Editing Chemical engineering (section)

===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>