7 replies to this topic

[sateeshkumar830]

Dear Sir,

 

My name is Satish Kumar from india.  i'm a post graduated in chemical engineering, working for the pharma industry the last 2 years.

 

My query is how to remove moisture content from a Tetrahydofuran solvent.  The initial MC is 2%.  We need to get below 0.1%.  Presently, we are adding sodium metal to the solvent and doing distillation to reduce the MC content.  Is there any other process to reduce Moisture content from Tetrahydrofuran solvent?  Waiting for your replies.

 

Thanking you sir..

[PingPong]

Why not try molecular sieves, or silica gel, or alumina?

[sateeshkumar830]

How to decompose Sodium Metal ???

[Art Montemayor]

Satish:

 

Please identify your acronyms before using them.  It’s common courtesy.  What is “MC”?  Do you mean moisture content?

 

Is your process continuous or batch-wise?  If you are in the Pharma(ceutical) industry, then I suspect it is batch.  What is the quantity of Tetrahydrofuran (THF) that you are proposing to dehydrate?  Why are you adding metallic sodium?  Is this to dry the THF or do you require it in your processing?  Please explain clearly what you have and what you are doing or proposing to do.  If you are batch distilling the wet THF, then explain how you do this in what kind of tower and under what conditions (a sketch would be the proper manner to describe this) and at what conditions of temperature and pressure.  Explain if you have an azeotrope or not – especially if you have other components in the THF+water mixture.

 

What PingPong is suggesting (adsorption) is probably one of the more obvious methods – especially if you have a batch process.  But you have to explain clearly what you have and what you propose – in more than 4 sentences.

 

Await your reply.  Please refer to the attached downloaded documents.

 Solvent_Drying.pdf   1.8MB   37 downloads

 THF Drying by the Still Process.docx   237.41KB   32 downloads

 

[PingPong]

How to decompose Sodium Metal ???

What do you mean?

Sodium is an element, so it can not be decomposed.

[sateeshkumar830]

thanks for your reply sir. present i'm working for research and development centre. generally we use 5 to 10 litre tetra hydro furan solvent. initial moisture content of the solvent is 1.5 to 2%. we need to get below 0.1%. we are taking 5liters solvent in round bottom flask , adding some sodium mental and doing distillation to reduce moistures content. after completion of distal at ion we are going to discard the residue matter remains in the flask. but sodium metal is not desalting in the residue matter. again we are taking out the sodium metal, dissolving in methanol solvent by giving 1 hour stirring, to discard it. is there any other way to reduce the moisture content and to discard the sodium metal?

[sateeshkumar830]

sorry not desalting. sodium metal is not dissolving in reside matter. we are able to discard the remained residue with sodium metal, because sodium metal fires when it catches the moisture. so again we are dissolving in methanol solvent to discard it.
waiting for your replies.

[MrShorty]

I don't think we have ever used sodium metal as a drying agent in our lab. In our lab, we either use mole sieves to remove water or a suitable distillation procedure. VLE data indicate that THF/water forms an azeotrope (~80mol% THF). You should be able to run a distillation that will draw a water rich mixture off the top and leave the dry solution in the kettle.