UNIT PROCESSES

INTRODUCTION

Every industrial process is designed to produce a desired product from a variety of starting raw materials using energy through a succession of treatment steps integrated in a rational fashion. The treatments steps are either physical or chemical in nature.

                

Energy is an input to or output in chemical processes.

The layout of a chemical process indicates areas where:

1.                       raw materials are pre-treated                
2.                       conversion takes place
3.                       separation of products from by-products is carried out
4.                      refining/purification of products takes place
5.                     entry and exit points of services such as cooling water and steam

Units process: A chemical process consists of a combination of chemical reactions such as synthesis, calcination, ion exchange, electrolysis, oxidation, hydration and operations based on physical phenomena such as evaporation, crystallization, distillation and extraction

A chemical process is therefore any single processing unit or a combination of processing units used for the conversion of raw materials through any combination of chemical and  physical treatment changes into finished products. Unit processes are the chemical transformations or conversions that are performed in a process.

examples: amination ,acylation,esterification,,oxidation,fermentation etc

Unit Operations: There are many types of chemical processes that make up the global chemical industry. However, each may be comprised of a series of physical treatment steps called unit operations. These are the steps, which are required to:

1. put the raw materials in a form in which they can be reacted chemically
2. put the product in a form which is suitable for the market.

It is the arrangement or sequencing of various unit operations coupled with unit processes and together with material inputs, which give each process its individual character. The individual operations have common techniques and are based on the same scientific principles. For example, in many processes, solids and liquids must be moved; heat or other forms of energy may be transferred from one substance to another; drying, size reduction, distillation and evaporation are performed.

examples: evaporation,crushing,size reduction,pumping,flotation etc