Implementation of Ethanol Dehydration Using Dividing-Wall Heterogeneous Azeotropic Distillation Column

In this article, the design and optimization procedures of a dividing-wall column for heterogeneous azeotropic distillation (DWC-A) using cyclohexane as an entrainer for ethanol dehydration are investigated. The proposed procedures can detect the optimal values of the design variables and thereby guarantee the minimum energy requirements, which is related to the minimum CO2 emissions and the lowest total annual cost (TAC). Since ethanol and water form an azeotrope under atmosphere pressure, a conventional heterogeneous azeotropic distillation sequence (CHADS), including an azeotropic column and a recovery column, is usually used to perform the ethanol dehydration process. However, due to high energy requirements and equipment investments of CHADS, the TAC is at a relatively high level. DWC-A can be used to eliminate the condenser of the second column and decrease the degree of back-mixing. Both CHADS and DWC-A are simulated with Aspen Plus®, and the results show that DWC-A has an energy saving of 42.17% and the TAC reduction of 35.18% along with higher thermodynamic efficiency and reduction in greenhouse gas emissions.

[1]  B. Suphanit,et al.  Exergy loss analysis of heat transfer across the wall of the dividing-wall distillation column , 2007 .

[2]  V. Gomis,et al.  Dehydration of ethanol using azeotropic distillation with isooctane , 2007 .

[3]  James M. Douglas,et al.  Conceptual Design of Chemical Processes , 1988 .

[4]  Peter Mizsey,et al.  Rigorous Comparative Study of Energy-Integrated Distillation Schemes , 1996 .

[5]  J. Segovia-Hernández,et al.  Reactive dividing wall distillation columns: Simulation and implementation in a pilot plant☆ , 2009 .

[6]  Ž. Olujić,et al.  Reducing CO2 emissions of internally heat-integrated distillation columns for separation of close boiling mixtures , 2006 .

[7]  I-Lung Chien,et al.  Design and Control of a Complete Heterogeneous Azeotropic Distillation Column System , 2004 .

[8]  Francesca Ferrara,et al.  Design of heat integrated distillation systems for a light ends separation plant , 2007 .

[9]  W. Luyben.  Distillation Design and Control Using Aspen Simulation , 2006 .

[10]  Michael A. Schultz,et al.  Reduce Costs with Dividing-Wall Columns , 2002 .

[11]  William L. Luyben,et al.  Control of a multiunit heterogeneous azeotropic distillation process , 2006 .

[12]  Sten Bay Jørgensen,et al.  Multiple Steady States in Heterogeneous Azeotropic Distillation Sequences , 1998 .

[13]  Cristofer Bravo-Bravo,et al.  Extractive Dividing Wall Column: Design and Optimization , 2010 .

[14]  Hans Becker,et al.  Partitioned Distillation Columns -- Why, When & How , 2001 .

[15]  Michael F. Doherty,et al.  Design and minimum reflux for heterogeneous azeotropic distillation columns , 1989 .

[16]  R. Agrawal,et al.  Are Thermally Coupled Distillation Columns Always Thermodynamically More Efficient for Ternary Distillations , 1998 .

[17]  William L. Luyben,et al.  Distillation Design and Control Using AspenTM Simulation: Luyben/Distillation Design and Control Using Aspen Simulation , 2006 .

[18]  I. A. Furzer.  Synthesis of entrainers in heteroazeotropic distillation systems , 1994 .

[19]  Arthur W. Westerberg,et al.  Temperature-heat diagrams for complex columns. 2. Underwood's method for side strippers and enrichers , 1989 .

[20]  Anton A. Kiss,et al.  REACTIVE DIVIDING-WALL COLUMNS—HOW TO GET MORE WITH LESS RESOURCES? , 2009 .

[21]  Wolfgang Marquardt,et al.  Analysis and Conceptual Design of Ternary Heterogeneous Azeotropic Distillation Processes , 2002 .

[22]  Ikuho Yamada,et al.  Azeotropic Distillation Process with Vertical Divided-Wall Column. , 2001 .

[23]  F. Petlyuk.  Thermodynamically Optimal Method for Separating Multicomponent Mixtures , 1965 .

[24]  Ljubica Matijašević,et al.  Dividing wall column—A breakthrough towards sustainable distilling , 2010 .

[25]  Thomas E Marlin,et al.  Process Control , 1995 .

[26]  V. Gomis,et al.  Application of Isooctane to the Dehydration of Ethanol. Design of a Column Sequence To Obtain Absolute Ethanol by Heterogeneous Azeotropic Distillation , 2003 .

[27]  Shyan-Shu Shieh,et al.  Plant-wide design and control of acetic acid dehydration system via heterogeneous azeotropic distillation and divided wall distillation , 2008 .

[28]  I. Chien,et al.  Combined Preconcentrator/Recovery Column Design for Isopropyl Alcohol Dehydration Process , 2007 .

[29]  M. Emtir,et al.  Rigorous simulation of energy integrated and thermally coupled distillation schemes for ternary mixture , 2001 .

[31]  Juan Gabriel Segovia-Hernández,et al.  Reducing energy consumption and CO2 emissions in extractive distillation , 2009 .

[32]  David Shan-Hill Wong,et al.  Design and control of transesterification reactive distillation with thermal coupling , 2008, Comput. Chem. Eng..

[33]  Anton A. Kiss,et al.  Comparison of Control Strategies for Dividing-Wall Columns , 2010 .

[34]  Cheng-Ching Yu,et al.  Design and control for recycle plants with heat-integrated separators , 2004 .

[35]  F. Xiao.  CO_2 emission reduction through energy integration , 2006 .

[36]  Juan Gabriel Segovia-Hernández,et al.  Reduction of Energy Consumption and Greenhouse Gas Emissions in a Plant for the Separation of Amines , 2008 .