2 replies to this topic

[hari prasad]

hey...i need help in calculating the reboiler duty and condenser duty for a distillation column...i do have the distillate,reflux liquid,reboiled and bottom product flow rate...just nt sure abt the material balance for the duty calculation?....the temperature is not specified at the condenser and reboiler section....i am assuming that it is a total condenser and partial reboiler...



Condenser
V=181.9
L=70.9
D=111
Xd=0.99

Reboiler
V-bar=180.9
L-bar=218.6
B=37.7
Xb=0.642

[riven]

OK
First what process material are you using. In a heat balance we need this for heat capacity.
Secondly what is the the data you provided eg [Xd: Mass fraction]
Thirdly are these the flows into outof or other for the condenser. I assume they are not inlet as getting liquid to a distillate condenser would be

[hari prasad]

A distillation system is proposed to take a feed stream of 3 L/min at 20°C containing
3-6 M1 of nitric acid laced with radioactive components and separate into two feed
streams. In order to comply with government disposal regulations, the distillate
system must have an acid concentration of no more than 10 ppm nitrate
concentration2. To become beneficial to other parts of the plant, the bottoms product
stream must have an acid concentration between 12 and 15 M.


So, as defined earlier my Xd value is the distillate mole fraction for the distillate product, D (mol/min). The vapour before entering the condenser is condensed and split into 2 parts. One is liquid entering the column back with an reflux ratio of 0.64 and another stream is the distillate product obtained which has to be less than 10ppm according to the requirement. The values for each of the phase around the condenser and reboiler has been calculated according to the given specification. My specified system is 4.5M of feed and and 13.5M of bottom product. Now i need to determine the condenser and reboiler duty required for the distillation column?