Unit operations concept

Chemical engineers have responded successfully for years to pressures to improve the efficiency and reduce the cost of chemical process operations and to design and construct chemical plants as safely and expeditiously as possible. In this regard, the unit operations concept has long been a useful organizing principle for the synthesis of chemical process flow sheets, while economies of scale and energy efficiency have dictated construction of the very large petrochemical plants that have dominated the scene for decades. 

Whereas the unit operation concept of chemical engineering asks for a clear separation of educt preparation. chemical reaction and product separation in different units, it is obvious that better conversion and selectivity might be achieved if educts arc added at the required amount and intermediates or products arc withdrawn from the place of reaction immediately Two general alternatives arc presently under discussion to achieve this goal, membrane methods and sorptive methods The basic difference is that membrane... 

An economical method of organizing much of the subject matter of chemical engineering is based on two facts (1) although the number of individual processes is great, each one can be broken down into a series of steps, called operations, each of which in turn appears in process after process (2) the individual operations have common techniques and are based on the same scientific principles. For example, in most processes solids and fluids must be moved heat or other forms of energy must be transferred from one substance to another and tasks like drying, size reduction, distillation, and evaporation must be performed. The unit-operation concept is this by studying systematically these operations themselves—operations that clearly cross industry and process lines—the treatment of all processes is unified and simplified. 

Process Technology 2—Systems—study of common process systems found in the chemical process industry, including related scientific principles. Includes study of pump and compressor systems, heat exchangers and cooling tower systems, boilers and furnace systems, distillation systems, reaction systems, utility system, separation systems, plastics systems, instrument systems, water treatment, and extraction systems. Computer console operation is often included in systems training. Emphasizes scale-up from laboratory (glassware) bench to pilot unit. Describe unit operation concepts solve elementary chemical mass/energy balance problems interpret analytical data and apply distillation, reaction, and fluid flow principles. 

Bird, Stewart and Lightfoot, Transport Phenomena (32). This has since had many imitators but it stands supreme in (a) its precedence in the growing recognition that the old unit operation concept was outdated and (b) in its development of a new intensity of mathematical approach to the subject. 

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