3 replies to this topic

[Rahimzadeh]

Dear:

Please clear me ,what will happen when caustic leak into amine circulation in gas sweetening plant?

best

[Art Montemayor]

What is the origin of the caustic?

 

What allows it to leak into an amine circulation system?  Also, there are a variety of "amine" processes.  Which amine, specifically, are you referring to?  Please be specific when describing a process.  General descriptions will never generate a specific response.

[Rahimzadeh]

Dear Art:

 

IN OUR SRU PLANT, WE USE MDEA FOR SULPHUR RECOVERY.

YOU KNOW WELL THAT FOR ADJUSTING THE AMINe PH, WE NEED TO INJECT SOME CAUSTIC TO the CIRCULATINg AMINE.

IN OUR PROCESS, the CAUSTIC DRAIN TANK IS CONNECTED TO the AMINE CIRCULATING LINE.  ON UNINTENDED CASE, WILL CAUSTIC DRAINAGE TO the AMINE CAUSE a PROBLEM OR NOT?

REGARDS

[Art Montemayor]

m.r.rahimzadeh:

 

If you insist on having your caustic soda tank piped directly to your MDEA circulating line, you are taking a recognized risk that MDEA contamination might occur if:

• the block valve between the tank and the MDEA line leaks;
• An operator might mistakenly open the block valve and admit caustic to the MDEA without realizing it.

Yes, if you have positive communication between tank and MDEA circulating line you are running a risk that could easily run into some very serious problems.

 

I never recommend that operations maintain a permanent connection between the circulating MDEA solution and any additive.  This is certainly not a best practice.  If you must maintain such a connection because you want convenience - which I can readily understand from the point of view that you are dealing with a hazardous chemical in caustic soda - then I recommend that you install a double-block-and-bleed valve arrangement in the common line between both tank and circulating line.  Over-dosing your MDEA can virtually force you to dump the entire MDEA charge and that constitutes not only a lot of chemical expenditure, but also downtime and other major costs.