Estimate amount of gas/liquid in a vessel

[wanabe gasman]

I am a first year chemical engineer
I am to estimate the amount (mass) of liquid and vapor in a number of vessels. Here are two examples:

1. I don't have the numbers yet, but was wondering about how best to estimate the mass of ethane and ethylene in our C2 splitter.
I was told that since this is for a homeland security study I would not have to get extremely accurate numbers however, I do not yet have a figure on how accurate they do want it. I am assuming very rough numbers will do for now. Therefore I don't feel the need to calculate the amount of liquid on each tray, but to rather assume a liquid level and composition of liquid and gas phase.
-Please respond if anyone has a method that my save me some time on this estimate.

2. PSA (Hydrogen purifiers): I don't know the density or a shape factor for the catalyst in this vessel since it is proprietary in nature.
-Is there a method for rough estimating the amount of gas in this vessel if I have the loading diagrams. All they provide is the weight of the loaded vessel.

Thank you all for sharing your experience and for your time.

 

[wanabe gasman]

Also, how do I find the compressibility factor Z. If I have the tower conditions. eg. 225psi, 115F, and composition.

Thank you

 

[EmmanuelTop]

With a homework for Homeland Security and straight to a public forum? Ts, ts, ts,...

Dejan IVANOVIC
Process Engineer, MSChE

 

[Latexman]

Jacob B,

Is there any old Process Hazard Analysis (PHA) laying around you can look at? Some of the PHA's I've helped prepare for wanted to know the inventory in each vessel. I'm not sure it will be in the format you need it, but it may be a big help. If not a PHA, has there been other past work/studies that may have the information you need. Otherwise, dig up the most recent simulation, the equipment drawings, the tray hydraulic calculations, the normal level settings, operating conditions, and start chipping away at it.

For the compressibility factor, that's been discussed here or in other fora several times. Use "Search". Under the title of this post, between "Forum" and "FAQs", you will find "Search". You should find some very detailed answers.

Good luck,
Latexman

To a ChE, the glass is always full - 1/2 air and 1/2 water.

 

[wanabe gasman]

OK. Thank you!