Unit operations — the basic processes behind process industry
Regardless of whether it is a possible theft or an upset customer, the same basic rule applies: your safety weighs more than goods, a matter of principle or a specific case. Follow the shop's instructions, call for help in time, and remember that it is never your responsibility to solve a potentially dangerous situation alone.
The regulation on process operator training speaks of the apprentice's ability to perform tasks in production with physical, chemical and biological unit operations. It is a key concept: unit operations are the basic building blocks from which virtually all process plants are assembled — whether they make medicine, beer, ingredients or chemicals.
§Physical unit operations
- 01Filtering — separation of solids from a liquid or gas
- 02Sedimentation and separation — separation by means of gravity or centrifugal force
- 03Distillation — separation of substances by their boiling point
- 04Heat exchange — transfer of heat from one medium to another without them being mixed
- 05Drying — removal of liquid, typically water, from a product
- 06Grinding and mixing — changing particle size or composition of a mixture
§Chemical unit operations
Here the substances are transformed chemically — for example through neutralization, oxidation or synthesis, where new substances are created. This type of operation often places great demands on the control of temperature, pressure and residence time, because it is this that determines whether the reaction gives the desired yield and whether unwanted byproducts arise.
§Biological unit operations
Fermentation is the best-known example — the process behind beer, but also behind the production of enzymes and certain medicines like insulin. Here, not a chemical reaction is controlled, but a living system: yeast, bacteria or cells whose growth and production depends on temperature, oxygen supply, nutrients and pH value. Biological wastewater treatment also belongs to this category.
§How the operations are combined in practice
| Industry | Typical unit operations in sequence |
|---|---|
| Food ingredient | Filtering → drying → grinding/mixing |
| Medicine (synthetic) | Chemical synthesis → crystallization → filtration → drying |
| Brewery | Fermentation → filtering → pasteurizing (heat treatment) |
§Why it matters for you as an operator
Knowing the unit operations gives you a why behind the procedures and set points, not just a what. When you know that a step is heat exchange, you understand why the temperature on both sides of it matters, and you can better see through what a deviation on one side does to the other. That understanding is often what separates the one who can follow a procedure from the one who can also troubleshoot when something goes wrong.
“A system is not a black box — it is a chain of recognisable explainable steps.”