The first thought for description of Chemical Engineering is, as the name implies, application of knowledge of natural and life sciences in which chemistry being stood first on the list with an engineering approach. But, the first description in literature was termed by American Institute of Chemical Engineers (AIChE) in 1950. According to the Institute:

“Chemical Engineering is the profession in which knowledge of mathematics, chemistry, and other natural sciences gained by study, experience, and practice is applied with judgments to develop economic ways of using materials and energy for the benefit of mankind.”

This description was renewed in 1970-80’s as follows:

“Chemical Engineering is a discipline which investigates the changes occurring on composition, state and energy of materials, and devices producing those changes in accordance with the perception of engineering, economy and interrelation of mankind.”

The 21^st century definition of Chemical Engineering is:

“one of the versatile engineering discipline deals with the development and application of the most economic, environmentally friendly micro- and macro-processes in which physical and/or chemical structure and energy concept of materials are changed.”

Chemical Engineering is divided into two main sections namely “Process Engineering” and “Product Engineering”. But, according to developed process or desired product, currently several concepts are occurred inside this science. Some of these new areas are:

• Biotechnology

• Bioengineering

• Biochemical Engineering

• Enzyme Engineering

• Protein Engineering

• Genetic Engineering

• Fuel Cells

• Renewable Energy Resource

• Nanotechnology

• Waste Management

As it is predicted from both its definition and subsections, the characteristics of a “good” chemical engineer are:

• A broad background of knowledge on chemistry, physics, mathematics, biology, and computer sciences,
• An ability to function on multi-disciplinary-teams,
• An ability to identify, formulate, design and operate new projects,
• A recognition of sustainable development and environmentally-conscious mentality,
• An ability to make economical analysis and to interpret their results.

Because of its multi-disciplinary structure, the employment areas of chemical engineers are also very wide. A Chemical Engineer works under different responsibilities in industrial plants, private or public institutions of several different sectors: