The application of engineering principles to conceive, design, develop, operate, or use processes and products based on chemical and physical phenomena. The chemical engineer is considered an engineering generalist because of a unique ability (among engineers) to understand and exploit chemical change. Drawing on the principles of mathematics, physics, and chemistry and familiar with all forms of matter and energy and their manipulation, the chemical engineer is well suited for working in a wide range of technologies.

Although chemical engineering was conceived primarily in England, it underwent its main development in America, propelled at first by the petroleum and heavy-chemical industries, and later by the petrochemical industry with its production of plastics, synthetic rubber, and synthetic fibers from petroleum and natural-gas starting materials. In the early twentieth century, chemical engineering developed the physical separations such as distillation, absorption, and extraction, in which the principles of mass transfer, fluid dynamics, and heat transfer were combined in equipment design. The chemical and physical aspects of chemical engineering are known as unit processes and unit operations, respectively.

Chemical engineering now is applied in biotechnology, energy, environmental, food processing, microelectronics, and pharmaceutical industries, to name a few. In such industries, chemical engineers work in production, research, design, process and product development, marketing, data processing, sales, and, almost invariably, throughout top management. Biochemical engineering Biomedical chemical engineering Biotechnology