Complex Distillation Column By: Dr. Gerardo Ruiz LPPD UIC 10/22/2008

Complex Distillation Column Optimal complex column configuration is estimated to harness energy savings up to 70% Difference Point Equation Model Ternary System Examples Conclusion

Complex Distillation Column This complex column has two feed streams and three product streams Constant molar overflow is assumed in all sections of the column Constant volatility Isobaric process

Difference point equation The compositions and flow rates at the top of the section are know Doing a mass balance: Expressing the x n composition in terms of x n+1, by expanding it as a first order Taylor series

Difference Point Equation Rearranging the mass balance, and defining The difference point equation is:

Degree of Freedom Analysis Variables: *3 = 25 Equations: 9, equations (1) to (9) Design Specifications: 6 Problem Specification: 10 DOF=25 – 9 – = 0

Equations

Solution Strategy A design is feasible if and only if the composition profiles between the neighboring two sections intersect the composition at each end of column section must be known

Solution Strategy At the first section ( S 1 ):

Solution Strategy At the fourth section ( S 4 ):

Solution Strategy

S j : j=1, 2, 3, 4. i=1, 2, 3 Section S1S1 S2S2 S3S3 S4S4 Initial Cond.

Case of Study 1

Case of Study 2

Conclusion What we know: Ternary system i =k, Underwood, Ideal, Non-Ideal Single columns complex columns Quaternary system i =k, Underwood Single columns Single complex column What we dont know: Quaternary systems DOF 3c DOF 4c Ideal, Non-Ideal Single columns complex columns Partial condenser q 1 q 2, and q j 1 or 0

Thanks!!!!!! QUESTIONS????