Editing Chemical engineering (section)

==Concepts==
{{chemical engineering}}

Chemical engineering involves the application of several principles. Key concepts are presented below.

===Plant design and construction===
Chemical engineering design concerns the creation of plans, specifications, and economic analyses for [[pilot plant]]s, new plants, or plant modifications. Design engineers often work in a consulting role, designing plants to meet clients' needs. Design is limited by several factors, including funding, government regulations, and safety standards. These constraints dictate a plant's choice of process, [[Chemical reactor materials selection|materials]], and equipment.{{sfn|Towler|Sinnott|2008|pp=2–3}}

Plant construction is coordinated by [[project engineering|project engineers]] and project managers,<ref>Herbst, Andrew; Hans Verwijs (Oct. 19-22).                              
                   "Project Engineering: Interdisciplinary Coordination and Overall Engineering Quality Control". Proc. of the Annual IAC conference of the American Society for Engineering Management 1 ({{ISBN|9781618393616}}): 15–21</ref> depending on the size of the investment. A chemical engineer may do the job of project engineer full-time or part of the time, which requires additional training and job skills or act as a consultant to the project group. In the USA the education of chemical engineering graduates from the Baccalaureate programs accredited by [[ABET]] do not usually stress project engineering education, which can be obtained by specialized training, as electives, or from [[graduate programs]]. Project engineering jobs are some of the largest employers for chemical engineers.<ref>{{cite web|title=What Do Chemical Engineers Do?|url=http://chemistry.about.com/od/chemistrystudentfaqs/f/chemeng.htm|access-date=2015-08-23|archive-date=2014-05-02|archive-url=https://web.archive.org/web/20140502004955/http://chemistry.about.com/od/chemistrystudentfaqs/f/chemeng.htm|url-status=dead}}</ref>

===Process design and analysis===
{{main|Process design}}

A unit operation is a physical step in an individual chemical engineering process. Unit operations (such as [[crystallization]], [[filtration]], [[drying]] and [[evaporation]]) are used to prepare reactants, purifying and separating its products, recycling unspent reactants, and controlling energy transfer in reactors.{{sfn|McCabe|Smith|Hariott|1993|p=4}} On the other hand, a unit process is the chemical equivalent of a unit operation. Along with unit operations, unit processes constitute a process operation. Unit processes (such as [[nitration]], hydrogenation, and [[oxidation]] involve the conversion of materials by [[biochemical]], [[thermochemical]] and other means. Chemical engineers responsible for these are called [[process engineer]]s.{{sfn|Silla|2003|pp=8–9}}

Process design requires the definition of equipment types and sizes as well as how they are connected and the materials of construction. Details are often printed on a [[Process Flow Diagram]] which is used to control the capacity and reliability of a new or existing chemical factory.{{cn|date=April 2025}}

[[Education for Chemical Engineers|Education for chemical engineers]] in the first college degree 3 or 4 years of study stresses the principles and practices of process design. The same skills are used in existing chemical plants to evaluate the [[Economics#Economic efficiency|efficiency]] and make recommendations for improvements.<ref>{{Cite web |title=Chemical Engineering |url=https://www.acs.org/careers/chemical-sciences/areas/chemical-engineering.html |access-date=2025-04-29 |website=American Chemical Society |language=en}}</ref>

===Transport phenomena===
{{main|Transport phenomena}}

Modeling and analysis of transport phenomena is essential for many industrial applications. Transport phenomena involve [[fluid dynamics]], [[heat transfer]] and [[mass transfer]], which are governed mainly by [[momentum transfer]], [[energy transfer]] and transport of [[chemical species]], respectively. Models often involve separate considerations for [[macroscopic scale|macroscopic]], [[microscopic scale|microscopic]] and [[molecular]] level phenomena. Modeling of transport phenomena, therefore, requires an understanding of applied mathematics.{{sfn|Bird|Stewart|Lightfoot|2002|pp=1–2}}