Liquid Phase Dehydration of 1 - Butanol to Di - n - butyl ether Experimental Performan ce, Modeling and Simulation of Ion Exchange Resins as Catalysts María Ángeles Pérez - Maciá A questa tesi doctoral està subjecta a la llicència Reconeixement - NoComercial – SenseObraDerivada 3.0. Espanya de Creative Commons . Esta tesis doctoral está sujeta a la licencia Reconocimiento - NoComercial – SinObraDerivada 3.0. España de Creative Commons . Th is doctoral thesis is licensed under the Creative Commons Attribution - NonCommercial - NoD erivs 3.0. Spain License . Liquid Phase Dehydration of 1-Butanol to Di-n-butyl ether Experimental Performance, Modeling and Simulation of Ion Exchange Resins as Catalysts María Ángeles Pérez-Maciá Facultad de Química Departamento de Ingeniería Química LIQUID PHASE DEHYDRATION OF 1-BUTANOL TO DI-N-BUTYL ETHER. EXPERIMENTAL PERFORMANCE, MODELING AND SIMULATION OF ION-EXCHANGE RESINS AS CATALYSTS. Tesis Doctoral María de los Ángeles Pérez Maciá Dirigida por Dra. Montserrat Iborra y Dr. Roger Bringué Barcelona, 15 de septiembre de 2015 Programa de doctorado de Ingeniería y Tecnologías Avanzadas La Dra. MONTSERRAT IBORRA URIOS, profesora titular del Departamento de Ingeniería Química de la Universidad de Barcelona y el Dr. ROGER BRINGUÉ TOMÀS, profesor lector del mismo departamento, CERTIFICAN QUE: El trabajo de investigación titulado “LIQUID PHASE DEHYDRATION OF 1-BUTANOL TO DI-N-BUTYL ETHER. EXPERIMENTAL PERFORMANCE, MODELING AND SIMULATION OF ION-EXCHANGE RESINS AS CATALYSTS.” constituye la memoria que presenta la Ingeniera Química María de los Ángeles Pérez Maciá para aspirar al grado de Doctor por la Universidad de Barcelona. Esta tesis doctoral se ha llevado a cabo dentro del programa de Doctorado “Ingeniería y Tecnologías Avanzadas” en el Departamento de Ingeniería Química de la Universidad de Barcelona. Y para que así conste a los efectos oportunos, firman el presente certificado en Barcelona, 15 de septiembre de 2015. Dra. Montserrat Iborra y Dr. Roger Bringué Directores de la tesis doctoral i FOREWORD The objectives of the present thesis can be summarized in two main subjects which are clearly represented in the title of this thesis: Liquid phase dehydration of 1-butanol to di-n-butyl ether. Experimental performance, modeling and simulation of ion exchange resins as catalysts. In Chapters 1 and 2 the context of this thesis is defined and the materials and methods utilized in the subsequent chapters are introduced. The next three chapters deal with the first main objective of this thesis, Study of the liquid phase dehydration of 1-butanol to di-n-butyl ether over ion exchange resins. The performance of poly(styrene-divinylbenzene), P(S-DVB), ion exchange resins in the synthesis of di-n-butyl ether from the dehydration of 1-butanol in liquid phase is addressed in Chapter 3. This chapter also discusses the influence of typical 1-butanol impurities (isobutanol or ethanol and acetone, depending on the production route) on the dehydration process. Chapter 4 is devoted to the thermodynamic equilibrium of 1-butanol dehydration. The experimental values of the equilibrium constants for the dehydration of 1-butanol to di-n-butyl ether and for potential side reactions determined by direct measurement of the composition of the liquid mixture at equilibrium are presented. Chapter 5 is dedicated to the chemical kinetics of the dehydration of 1-butanol to di-n-butyl ether over Amberlyst 70, shedding some light on the mechanism of di-n- butyl ether formation. Furthermore, the inhibitory effect of water is investigated. The second general objective of this thesis, Modeling and simulation of ion exchange resin, has been developed in Chapters 6 and 7. Chapter 6 addresses the construction of a realistic model for P(S-DVB) networks. Furthermore, the relationship between the topology of highly crosslinked P(S-DVB) ion-exchange resins and their properties, especially the structural ones is studied by means of molecular dynamics simulations. Chapter 7 deals with the swelling of ion exchange resins in 1-butanol also by means of molecular dynamics simulations. In Chapter 8 a concise summary of the results of this thesis is presented together with suggestions for future work. Finally, at the end of this thesis an extended summary in Spanish can be found. iii OBJECTIVES (1) Check that sulfonic poly(styrene-divinylbenzene), P(S-DVB), ion exchange resins are suitable catalysts for the dehydration of 1-butanol to di-n-butyl ether, DNBE, in the liquid phase. (2) Evaluate the influence of the morphological characteristics of P(S-DVB) resins on the synthesis of DNBE and, based on these results, select the most appropriate resin for industrial use. (3) Study the influence that typical 1-butanol impurities have on the dehydration of 1-butanol. (4) Evaluate