[Kwiatostan]

Hi,

I'm designing an industrial process of recycling waste polyurethane foam via aminolysis/glycolysis (solvolysis) reactions in a batch reactor.
Now I stucked calculating thermodynamics of this process. Could you please advise how to corectly, step by step make the calculation?

Just for information, depending on the material formulation I'm going to use (Slabstock foam flakes, Integral foam flakes, etc.) as for amination di-n-butylamine will be used whereas for glycolysis a mixture of diethylene glycol and dipropylene glycol will be used.
Homogenous product is expected which can be applied as addition to new PUR formulation.

Many thanks for your help.

[Arkcon]

Welcome, Kwiatostan:, to the Chemical Forums, I hope you get the help you need.  I'm not one of our local experts on the topic, but I'll try to help you get closer to an answer.

Hi,

I'm designing an industrial process of recycling waste polyurethane foam via aminolysis/glycolysis (solvolysis) reactions in a batch reactor.

OK, since you're designing an industrial process, I've gone and moved this thread to Chemical Engineering, and I hope you get the help you need from experts.

Now I stucked calculating thermodynamics of this process. Could you please advise how to corectly, step by step make the calculation?

This is difficult for two reasons.  First of all I suck at thermodynamics.  That's OK, we have some experts here.  But your question is too broad, it almost doesn't make sense.  Thermodynamics will teach you the order of reaction, the rate of reactions, the spontaneity of a reaction.  And you can investigate those under a variety of conditions.  And you should ask about those, asking for the Thermodynamics is asking, for the step by step everything.  Which isn't really a question a person can answer.

[Kwiatostan]

Hi Arkcon,

sorry for being too general. I was wondering whether someone will be willing to support. I'm positive surprised.

As for the process I plan to use a reactor according to patent DE10313150A1, an overview picture below:



It is a simple reactor with oil heating jacket with 3 reaction/heating zones, special designed auger shaft (kneading and stirring shaft) (also with heating jacket) and a filtration unit, etc.)

Depending on foam used process will be coducted in temperature 210°C for integral flexible foam, 220°C for slabstock flexible foam and 200°C for rigid foams. Under atmospheric pressure in presence of nitrogen. Water vapour from moisture closed within foam flakes (2-5cm) will be removed via entgassing unit.

Process consists of 3 reactions:

Aminolysis



Glycolysis (urethane bond)



Glycolysis (urea bond)



For aminolysis di-n-butylamine (DNBA) will be used, for glycolysis a mixture of diethylene glycol (DEG) and dipropylene grlycol (DPG). Obviously the ratio thereof will vary considering the PUR foam used.

As mentioned earlier, homogenous product is expected as a mixture of polyol, dispersed nanoscale oligourea particles (12-20nm), primary amines and carbamate.

I want to calculate energy which has to be delivered to break the urethane and urea bonds to regain the polyol used.
I wish also to confirm that temperatures I assumed are suitable to conduct the reactions.

The problem I faced is that I can't find thermodynamics data in T=298K for PUR foam, DNBA, DPG and DEG  as Cp, enthalpy etc. to calculate specific heat and the change of standard enthaply taking the reactions in aforementioned temperatures.

If additional information are needed, please let me know.

Many thanks