Introductory Chemometrics Chemical Process Modeling Problem

Group work required; no collaboration between groups.  Show all work to receive credit

1.  Derive a multivariable regression equation that uses the average instantaneous conversion and average batch temperature to determine end of  reaction styrene concentration based on measured styrene results.

• Show the developed equation
• Plot the residuals as a function of styrene concentration
• Use p values, the coefficient of determination, and your residuals plot to comment on the validity of your styrene end of batch concentration prediction model

3.  Use the Flory-Huggins partial pressure worksheet to determine the maximum styrene latex concentration allowable under the OSHA 8 hour TWA guidelines at the end of the stripping process.  Assume that the final butadiene concentration is 500 ppm.

4.  Use the regression model developed in question 1 to predict styrene end-of-reaction concentrations for batch A123 with an Avg IC of 84.54 and an AvgRxTemp of 97.23.

5.  Use the batch A123 stripper worksheet to:

• Insert the starting styrene concentration determined in question 4.
• Fill in formulas for the steam and redox K's using the provided formulas.  (hint: steam lbs/min is the steam lbs for the current minute minus steam lbs for the previous minute; the redox rate is the redoxparts/min column).
• Fill in formulas for the combined K and the styrene concentration (hint: the styrene(n-1) is the styrene concentration from the line above)
• Plot the predicted styrene concentration as a function of time; use a logarithm scale for the styrene concentration.
• Find the reaction time required to bring the styrene concentration below the level at which the produced latex will not exceed OSHA TWA vapor exposure guidelines for styrene.

• What is meant by a latex?
• Explain what factors affect the vapor concentration of styrene above the latex; draw a picture to portray this.
• Look up and comment on the adverse health effects for styrene