Hassan ElBanhawi

About this Book (Preface):-

In an age when sophisticated computer technology has taken over the design, and often the operation, of distillation columns, the funda- mental practical aspects of distillation are rapidly becoming a forgotten art. Rules of thumb and McCabe-Thiele diagrams, once the main tools in the hands of the distillation practitioner, are rapidly being replaced by powerful mathematics. Yet, when a column experiences problems in the field, it is neither the computer nor the powerful mathematics that is able to reinstate trouble-free operation. Instead, it is the person in a pair of worn-out overalls with bags under his (or her) eyes from spending 16 hours on the plant the night before who finally solves the problem. This person rarely uses an electronic wizardry. His (or her) main tools are a good understanding of the plant and its equipment, a great deal of experience, good engineering judgment, and good systematic reasoning. This book is dedicated to that person— the distillation troubleshooter.

Well over a decade ago, after designing and revamping several distillation columns, I was given the duties of operating and starting up a distillation unit. My new boss had one simple warning: nine out of ten problems that occur in distillation equipment are not caused by poor design or inadequate theory, but by overlooking some practical guideline. I asked him if he knew of a text where such guidelines are documented. He made one request: if I ever found one, he would like to get a copy.

In the following decade, I spent a lot of time talking to people, collecting experiences and guidelines, combing the literature for published articles describing typical problems, and often calling or writing to their authors to discuss these problems. I converted their stories into notes, molded the notes into guidelines, turned the guidelines into chapters, and the chapters into a book. The purpose of this book is to show what has gone wrong in the past and to suggest means of preventing similar incidents in the future. Unfortunately, the process industries have short memories: people move on, and lessons are forgotten. It is my hope that the book retains these memories and makes the experience of several generations available to those who operate, start up, and design distillation and absorption equipment.

The suggestions and recommendations made in this book are given in good faith, but without any warranty. What works in one case may not work under even slightly different circumstances. In fact, you may even feel that some of the recommendations are not appropriate for your installation. Congratulations. Good chefs do not blindly follow recipes, even when they like the recipes. Likewise, you must critically examine any suggestions, recommendations, or ideas before utilizing them in a specific application.

If you have chosen a career as a designer or troubleshooter, you have selected a tough road. Many long, sleepless nights at the plant are ahead. You will spend many worrisome moments wondering whether your design is going to work. Many times your expectations will be shattered when a "fix" you could swear by does not make an ounce of difference. Your journey will be tiring and rough, yet exciting and strangely rewarding. Perhaps this book can help smooth your path.