the equilibrium constant of the dehydration reaction of 1‐butanol to DNBE and main side reactions. (5) Perform a kinetic study of the dehydration of 1-butanol to DNBE over the thermostable ion exchange resin Amberlyst 70 and propose a kinetic equation with mechanistical base. (6) Develop a realistic atomistic model for the crosslinked network of P(S-DVB) ion exchange resins. The model must represent the heterogeneity of the macromolecular multi-chain networks. (7) Study the influence of the polymer topology on the microscopic properties of the resin using molecular dynamic simulations. (8) Study the swelling of ion-exchange resins in 1-butanol by means of molecular dynamics simulations. v TABLE OF CONTENTS 1. INTRODUCTION ............................................................................................................... 3 1.1. Oil based economy ................................................................................................................ 3 1.2. Reformulation of diesel fuel .................................................................................................. 4 1.3. Di-n-butyl ether (DNBE) ....................................................................................................... 4 1.3.1. DNBE synthesis route ................................................................................................. 5 1.3.1.1. 1-butanol synthesis ........................................................................................ 5 1.3.1.2. Dehydration of 1-butanol to DNBE .............................................................. 7 1.4. Ion exchange resins as catalysts ............................................................................................ 8 1.5. Role of computational chemistry in the understanding of materials properties .................. 10 Nomenclature .............................................................................................................................. 12 References ................................................................................................................................... 13 2. MATERIALS AND METHODOLOGY ......................................................................... 17 2.1. Chemicals ............................................................................................................................ 19 2.2. Catalysts .............................................................................................................................. 19 2.3. Experimental set up, analysis and procedure ....................................................................... 23 2.3.1. Experimental set up ................................................................................................... 23 2.3.2. Analysis ..................................................................................................................... 24 2.3.3. Procedure................................................................................................................... 24 2.4. Computational chemistry ..................................................................................................... 25 2.4.1. Molecular dynamic simulations ................................................................................ 25 2.4.1.1. Force Fields ................................................................................................. 27 2.4.1.2. Non-bonded interactions ............................................................................. 28 2.4.1.3. Temperature and pressure couplings ........................................................... 29 2.4.2. Sorption of solvents by polymer matrices ................................................................. 30 2.4.3. Free Energy Calculations .......................................................................................... 32 2.4.3.1. Free Energy Perturbation theory ................................................................. 32 2.4.3.2. Thermodynamic Integration ........................................................................ 33 2.4.3.3. Non-equilibrium method ............................................................................. 34 Nomenclature .............................................................................................................................. 36 References ................................................................................................................................... 39 vi 3. SYNTHESIS OF DI-N-BUTYL ETHER FROM 1-BUTANOL OVER ACIDIC ION EXCHANGE RESINS ...................................................................................... 41 3.1. Introduction ........................................................................................................................