How to size reflux condenser?

[orion1]

Hi ,I want to size vertical condenser for methanol vapours above the batch reactor of 2 m3 volume. Reaction time is 1 hour, temperature is 50 C, and the pressure is 1 bar. Problem for me is to determine the quantity of methanol that evaporates in 1 hour.
Thanks.

Orion1.

 

[25362]

From the insufficient description submitted one can not answer your question.

1. At atmospheric pressure methanol boils at 64.7 deg C.
2. The heat of vaporization at BP is ~35.2 kJ/mol.
3. At 50 deg C, methanol's VP is about 415 mm Hg.
4. How much methanol is being formed or anyway present all along ?
5. Is the reaction exothermic, how much enthalpy is released ?
6. Do you plan to keep it at 50 deg C by refluxing ?
7. Are there also water or any other (volatile) compounds ?
8. Azeotropes may form and change the BP of methanol. For example, if dichloroethane is present you may have an azeotrope boiling at 49 deg C. With pentane the azeotrope boils at 31 deg C. With water and methyl butadiene you may get a ternary azeotrope boiling at about 30 deg C, and with bromomethane the binary azeotrope boils at 3.6 deg C (!)

As you see, there are many unknowns in your query. Would you be willing to fill in the details ?

Besides, beware of methanol's toxicity and flammability. Is the reactor duely grounded ?

Good luck.

 

[orion1]

Hello, 25362.

4. The reaction is between potassium hydroxide( 85%)- 64 kg and methanol (99,5%)-1600 lit .
5.Reaction is exothermic ,don't know how much enthalpy is realised.
6. Yes I plan to keep reaction mixture at 50 deg C by refluxing and cooling reaction mixture.
7. Water is present in KOH.


Yes I'm aware of methanol toxicity, flammability and of course reactor and pipeline are grounded.

Thanks .

 

[25362]

What are the expected products of the reaction?

 

[orion1]

Hi
The only product is pottasium methoxide.

 

[25362]

As far as I know the addition of KOH to methanol should be made slowly because of the large heat release.

Besides the presence of water may not be desirable because the methanolate tends to decompose back into KOH and methanol.

It seems that if the temperature is kept all along by jacket, or coil, cooling, at 50 deg C practically no methanol should vaporize: you'd need about 70 deg C to vaporize methanol at atmospheric pressure. And the question again is what would the speed of the reaction be at 50 deg C.

To get information on the heat released by the reaction, and the reaction speed, it would be logical to try asking Degussa AG, who, with their two plants in Germany, is considered one of the biggest continuous producer of methoxylates (for bio-diesel production).

Good luck.

 

[foxcreekfarm]

This process looks like the first part of a transesterification process to make biodiesel...