Innovative single step bioethanol dehydration in an extractive dividing-wall column

Abstract The large-scale production of bioethanol fuel requires energy demanding distillation steps to concentrate the diluted streams from the fermentation step and to overcome the azeotropic behavior of the ethanol–water mixture. The conventional separation sequence consists of three distillation columns performing several tasks with high energy penalties: pre-concentration of ethanol, extractive distillation and solvent recovery. Despite the novel recent developments in pervaporation and adsorption with molecular sieves, the industrial production of anhydrous bioethanol is still dominated by extractive distillation as the separation method of choice. This study proposes an innovative distillation setup – based on a novel extractive dividing-wall column (E-DWC) – that is able to concentrate and dehydrate bioethanol in a single step, by integrating all units of the conventional sequence into only one distillation column. In this work, a mixture of 10 wt% ethanol (100 ktpy plant) is concentrated and dehydrated using ethylene glycol as mass separating agent. Rigorous simulations were carried out in Aspen Plus, and for a fair comparison all alternatives were optimized using the reliable sequential quadratic programming (SQP) method. The results show that energy savings of 17%, and a similar decrease in CapEx, are possible for the novel E-DWC alternative, while using a significantly reduced footprint as compared to the conventional separation process.

[1]  G. Kaibel,et al.  Dividing wall columns: Fundamentals and recent advances , 2010 .

[2]  Anton A. Kiss,et al.  Dynamic optimization of a dividing-wall column using model predictive control , 2012 .

[3]  M. Balat,et al.  Progress in bioethanol processing , 2008 .

[4]  Costin Sorin Bildea,et al.  Reactive DWC leading the way to FAME and fortune , 2012 .

[5]  David Shan-Hill Wong,et al.  Controllability and energy efficiency of a high-purity divided wall column , 2007 .

[6]  Michael Bartholomew-Biggs,et al.  Nonlinear Optimization with Engineering Applications , 2008 .

[7]  Anton A. Kiss.  Separative reactors for integrated production of bioethanol and biodiesel , 2010, Comput. Chem. Eng..

[8]  R. M. Filho,et al.  Production of bioethanol and other bio-based materials from sugarcane bagasse: Integration to conventional bioethanol production process , 2009 .

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

[10]  W. Arlt,et al.  Hyperbranched polymers: new selective solvents for extractive distillation and solvent extraction , 2002 .

[11]  Carlos A Cardona,et al.  Fuel ethanol production: process design trends and integration opportunities. , 2007, Bioresource technology.

[12]  Leland M. Vane,et al.  Separation technologies for the recovery and dehydration of alcohols from fermentation broths , 2008 .

[13]  Lanyi Sun,et al.  Implementation of Ethanol Dehydration Using Dividing-Wall Heterogeneous Azeotropic Distillation Column , 2011 .

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

[15]  W. Kaminski,et al.  Renewable energy source—Dehydrated ethanol , 2008 .

[16]  A. K. Frolkova,et al.  Bioethanol dehydration: State of the art , 2010 .

[17]  Anton A. Kiss,et al.  Energy efficient control of a BTX dividing-wall column , 2011, Comput. Chem. Eng..

[18]  A. A. Kiss,et al.  Enhanced bioethanol dehydration by extractive and azeotropic distillation in dividing-wall columns , 2012 .

[19]  Anton A. Kiss,et al.  Understanding process intensification in cyclic distillation systems , 2011 .

[20]  Costin Sorin Bildea,et al.  A control perspective on process intensification in dividing-wall columns , 2011 .

[21]  Anton A. Kiss,et al.  Innovative dimethyl ether synthesis in a reactive dividing-wall column , 2012, Comput. Chem. Eng..

[22]  Ž. Olujić,et al.  Equipment improvement trends in distillation , 2009 .

[23]  Gade Pandu Rangaiah,et al.  A Simplified Procedure for Quick Design of Dividing-Wall Columns for Industrial Applications , 2009 .

[24]  Ilkka Turunen,et al.  A New Method for Synthesis of Thermodynamically Equivalent Structures for Petlyuk Arrangements , 2006 .

[25]  Toshinori Tsuru,et al.  Pervaporation of water/ethanol mixtures through microporous silica membranes , 2009 .

[26]  C. Black,et al.  Dehydration of Aqueous Ethanol Mixtures by Extractive Distillation , 1974 .

[27]  M. R. Wolf-Maciel,et al.  Anhydrous ethanol production by extractive distillation: A solvent case study , 2010 .

[28]  Salvador Hernández.  Analysis of Energy‐Efficient Complex Distillation Options to Purify Bioethanol , 2008 .

[29]  Paul T. Boggs,et al.  Sequential Quadratic Programming , 1995, Acta Numerica.

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

[31]  W. Geng,et al.  Selection of ionic liquids as entrainers for separation of (water + ethanol) , 2008 .

[32]  Eugeny Y. Kenig,et al.  Reactive Distillation in a Dividing Wall Column: Rate-Based Modeling and Simulation , 2007 .

[33]  Juan Gabriel Segovia-Hernández,et al.  Control properties of thermally coupled distillation sequences for different operating conditions , 2007, Comput. Chem. Eng..

[34]  Jan Harmsen,et al.  Process intensification in the petrochemicals industry: Drivers and hurdles for commercial implementation , 2010 .

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

[36]  A. Singh,et al.  Bioethanol technology: developments and perspectives. , 2002, Advances in applied microbiology.

[37]  Eugeny Y. Kenig,et al.  Dividing wall columns in chemical process industry: A review on current activities , 2011 .

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

[39]  Anton A. Kiss,et al.  Enhanced methanol recovery and glycerol separation in biodiesel production – DWC makes it happen , 2012 .

[40]  M. J. D. Powell,et al.  Variable Metric Methods for Constrained Optimization , 1982, ISMP.

[41]  Huajiang Huang,et al.  A review of separation technologies in current and future biorefineries , 2008 .

[42]  Sundergopal Sridhar,et al.  Dehydration of ethanol through blend membranes of chitosan and sodium alginate by pervaporation , 2004 .

[43]  Luis Puigjaner,et al.  Control and optimization of the divided wall column , 1999 .

[44]  Peter Lang,et al.  Batch extractive distillation as a hybrid process : separation of minimum boiling azeotropes , 2007 .

[45]  Subhash Bhatia,et al.  Process optimization studies for the dehydration of alcohol–water system by inorganic membrane based pervaporation separation using design of experiments (DOE) , 2010 .

[46]  Igor Dejanović,et al.  An Effective Method for Establishing the Stage and Reflux Requirement of Three-product Dividing Wall Columns , 2011 .