Heat Stable salts- HSS

Heat Stable Salts management

Introduction


Amine based gas treating systems can have problems with Heat Stable Amine Salts
(HSAS). HSAS cause corrosion, reduced amine capacity poor unit operations, reduced
solvent life and solvent disposal problems. The Dow Chemical Company has developed a
program that minimizes the problems associated with HSAS, maximizes solvent life, and
restores operational reliability. Dow’s Heat Stable Salt Management Program is based on
a low total cost approach to treat HSAS, reduce HSAS contamination, and minimize the
corrosion from HSAS. 

 Benefits of   Heat Stable Salts management

The problems associated with unmanaged HSAS can substantially increase costs and
reduce amine system equipment performance and reliability. The Heat Stable Salt
Management Program allows
the operator to effectively control HSAS and:
• Reduce corrosion and equipment replacement costs
• Reduce or eliminate solvent disposal and associated environmental costs
• Optimize amine system capacity for acid gases and avoid unit shutdowns
• Minimize maintenance costs due to system cleanings and frequent filter changeouts
• Avoid high energy and solvent usage.




  Heat Stable Salts management Program Elements 
Monitoring and Prediction
Solvent analyses determine the HSAS profile and predict when remedial action is
necessary.
Control Strategies
System configuration is studied to determine if operations can be adjusted to reduce the
formation of contaminants or to achieve more effective removal of contaminants upstream
of the amine system.
Neutralization Technology
Dow has developed and tested in both the field and laboratory a cost-effective means of
controlling HSAS via neutralization. The resulting neutralized salt is substantially less
corrosive than the amine salt. Therefore, the solvent can tolerate a higher level of HSASforming anions, and amine solution life is extended significantly, if not indefinitely.
UCARSOL™ DHM™ Neutralizer has been developed to easily and effectively neutralize
HSAS. Dow’s technical representatives will assist in organizing a neutralization and
monitoring program specific to your HSAS problem.
Removal
The system might eventually require some type of solvent purification, especially if
solvent losses are low. Purging the solvent to remove HSAS loses valuable amine and is
no longer economically or environmentally justifiable. Dow has developed a more costeffective and cleaner method of solvent purification: the patented UCARSEP™ Amine
Reclamation System for on-site and on-line salt removal. This process has been used to

clean up UCARSOL, MDEA, and DEA solvents without interruption of amine system
operations. For more information, call Dow at the numbers on the back cover of this
brochure.


Corrosion Effects
Figure 1†
 shows how corrosion rate increases with increasing formate ion concentration in
two MDEA solutions. Some other common anions have similar effects.


Effect of Neutrolization


Heat stable amine salt management/neutralization reduces the operating and corrosion
problems associated with HSAS. This control increases the capacity of the solvent for the
allowable HSAS anions and greatly reduces the frequency of solvent purification,
reclamation, or disposal. Figure 2 provides a dramatic illustration of the effectiveness of
Dow’s Heat Stable Salt Management Program, with a reduction in solvent purification and
cost while maintaining low corrosion and smooth operations.

http://www.dow.com/PublishedLiterature/dh_0039/0901b803800391dc.pdf