2 replies to this topic

[Waheed 123]

Hello Forum Members,

 

I am working on Acid GAS dehydration project. Please guide me for design of distillation column or membrane separation unit for dehydration of hydrogen fluoride gas.

Raw gas composition 7% moisture in HF 

Desired product moisture level less than 500ppm.

 

[Art Montemayor]

Waheed 123:

 

You are posting your query in the Industrial Professionals Forum, where practicing, degreed engineers are expected to post.  I normally would presume you are a degreed chemical engineer, but I have serious doubts over your capabilities as a process design chemical engineer when I see that you fail to identify the specific, correct manner of specifying water moisture in a gas or liquid.  You fail to state what the 7% value represents: weight %, volume %, mole %, etc.  You also fail to identify the ppm value as parts per million weight or volume.  The information, as given, is essentially worthless.

 

Hydrogen fluoride is a highly toxic, corrosive, and dangerous chemical and as such is a compound held in a special category when it comes to selecting engineers capable of designing a unit operation handling this compound.  Not just anyone can be seriously trusted to design a unit operation dealing with this compound.  And no serious, practicing engineer can believe that an internet website is going to help generate a safe, correct design for drying hydrogen fluoride.  Certainly our Forums cannot take the responsibility - whether direct or inferred - for such a design.  Such is the gravity of any design involving this chemical that it is incredulous that someone with no experience or in depth engineering design experience would be employed to work on such a design.

 

Please explain in detail what the total scope of work of this "project" entails.  My 55 years of engineering tell me that this query has more dangerous potential than what we can read into your 3 sentences of insufficient basic data and any advice or suggestions offered by our members might lead to severe results.  This is the best guidance I can give based on your input.

[Waheed 123]

Hello Art Montemayor

 

First of all thank you so much for your reply and information about hazards associated with this chemical. In raw gas moisture composition is 7 weight % and desired is less than 200ppm by weight. Hydrogen Fluoride HF in gaseous form serves as a catalyst in alkylation process for combining C₃ and C₄ olefins and iso-butane to produce gasoline. In present practice moisture in HF gas causes severe corrosion in pipes, tubes and causes choking in Needle valves. In Stainless steel fittings at STP and Monel at elevated temperature more than 150C. It form  salt scales that block tubes ( OD.12.7mm). I have no experience dealing with this gas.