Equipment
Amine sweetening systems remove H₂S and CO₂ from sour gas to meet required downstream or sales-gas specifications. SPEC configures the system around feed-gas composition, operating conditions and required outlet specification.
Application
Natural gas may contain hydrogen sulphide (H₂S) and carbon dioxide (CO₂). These acid gases can cause corrosion in the presence of water. Amine sweetening reduces H₂S and CO₂ to the concentrations required by the downstream process or sales-gas specification.
The solvent and process configuration are selected from the feed composition, operating conditions and the required outlet H₂S and CO₂ concentrations. Amine sweetening is typically selected where the duty calls for:
Removal of high concentrations of acid gas from the inlet stream
Reducing CO₂ and H₂S to sales-gas specification
Meeting sulphur content regulations
Preventing corrosion in downstream equipment and pipelines
Increasing the heating value of the natural gas
Continuous operation, with the amine regenerated in the loop
Removal of organic sulphur compounds with the addition of physical solvents
Process
Sour gas passes through an inlet scrubber to remove contaminants before contacting the amine. The scrubbed gas enters the absorber, where trays or structured packing provide the contact area for the down-flowing amine to absorb the acid gases. Sweet gas leaves the top of the absorber; rich amine leaves the bottom.
Rich amine passes through a flash tank and the rich/lean heat exchanger before entering the regenerator. Reboiler heat releases the absorbed acid gases. The overhead condenser cools the acid-gas and water-vapour stream, condensing water that is separated in the reflux accumulator and returned to the column. The remaining acid gas is routed to the specified downstream handling system. Regenerated lean amine is heat-exchanged, cooled and pumped back to the absorber.
System configuration
System configuration varies with process duty, operating conditions and project requirements.
Removes contaminants from the sour gas before it meets the amine; typically integrated with the absorber.
Brings the sour gas into contact with down-flowing amine over trays or structured packing, where the acid gases are absorbed.
Releases hydrocarbons and hydrocarbon condensate carried by the rich amine.
Preheats the rich amine before the still column and cools the lean amine on its way back.
Regenerates the amine: acid gases leave at the top and lean amine leaves at the bottom.
Supplies the heat that releases the absorbed acid gases from the amine.
Cool the overhead stream and separate the condensed water, which returns to the still column.
Also in the scope of supply
Options
The equipment can be supplied skid-mounted. Final equipment arrangement and delivery format depend on process duty, transport constraints and site requirements. Design pressure, temperature and capacity envelope to be confirmed by SPEC engineering.
Advantages
Removes high concentrations of CO2 and H2S in a single treatment step.
The solvent is stripped and returned in the loop rather than replaced in batches.
Organic sulphur compounds can also be removed with the addition of physical solvents.
Engineering
Amine units are designed with process simulation software built for amine systems, together with in-house design tools. This accounts for the variables that govern amine performance and confirms the design against its specification before fabrication.
Enquiries
Send us your process data and operating conditions, and we will review the duty with you.
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