01-28-09

Write a model on Excel which will use the generic cubic equation of state to
solve for P, V, or T. This model should work for any of the cubic equations
of state listed in Table 3.1. Note, you should only have to input the system
conditions and substance specific constants. Write a brief paper explaining:
a) how the model works €“ list relevant equations, b) what assumptions were
made, c) what are the limitations of the model and when should each CEOS be
used. Note this write-up must be less than two pages with 1.5 line spacing.

Use the model developed to solve the following problem.

Polypropylene (one of the largest commodity polymers in the world) is
produced by the gas-phase polymerization of propylene over a Ziegler-Natta
catalyst. The two most important variables controlling the resultant polymer
properties are the temperature and the concentration of propylene. These
reactors typically run at about 120 °C and 15 bars. Under these conditions
determine the concentration (in mol/liter) of propylene in the reactor using
the SRK CEOS. Plot the concentration of propylene versus pressure (at 120
°C) over a range of 10 bars to 20 bars using both the SRK CEOS and the ideal
gas equation. Is the ideal gas equation sufficient? Why or why not?