exits overhead to the condenser or atmosphere.

Column Design

ERGIL engineers still columns based on glycol circulation rate, water loading, and target lean glycol concentration. Typical designs include 4-8 theoretical stages achieved through bubble cap trays or structured packing. Carbon steel or stainless steel construction withstands high temperatures and glycol service. Internal distributors ensure uniform liquid flow across packing surfaces. Vapor disengagement sections prevent glycol entrainment in overhead vapors.

Reboiler Integration

The column base integrates with fire tube reboilers, electric immersion heaters, or thermal fluid heating systems. Heat input drives water vaporization while maintaining glycol below degradation temperatures around 210°C. Temperature control prevents glycol thermal breakdown that forms acidic compounds and reduces system efficiency. ERGIL sizes reboilers for required heat duty with adequate turndown for varying loads.

Performance Optimization

Column height and diameter optimized for vapor velocity and liquid loading. Proper sizing prevents flooding or excessive pressure drop. Tray or packing selection balances efficiency, pressure drop, and fouling resistance. Temperature profiles monitored to ensure complete water removal without glycol degradation. Insulation minimizes heat losses and improves thermal efficiency.

Applications

Natural gas dehydration units from 1-100 MMSCFD capacity, gas processing plants, wellhead compression facilities, and pipeline conditioning stations. Handles sweet or sour gas service with appropriate materials. Suitable for TEG, DEG, or mixed glycol systems across varying operating pressures and gas compositions.

Operational Features

Atmospheric or slight vacuum operation depending on system design. Continuous operation with minimal attention required. Temperature and pressure monitoring throughout column height. Level control maintains proper liquid inventory. Optional analyzers verify lean glycol concentration. Designed for 20+ year service life with proper maintenance.

Standards and Testing

Designed per ASME Section VIII pressure vessel code. Fabrication with certified welding procedures and NDT inspection. Hydrostatic testing validates integrity. Insulation and weather protection for outdoor installations. Platforms and ladders provide maintenance access per OSHA requirements.

ERGIL still columns deliver reliable glycol regeneration with proven distillation technology, ensuring consistent dehydration performance and long-term system reliability.