Absorption Process

Gas enters column bottom flowing upward. Lean solvent enters top flowing downward. Components dissolve from gas into liquid through mass transfer. Rich solvent exits bottom containing absorbed species. Treated gas leaves overhead. Driving force from concentration difference between phases.

Column Configuration

Vertical vessel with gas inlet at bottom, solvent distributor at top, trays or structured packing providing contact stages, rich solvent outlet at bottom, treated gas outlet overhead, temperature and pressure monitoring. Height provides contact time for target absorption efficiency.

Packing Selection

Structured packing offers high efficiency with low pressure drop suited for most applications. Random packing for smaller columns or economic designs. Trays handle high liquid rates or fouling services. Selection balances efficiency, capacity, pressure drop, and cost.

Operating Principle

Solvent flows across packing or trays contacting rising gas. Absorbed components transfer from gas to liquid phase. Solvent loading increases descending column. Gas purity improves ascending. Proper liquid-to-gas ratio achieves target removal efficiency.

Material Selection

Carbon steel for hydrocarbon absorption. Stainless steel for corrosive gases or solvents. Special alloys for severe chemical service. Packing materials resist process conditions. Design per ASME Section VIII with corrosion allowances.

Applications

Amine sweetening removing H2S and CO2 from gas, glycol dehydration absorbing water, sour water stripping, acid gas absorption, VOC recovery, ammonia scrubbing, and any process requiring selective gas component removal into liquid phase.

Solvent Systems

Amine solutions for acid gas removal. Glycol for water absorption. Caustic for sulfur compounds. Process-specific solvents matching target component chemistry. Solvent regeneration downstream restores absorption capacity enabling circulation.

Mass Transfer

Contact area from packing or trays. Residence time from column height. Temperature affects equilibrium and reaction rates. Pressure impacts solubility. Design optimizes these factors achieving specified removal at minimum capital and operating cost.

Pressure Drop

Lower pressure drop reduces compression costs. Structured packing typically 0.5-2 psi per foot of packing. Trays 2-6 inches water per tray. Design balances efficiency versus pressure drop for economic operation.

Control Systems

Solvent circulation rate controls absorption performance. Temperature monitoring tracks heat of absorption. Pressure control maintains operating conditions. Level instruments manage liquid inventory. Integration with regeneration coordinates overall treating system.

Construction Standards

Design per ASME Section VIII for operating pressure. Packing and internals per vendor specifications. Materials for process chemistry. Complete documentation with mass transfer calculations and performance guarantees.

ERGIL absorption columns provide efficient gas component removal through liquid absorption serving gas treating and chemical processing applications.