Amine desulfurization and filtration methods are widely used in refineries, dry gas and LPG processing. H₂S and CO₂ from the gas stream are absorbed by the amine solution, forming an alcoholic amine salt solution. H₂S & CO₂ can then be stripped from the gas through a heating process, allowing the amine to be regenerated for reuse.

During the process of amine desulfurization, besides absorbing H₂S and CO₂, the amine solution may also react with other materials or carry solid particles from the pipe, such as heat-stable salts, sulfide, iron dust, causing foaming & fouling, lower absorption efficiency, or even damage downstream equipment.

Due to the possible problems in the process, amine filtration becomes an important process  with gas filtration. Feature-Tec has provided optimized solutions for Amine Desulfurization for years.

Problems in the Process :

• Amine foaming in contactor tower and stripper column, due to reaction between high concentration of hydrocarbons and organic acids, cause loss of amine solvent, poisoning of catalyst and lowering contact efficiency.
• Liquid hydrocarbons from the natural gas, FeS/SS , chemical treatment agents cause fouling in the cooling tower and heat exchangers, thus lowering the efficiency, corroding the heat exchange meter and damaging the heat equipment.
• Frequent amine top up results in increased maintenance costs. The formation of heat stable salts and cyanide cause fouling of the carbon bed, which in turn causes an increase in the consumption of energy. This also causes an increase in the use of anti-foaming agents which increases the amount of waste produced.

Causes for Foaming

• Foaming of the amine is caused by hydrocarbons and organic acids.
• Treated fluid and anti corrosion agents.
• Oil, inhibitor and welding fluid.
• Water contaminants.
• Suspended solids (indirectly causes amine foaming)
• FeS
• Carbon powder
• Iron oxides
• Inefficient filtration and separation of inlet flue gas
• Cotton string-wound filter
• Unsatisfactory filter material

Possible Suspended Solid Content Causes

• Rust, iron sulfide from sour gas pipeline due to corrosion
• Mineral deposits, Rust and pipe scale from water
• Iron sulfide, rust, pipe scale and activated carbon  from activated carbon bed filter

Keys to Maintaining Clean Systems

• Limit flow rate of lean amine and natural gas to reduce the carbohydrate concentration.
• Fully filtrate the incoming sour gas to remove contaminants such as liquid hydrocarbons, FeS/SS solid particles and water.
• Ensure sufficient pre-filter and after-filter for activated carbon bed.
• Select an appropriate mechanical filter material.
• Use anti-foaming agent temporarily.

Amine Desulfurization and Filtration Solutions

 

1.  Sour Gas Filtration: Prior to processing with amine cleaning , solid and liquid impurities present in the sour gas should be removed. Feature-Tec’s coalescer filter will be able to filter off and intercept the solid and liquid impurities such as iron sulfide and rust efficiently.

2.  Amine Recovery:  Filter coalescers can be installed to recover amine carried over by the gas, reducing loss of amine and cuts maintenance costs.

3.  Amine Foaming Prevention: Polypropylene FSH filter cartridge provides high dirt holding capacity applicable to rich amine and lean amine solution filtration, removing solid particles. Activated carbon filter can be used to remove gases in the amine solution, preventing amine foaming, protecting downstream equipment.

4.  Feature-Tec’s SelfClear® Automatic Filter System is the best self cleaning solution to deal with rich amine filtration, removing small and deformed particles.

 

Feature-Tec Amine Filtration & Desulfurization Applications

 

 

Advantages and Special Features of Feature-Tec’s SelfClear® Automatic Filter System

Advantages	Special Features
Consistent Filtration Efficiency	Patented cartridge structure distributes pressure around the cartridge, forming even filter cake. Self-locking filter mechanism ensures filter stability. Filtration precision of 0.5 – 400 microns. SelfClear® filters assures stable performance with self cleaning, long service life.
Efficient Backwash & Water Conservation	Patented back flush system requires only 0.2-20 mins to complete normally. Less than 0.5% of filtrate fluid used for removing even sticky solid particles. Air (N₂ gas) or instrument assisted backflushing are also available.
Fully Automated Control Allowing Continuous Filtration	Automatic PLC control, touch screen operation. Fully automatic, semi-automatic and manual operating modes available. Automatic switching between work and backwash modes ensures a continuous fluid system with minimal pressure loss. Optional explosion-proof devices are available.
High Corrosion Resistance	Various choices of materials for the system providing resistance to chemicals, acids, alkalis, salts, solvents and etc.
Long service life span with reliable operation at low operating costs	ISO 9001 quality system applied to all manufacture procedures including materials, accessories and suppliers. 100% overall operation tests are performed before delivery. Easy installation and operation, almost no routine maintenance required. Patented design of the filter unit assumes almost no damage due to wear and tear, resulting in spare parts being rarely required. After years of industrial practical services, verifications are made to prevent filtration and backwash efficiency deterioration through its service life time.
Small Space Requirement	Option for modular system can be installed in a configuration complying to space restraints.
Strong Technical Support	Feature-Tec‘s experienced engineers provide comprehensive pre and post sales technical support and services