A request for help on data for Dimethyl Carbonate (DMC) 1

[Gerardd.]

Dear All,

I am looking for the specific heat capacity (Cp) in kJ/(kg.˚C) for Dimethyl Carbonate (DMC). I have found the molar heat capacity in a database, but this is expressed in Kelvin: 261 – 540 K.
For my calculation I need it expressed in kJ/(kg.˚C). Someone has told me I can also use the molar mass for DMC: 90.08 g/mol = 11,101 mol/kg. But from this point I don't know how to get to the specific heat capacity in kJ/(kg.˚C)
I am by no means a chemical engineer. My knowledge does not go far enough to figure this out. Is there someone who can help me with this issue?
Thanks

 

[pierreick]

Hi,
Based on data collected on the web, Cp liquid is within the range {153.2 -173.68} J/mol K; Teta (288.15-333.15) K
after calculation (Cp range)
Cp liquid 1.70071048 Kj/Kg C; Cp liquid 1.928063943 Kj/Kg C, between 15-60C

Pierre

 

[Gerardd.]

Thank you very much for the information and your quick reply Pierre !

 

[Gerardd.]

Dear Pierre,

Based on your answer for the Cp for DMC I have tried to determine the Cp for Ethylene Carbonate (EC).
I made the following calculation:
EC mol mass = 88,06 g/mol -> 1.000/88,06 = 11,356 mol/kg.

Cp = 158,51 J/mol K
Cp = 0,15851 kJ/mol x 1 kJ x 11,1356 mol/kg = 1,80 kJ/kg.

I would be most obliged if you could let me know if this is correct?

In addition, I have another question related to the Hvap for both compounds.
A google search for DMC says the Hvap = 369 kJ/kg. But I also find the following results: [37.70; 38.00] kJ/mol.
A google search for EC gives me only the answer in kJ/mol - I need this, again, in kJ/kg.

I don't know if the same calculation applies. When I, for example, try to calculate the Hvap for DMC I get a different result: 38 kJ x 1 kJ x 11,101 mol/kg = 421,838 kJ/kg. That's a difference of 52,838 degrees Celsius than the given answer online.
Am I using the correct formula, or should I use a other formula?

Thanking you in advance.

Gerard.

 

[pierreick]

Hi,
Your calculation is correct.
Pierre

 

[Gerardd.]

Thank you !

 

[Gerardd.]

Dear Pierre,

I am already very grateful for your help.
Now that I have been able to convert some data and know what my energy input should be for the different fluids. I now have to go to the next step: sizing the heated surface.

I have read the following: By equating the 2 equations for Q you can calculate the required heat transfer area on the heated surface for 1 second of contact time.
The equations are as follows:
1: Q = m x Cp x ΔT + m x ΔH[sub]vap[/sub]
2: Q = U x A x ΔT[sub]LM[/sub]

But I have really no clue how to equate these 2 equations..

Could you help me out with this?

Kind regards, Gerard

 

[pierreick]

Hi,
Let you study the material attached and get support from colleagues within your organization and/or third party.
This is an iterative calculation on U.
Attached calculator to help you out.

https://checalc.com/heat.html

https://www.freecalc.com/hx.htm

Good luck
Pierre