What Is Chemical Engineering

WHAT IS CHEMICAL ENGINEERING? DEFINITION OF CHEMICAL ENGINEERING What does the word ‘chemical engineering’ mean? What would a person, who never heard of these words, think of? From the words, itself let’s try to deduce a definition. ‘Chemical’ is a general word used to refer to a wide variety of substances. Examples of chemicals are alcohols, acids, bases, powders or any chemical reagent that may be used in laboratories. ‘Engineering’ is a term associated to applying a specific scientific idea or mathematical technique to obtain an answer for practical problems. Examples of practical problems are ‘Determine the mass of a liquid inside a container.’, and ‘How much water and salt must be added to produce a homogeneous solution of certain composition?’. Engineering aims to answer these kinds of questions. With these understanding of ‘chemical’ and ‘engineering’, one may think that chemical engineering is all about finding how to apply specific chemicals and their properties in practical problems. Being a chemical engineer, that definition is too restrained. According to McCabe, Smith and Harriot, chemical engineering deals with transforming raw materials to useful products. Based on how I’ve studied chemical engineering, this is the best definition. The scope of chemical engineering is mainly on industrial processes and on how these processes transforms raw materials to useful products. It is all about understanding and manipulating these processes in order to produce the desired product. This is achieved by using scientific principles and mathematical techniques. WHAT AND WHERE THEY WORK The term ‘industrial’ brings into mind two things: (1) Chemical plant and (2) large scale production. The chemical engineer therefore resides in a chemical plant and handles large amounts of materials. This is where all industrial processes take place and process large amounts of raw material. Exactly what are these industrial processes? How do they transform these raw materials? These industrial processes can be broken down to two types based on their function: (1) unit operations and (2) unit processes. Unit operations are physical treatments undergone by raw materials. Its purpose is to separate certain components from the raw material. Unit processes are in essence chemical reactions. Its main aim is to produce the useful product. Below is a simplified diagram of a chemical plant. Raw mat’l Unit Operations

Unit Processes

Unit Operations

Processed products

Unit operations are at the start of the plant because different components are usually found in the raw material. These components if not removed may cause the succeeding operation to not function. Various physical treatments are used to separate the different kinds of components. The treated raw materials become more amenable to the chemical reaction. Once this is accomplished the next step is unit processes. Unit processes make the material undergo a chemical reaction thus changing their composition and producing a useful product. The product from the unit process usually comes out with some unwanted components and therefore requires further separation. Unit operations are needed to further separate the exiting material.

DUTIES AND RESPONSIBILITIES Chemical engineering is all about processing raw materials to finished useful products. The field requires scientific principles and mathematical techniques applied in the chemical plant to process large amounts of raw materials. The chemical engineer must understand each of these physical and chemical processes to efficiently operate the plant. As a result, chemical engineers are responsible for the production of the wide variety of products found in society. It is our duty to properly produce these products for the benefit of society.