Preface

The distillation process has many applications, the most important of which is purifying water.

Water is one of the most significant resources in the world. Freshwater is of particular importance because it is increasingly being polluted, threatening human and animal health. One of the most common and effective techniques to purify and maintain the supply of freshwater is distillation, which separates dissolved solids or excess salt, other minerals, and impurities from seawater. Like distillation, membrane distillation uses a hydrophobic membrane between the feed and the condenser, allowing only solvent vapor to pass through. Thus, it has some advantages over conventional desalination by distillation. In the first section, this book presents some principles and studies of desalination by solar and membrane distillation.

Reactive distillation is a process in which chemical reactions and separation by distillation occur in a single operation. Reactive distillation can be used, for example, to separate azeotropic mixtures in equilibrium-limited reactions. Other advantages of reactive distillation are the reduction of investment and operational costs, increased efficiency of the separation process efficiency and improvement of reaction selectivity Reactive distillation has been studied a lot in the last decades and researchers have proposed some modifications to the process, such as adding a reactive divided wall distillation column. In the second section, this book discusses reactive distillation.

A good way to better understand a process is to represent the process with a mathematical model based on conservation laws (mass, energy, and momentum), constitutive relationships, and empirical equations. The proposed mathematical model must be validated by experimental data to prove that it accurately represents the process behavior. Once there is a good mathematical model, it is possible to run simulations. After obtaining a good representation of process behavior, an optimization step can be carried out. This book presents some cases of mathematical modeling, simulation, and optimization of the distillation process. It also includes studies on the application of artificial neural networks in desalination and reactive distillation.

> **Vilmar Steffen** Departamento acadêmico de Engenharias, Universidade Tenológica Federal do Paraná, Francisco Beltrão, Paraná, Brazil
