5 replies to this topic

[alirehman]

Huy there  I am a student of chemical engineering currently working on a project "Acetic Acid production by direct oxidation of ethylene". I am facing problem in designing vaporizer  as I highlighted my problem which is I only have ethylene out and water in flow rate. Also I am damn confused which sort of vaporizer should I design and how it should be...? or would there be any other equipment associated with this vaporizer ?

 

For Ethylene

melting point = -169.2 ^oC

boiling point = -103.7 ^oC

 

while water recycled is at 30 ^oC

 

My keen request to all of you is "Please help".

 

[fallah]

alirehman,

 

As far as I know in an ethylene vaporizer the methanol vapor is normally used as heating media while the spent methanol (in liquid) itself would be continuously vaporized in another exchanger by low pressure steam and methanol vapor returned to the vaporizer...

[alirehman]

+ Naseer Fallah there is no methanol in such a process only ethylene is out there as primary raw material which needs to be vaporized. As I already discussed that;

For Ethylene

melting point = -169.2 ^oC

boiling point = -103.7 ^oC

 

and furthermore reaction condiations in reactor are 160–210oC over a solid catalyst. That's why I am confused.

Also I am thinking about electric vaporizer if it is possible.

[senthil13]

Is the ethylene you are receiving a gas or liquid. Ethylene sometimes supplied as super critical fluid. We need to be really careful designing a heat exchanger or vaporizer for it.   Please follow the pressure-enthalphy diagram to understand the phase change of Ethylene.

 

Please specify pressure, temperature and phase of  C2 you are receiving? Are you taking a pressure drop across a control valve?

[Art Montemayor]

alirehman:

 

You are furnishing unrelated and confusing information meant to generate a recommendation.  That is why Fallah is responding in the way that he has.  He - like most of us - are confused by the explanation of producing Acetic Acid by oxidation of ethylene.  Apparently, all you want to do is design an adequate LIQUID ethylene (at what temperature & pressure?) vaporizer to feed the resultant vapor (presumably saturated?) to some process - and that is all.  So why even mention Acetic Acid?

 

Why don't you use common sense and give us the BASIC DATA:  conditions of the liquid fluid to be vaporized, the desired conditions of the vaporized fluid, the flow quantities involved, and the heat source(s) available to carry out the vaporization and their flow rates?

 

Why do you give the forum un-related and unnecessary information like the "melting point" of ethylene?  Are you vaporizing a SOLID?  I don't think so!  You state the "boiling point" is -103.7 ^oC - as an engineering student you should already know that this information is irrelevant if you don't also identify the PRESSURE corresponding to that boiling point!  Liquids boil at different temperatures under different pressures.  That is basic knowledge.

 

Our key and expert engineers - like Fallah - have all the knowledge and expertise to help you.  But you must help them to allow them to help you.  You help them by furnishing clear, concise, specific basic data and information related to your query.  Otherwise this thread will quickly convert itself into a guessing contest and you will gain or profit nothing from it - only a lot of lost time and effort.  Help our Forum members and you will be rewarded with their valuable advice and recommendations.  Let this be a Lesson Learned.

[fallah]

alirehman,

 

As the subject implies and based on the valuable advices of Art as always, please ignore submitting irrelevant info and focus providing the info specifically about the ethylene vaporizer you are trying to design...otherwise you will get nothing by giving various irrelevant info about the other parts of the system in which the ethylene vaporizer is only a part...

Edited by fallah, 07 March 2016 - 01:16 PM.