Design and Control of Reactive Distillation Process with Mixed Ethanol and Butanol Feed
Date Issued
2011
Date
2011
Author(s)
Tsai, Chen-Yu
Abstract
This work presents a feasible design for esterifications of mixed ethanol(EtOH) and n-butanol (BuOH) feed with acetic acid (HAc). NRTL-HOC thermodynamic model is used for modeling the vapor-liquid and vapor-liquid-liquid equilibrium. The reactions are catalyzed by using Amberlyst-15 catalyst. There are two alternative design regarding the alcohol mixtures as feed for reactive distillation. In the first design, separation of the mixture into pure alcohols goes first and esterifying with RD follows. In the second design, esterification by RD directly goes first and purifying the products goes next.For the second design,there are two design sequences to be considered: (1)Direct Sequence: all the reactants are fed into the bottom of the reactive distillation column, then the second column separates the water and ester mixture, the third stripping column then separates the EtAC and BuAC mixture . (2)Indirect Sequence: RD produces H2O and EtAc at the top and produces BuAc at the bottom. After comparing the total annual cost (TAC), indirect sequence is the best for steady state design.
The basic regulatory control loops of the overall process included four level loops and pressure loop for each column.
This research proposes a double temperature control loop in the reactive distillation column, the stripping column uses a single temperature control loop. Open loop sensitivity test is used to determine the position of the temperature controller, but the results show that this control structure does not perform well in disturbances. If using closed loop sensitivity test to determine the position of the temperature controller. The results show that this control structure is good at rejecting throughput and composition changes.
Subjects
reactive distillation
alcohol mixtures
esterification
direct sequence
indirect sequence
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-100-R98524060-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):a6afa01818951f34c76e0932f01bcf89