Product Engineering: Molecular Structure and Properties PDF

Preface

Engineers make useful things for people, and chemical engineers do it with chemistry. The two main tasks are what we should make, or product engineering, and how we should make it, or process engineering. Both topics are important if we are to make with skill what people want. The current chemical engineering curriculum concentrates on the manufacturing process, which leads to efficient production, reduced cost, and improved safety. However, new and improved products are needed periodically to rejuvenate the industry, and to help customers lead better lives. There was a time that consumers waited eagerly for the introduction of miraculous new chemical products that transformed their lives, such as celluloid, nylon, penicillin, synthetic rubber, Teflon, and Kevlar. But, for the past decade, information technology has held center stage and captured the attention of the public, with new products such as the personal computer, cellular telephone, word processors, spreadsheets, and the Internet. Ambitious new engineering graduates always seek opportunities to demonstrate their prowess, to innovate products with high growth and profit and to avoid stagnant commodities such as sulfuric acid and common salt. The business landscape is littered with the wreckage of once-successful companies that focused exclusively on cost cutting and neglected the development of new products.

It is sometimes said that chemical engineers wait for the chemists to invent new products, and then are summoned to manufacture them in quantity with economy and safety. Indeed, in many companies, the most ambitious new chemical engineering graduates often gravitate toward the process departments, as their education and curriculum seem more relevant to solving process problems. But neither is there anything in the curriculum of chemists that teaches them how to design products. Thomas Midgley, Jr. invented both tetraethyl lead and Freon, two of the most celebrated products in the 20th century, but he only had a bachelor's degree in mechanical engineering, and he had to learn on his own the chemistry of structure–property relations. This exclusive concentration on processes also cuts off the chemical engineers from exposure to the desires and fears of society, and hinders their development into fully fledged policy makers and organizational leaders.

Many chemical engineers currently work in industry and academia on solving product engineering problems, and their work would be much more productive if they were given appropriate toolboxes of theories that are generally applicable, powerful new computer hardware and software, and triumphant cases of historical developments to inspire and show the winning ways. In the last few years, a number of universities in the United States and Europe have started courses and degree programs in product engineering. There are many different approaches to the course contents, depending on the resources of these pioneering teachers. An effective method is to introduce the subject by the historic case method. This shows the patterns of past successes, which methods were fruitful, and which paths were barren. A second method is to provide useful tools in the search for materials that possess the desired properties, as well as ways to modify materials to improve their properties. A third method of teaching is by doing a product design project, perhaps in parallel with the traditional process design project, which must take into consideration market needs and safety and environmental impacts.

This book takes the approach that these three methods all teach valuable lessons, and is thus divided into three parts. Part I describes inspiring historic cases of product innovations, with a focus on the creative product engineering work involved. It is largely descriptive, and provides justifications for the analytical tools and synthesis efforts to follow. Part II covers molecular structure–property relations, which provides the analytical tools to search for materials with desired properties, as well as ways to modify materials to improve their properties. The subject of molecular structure–property relations has been tremendously enhanced by powerful new computer methods. Part III challenges the future product engineers to understand the design goals, and to satisfy both market demand and public acceptance. The culmination is a design project for the students to exercise creativity, and to make trade-offs in synthesizing numerous elements together to make a successful product: What is the market demand for a product and what properties should it have? What may be the product composition and manufacturing technology? What are the safety and environmental problems from extraction to final disposal? What may be the financial reward for launching this product?

New products are urgently needed by the public and the chemical processing industries; and perhaps the understanding and skills of molecular structure and properties, combined with modern computer software and the Internet, would help to give a boost to creativity. In the terminology of Thomas Kuhn, a paradigm is a galaxy of concepts and tools that can solve important problems, becomes widely taught in universities, and generates meaningful research challenges. Perhaps product engineering and molecular structure–property relations can follow the advances of unit operations and transport phenomena, and become the Third Paradigm of Chemical Engineering.

Shortly after the publication of the Amundson Report on the future of chemical engineering in 1989, Edward Cussler and I discussed the need for a book on products. Subsequently, he became the pioneer and coauthored the first modern book in product design. Neither of us has ever designed a product that became a winner in the marketplace. It is customary in our profession that those who write design books have never designed a chemical plant or an oil refinery, but those who have done so do not write. I am indebted to many friends who have participated in the design of successful products and who are willing to share their experiences: Harold Chung told me about the exciting story of guided-missile fuel, Mauricio Futran and San Kiang told me about the history and development of taxol, and Bob Langer told me about controlled drug delivery.