Chemical processes are the heart of any chemical industry. Studying these chemical processes as a whole is not an easy task. So for simplicity, these chemical processes are devided further to simple operations and processes. This simplification not only helps chemical engineers to study and design each piece of equipment for the process but also helps in the rectification of problems.
The importance of unit operations in chemical engineering is so much that without unit operations we can not imagine chemical engineering.
So in this article, I have described unit operations and their types.
What is Unit Operation?
Unit operation is the basic step in any chemical process. In unit operations, physical changes take place in the material.
Flowing of fluid, Heating of liquid, separation of two components are some examples of these basic steps. Chemical processes consist of several of these unit operations.
As mechanical engineers are concerned with machinery and scientists to work on reactions, There is a requirement of a bridge between them. So chemical engineering is born. Chemical engineers work on the process of conversion of raw materials to desired products by reactions determined by scientists with the help of mechanical engineers who work on the machine side.
So none of the two ends, Scientists and Mechanical Engineers study different steps required in a chemical process. These steps in the chemical process also called unit operations are studied and developed only by chemical engineers.
Importance of Unit Operation
- Unit operations simplify the chemical process
- Unit operations help to understand different aspects of chemical engineering
- Unit operations make the study of the whole process easier
- Unit operations help us to make the process more efficient
Unit Operation vs Unit Process
Unit operations and unit processes are two different types of steps that combined help us to completely define any chemical process.
Unit processes are a step in any chemical process in which physical, as well as chemical changes, take place in the material.
Here the main difference between unit operations and unit processes comes into the picture. Unit operations only involve physical changes in the material where the chemical process also incorporates chemical changes.
Most unit processes are part of the curriculum of science students. Unit processes are not generally studied in depth by chemical engineers. Chemical engineers study unit operations in depth.
Types of Unit Operations
Unit operations are classified into four groups according to their effect on different parameters such as pressure, temperature, composition and, size, and shape.- Fluid flow operations - In fluid flow operations properties such as pressure, velocity, and momentum change take place. Important fluid flow equipment is a pump, fan, blower, compressor, pipe, fittings, etc.
- Heat transfer operations - In heat transfer operations properties such as temperature and energy change takes place. Important heat transfer equipment is a heat exchanger, reboiler, condenser, evaporator, etc.
- Mass transfer operations - In mass transfer operations properties such as composition and concentration change takes place. Important heat transfer equipment is plate tower, packed column, venturi scrubber, falling film column, etc.
- Mechanical operations - Finally in mass transfer operations properties such as size and shape change takes place. Mechanical operations revolve around solids. Important mechanical operation equipment is crushers, screens, mixers, filters, etc.
Here is one video of Chemical Engineering Guy regarding Unit Operations: