以下内容来自《Elementary Principles of Chemical Processes》第一章，此书是美国某大学化学工程专业的第一门专业课“Material and Energy Balances”的教材。
Last May, thousands of chemical engineeringseniors took their last final examination, attended their graduation ceremonies, flipped their tassels and threw their mortarboards in the air, enjoyed their farewell parties, said goodbye to one another and promised faithfully to stay in touch, and headed off in an impressive variety of geographical and career directions.
Since you bought this book, you are probably thinking about following in the footsteps of those graduates—spending the next few years learning to be a chemical engineer and possibly the next 40 applying what you learn in a career. Even so, it is a fairly safe bet that, like most people in your position, you have only a limited idea of what chemical engineering is or what chemical engineers do. A logical way for us to begin this book might therefore be with a definition of chemical engineering.
Unfortunately, no universally accepted definition of chemical engineering exists, and almost every type of skilled work you can think of is done somewhere by people educated as chemical engineers. Providing a definition has recently become even more difficult as university chemical engineering departments have morphed into departments of chemical and biomolecular engineering or chemical and materials engineering or chemical and environmental engineering. We will therefore abandon the idea of formulating a simple definition, and instead take a closer look at what those recent graduates did either immediately after graduation or following a well-earned vacation. We will also do some speculating about what they might do several years after graduating, based on our experiences with graduates from previous classes. Consider these examples and see if any of them sound like the sort of career you can see yourself pursuing and enjoying.
? About 45% of the class went to work for chemical, petrochemical, pulp and paper, and polymer (plastics) manufacturing firms.
? Another 35% went to work for government agencies and design and consulting firms (many specializing in environmental regulation and pollution control), companies in fields such as microelectronics and information technology that have not been traditionally associated with chemical engineering, and firms specializing in emerging areas such as biotechnology and sustainable development (development that addresses economic, ecological, cultural, and political considerations).
? About 10% of the class went directly into graduate school in chemical engineering. The master’s degree candidates will get advanced training in traditional chemical engineering areas (thermodynamics, chemical reactor analysis and design, fluid dynamics, mass and heat transfer, and chemical process design and control) and emerging areas such as biotechnology, biomedicine, materials science and engineering, nanotechnology, and sustainable development. They will have access to most of the jobs available to the bachelor’s degree holders plus jobs in those emerging areas that require additional training. The doctoral degree candidates will get more advanced training and work on major research projects, and in four to five years most will graduate and either go into industrial research and development or join university faculties.
? A small number were drawn to entrepreneurship, and with in a few years after graduation will start their own companies in areas that might or might not have anything to do with their college backgrounds.
?The remaining 10% of the class went into graduate school in areas other than engineering, discovering that their chemical engineering backgrounds made them strongly competitive for admission to top universities. Several who took biology electives in their undergraduate programs went to medical school. Others went to law school, planning to go into patent or corporate law, and still others enrolled in Master of Business Administration programs with the goal of moving into management in industry.
? One graduate joined the Peace Corps for a two-year stint in East Africa helping local communities develop sanitary waste disposal systems and also teaching science and English in a rural school. When she returns, she will complete a Ph.D. program in environmental engineering, join a chemical engineering faculty, write a definitive book on environmental applications of chemical engineering principles, quickly rise through the ranks to become a full professor, resign after 10 years to run for the United States Senate, win two terms, and eventually become head of a large and highly successful private foundation dedicated to improving education in economically deprived communities. She will attribute her career successes inpart to the problem-solving skills she acquired in her undergraduate training in chemical engineering.
? At various points in their careers, some of the graduates will work in chemical or biochemical or biomedicalor material science laboratories doing research and development or quality engineering, at computer terminals designing processes and products and control systems, at field locations managing the construction and startup of manufacturing plants, on production floors supervising and troubleshooting and improving operations, on the road doing technical sales and service, in executive offices performing administrative functions, in government agencies responsible for environmental and occupational health and safety, in hospitals and clinics practicing medicine or biomedical engineering, in law offices specializing in chemical process-related patent work, and in classrooms teaching the next generation of students.
The careers just described are clearly too diverse to fall into a single category. They involve disciplines including physics, chemistry, biology, environmental science, medicine, law, applied mathematics, statistics, information technology, economics, research, design, construction, sales and service, production supervision, and business administration. The single feature they have in common is that chemical engineers can be found doing them. Some of the specific knowledge needed to carry out the tasks will be presented later in the chemical engineering curriculum, and most of it must be learned after graduation. There are, however, basic techniques that have been developed for setting up and attacking technical problems that apply across a broad range of disciplines. What some of these techniques are and how and when to use them are the subjects of this book.