3 replies to this topic

[uiucche94]

I am working on an emissions estimate for a new batch process. One of the steps involves partially stripping solvent from a product solution by a single stage atmospheric distillation. I need to come up with an estimate of solvent loss from the condenser vent, and I'm having trouble coming up with a basis for how much flow is coming from the vent. There are no non-condensibles in the system, so I don't have a constant purge rate to use. The distillate is subcooled at the condenser outlet. (solvent b.p. is about 66°C and the exit temp is about 30°C)

Any thoughts on how to approach this?

[Bruce Ling]

I am working on an emissions estimate for a new batch process. One of the steps involves partially stripping solvent from a product solution by a single stage atmospheric distillation. I need to come up with an estimate of solvent loss from the condenser vent, and I'm having trouble coming up with a basis for how much flow is coming from the vent. There are no non-condensibles in the system, so I don't have a constant purge rate to use. The distillate is subcooled at the condenser outlet. (solvent b.p. is about 66°C and the exit temp is about 30°C)

Any thoughts on how to approach this?

Now that there are no non-condensable vapor in the system, why do you need vent? if do have, there only are solvent vapor volatilized into air....

[bhaskaran]

assuming non-condensable as air/nitrogen u can use partial pressure correlation with respect to temperature outlet to identify the exact losses

[Jiten_process]

dear uiucche94

If you have enough instruments to read flow and temperature parameters then it is not that difficult to find out the value u want. simple mass and energy balance will give u existing vapor loss through vent.

for e.g., if you know cooling water inlet/outlet temp., cooling water flow then this will give u the duty. use this to find out vapor loss through vent.

if you do not have proper instruments then you can see the datasheet of condenser and take out value of rated heat duty 'Q'. Use this value of 'Q' and carry out energy balance for solvent across the condenser for actual condition. You will get the solvent being vented through vent.

lets have others view...