What is Amine Scrubbing (Acid Gas Removal)?


Amine scrubbing/acid gas removal processes utilize amines or specialty solvents to remove acid gases such as H2S and/or CO2 from Refinery Fuel Gas (RFG) to meet the gas quality specifications. The sour gas is contacted with lean amine in the contactor tower. An acid-base reaction occurs, binding the acid gases to the amine with a weak bond. The rich amine then flows to a regenerator, where heat breaks the weak bond between the amine and the acid gas, releasing the acid gas and regenerating the amine for re-use.


The acid gases exit the top of the regenerator for further treatment while the lean amine is recirculated back to the contactor in a recirculating loop. Liquid amine treating can also be used to remove H2S from Liquid Petroleum Gas (LPG). In this case a liquid-liquid contactor is used to contact the lean amine with the liquid LPG.


What are the benefits of acid gas removal?


  • Achieve oil production quotas via reliable treatment of acid gases that otherwise bottleneck unit operations
  • Provide consistent fuel gas quality to ensure reliability of all burner operations across the refinery
  • Minimize refinery off gas emissions through effective acid contaminant removal from the RFG


Production Challenge/Pall Solution for Amine Scrubbing


Challenge Solution
Reduced refinery shipments due to AGRU operational issues curtailing gasoline, jet fuel and diesel production. KO pots, mesh pads, cyclonic devices and conventional filter-separators may not effectively remove aerosol-sized liquid hydrocarbon droplets or fine solids. 

Improve productivity and reliability with consistent RFG quality by controlling AGRU foaming and fouling.


  • High efficiency coalescers can also be used downstream of the contactor on the sweet gas to recover amine mechanical losses and prevent carryover of amine into downstream RFG.


Environmental exceedances due to venting of off-spec RFG from poor AGRU operation. 

Environmental compliance in the AGRU by control of foaming and fouling issues.


Solid particle contaminants in amine systems are mostly very fine corrosion products that may not be adequately removed by filters that exhibit unloading, media migration, channeling or poor sealing.

range of absolute and nominal rated filter elements is available to reduce suspended solids to <5 ppmw, keep the amine clear, and reduce foaming and fouling issues.


For enhanced solids control, add filtration to the rich side. Total sour gas worker exposure will typically be lowered due to the reduced system maintenance on the rich side.


Caustic treater upsets from amine carryover in the sweetened LPG 

Freedom from caustic treater upsets due to amine carryover from liquid amine treaters.


Install a high efficiency liquid/liquid coalescer downstream of the liquid contactor to remove residual amine and ensure corrosion test quality is achieved.


Rapid cleanup needed Apply mobile filter or liquid/liquid coalescer skids.



Acid Gas Removal Process Flow Diagram




Key Application in Acid Gas Removal Process/ (other applications not shown)


Application Pall Product Customer Benefits
Contractor inlet coalescer

SepraSol Plus liquid/gas coalescer

Medallion HP liquid/gas coalescer

Refinery productivity, reliability and compliance via AGRU protection from slug upset
Contractor outlet coalescer

SepraSol Plus liquid/gas coalescer

Medallion HP liquid/gas coalescer

Improve burner reliability and reduce burner maintenance by removing amine carryover
Amine filter (add rich side for enhanced performance) 

Ultipleat® High Flow filtersCoreless filtersMarksman™ filtersProfile® II polypropylene filter cartridgesNexis® II melt blown filter cartridges


Refinery productivity, reliability and compliance via AGRU protection from foaming and fouling causing RFG issues
Liquid hydrocarbon removal from amine

PhaseSep EL Liquid/Liquid coalescers


Reduce upsets in downstream sulphur plant

Amine removal from LPG

PhaseSep EL Liquid/Liquid coalescer


Improve caustic treater reliability, meet LPG quality specs (corrosion test)


Depollution/cleanup filter

Mobile filter or liquid/liquid coalescer rental skid

Rapid recovery from upsets, return to refinery productivity, reliability, compliance

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