Selection of methods for the properties of vinyl chloride
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This post was last edited by Lin Xuefeng on 2015-11-12 at 15:21. Based on the basic principles for selecting physical property methods, what physical property method should be used, according to everyone’s opinion, for producing vinyl chloride via the calcium carbide route (acetylene and hydrogen chloride)? In the calcium carbide process, the temperature does not exceed 200 degrees, and the pressure does not exceed 6 kilograms. Which property method should be used to produce vinyl chloride via the ethylene route (ethylene and chlorine)? The temperature in the ethylene process does not exceed 500 degrees, and the pressure does not exceed 6 kilograms. My view is on activity coefficient equations, such as NRTL or UNIQUAC, and so on. I would appreciate it if the experts could share their views.
Equation of state for high-pressure hydrocarbon applications
If you’re not under much pressure, you can simply use a regular equation of state.
The opinion upstairs is correct! Generally speaking, the activity coefficient method is used for non-ideal solutions; in this case, since the pressure is not high, the PR equation will suffice, or the SRK equation can also be used – you might give it a try!
This post was last edited by Lin Xuefeng on 2015-11-16 at 16:17. Isn’t the equation of state used for non-polar substances? Hydrogen chloride and vinyl chloride are polar. I know that the help system can narrow down the options, but how can I roughly determine which type of property method to use before it does so?
This post was last edited by Lin Xuefeng on 2015-11-16 at 16:18. According to the textbook, the activity coefficient method is used for polar substances (polar systems), and my raw materials and products are polar systems. Although I can see the answer, I’m still not clear about it. Could you please explain again why the equation of state was chosen? Thank you.
Activity coefficients are generally used to express deviations in liquids via activity, while for gases with some polarity, fugacity can be taken into account using an EOS.
The reaction process takes place in a gaseous state and is described by the EOS equation; but since the distillation process involves liquid vinyl chloride, is it necessary to use an activity coefficient equation instead?