A short presentation of chemical engineering evolution

as guided by its paradigms

is exposed. The first paradigm-unit operations-has emerged as a necessity of systematization due to the explosion of chemical industrial applications at the end of 19th century. The birth in the late 1950s of the second paradigm-transport phenomena-was the consequence of the need for a deep

scientific knowledge of the phenomena that explain what happens inside of unit operations. In the second part of 20th century

the importance of chemical product properties and qualities has become essentially in themarket fights. Accordingly

it was requiredwith additional and even new fundamental approaches

and product engineering was recognized as the third paradigm. Nowadays chemical industry

as a huge materials and energy consumer

and with a strong ecological impact

couldn't remain outside of sustainability requirements. The basics of the fourth paradigm-sustainable chemical engineering-are now formulated.