The usual breakdown of chemical industry is as followed:
It processes materials of big tonnage, in few stages of reaction, from raw materials easily accessible, in great capacity plants, requiring huge up-front capital investments.
This chemistry, which is also called heavy chemistry, is composed of two sub sectors:
- Inorganic Chemistry, which uses mostly water, air, salt, sulphur and phosphorus to produce sulphuric acid and its derivatives, products processed by electrolysis like chlorine or caustic soda, compressed gas and more elaborate products like fertilisers.
- Organic Chemistry, which concerns mostly the petrochemical and plastic production, synthetic rubber and the elastomers. The other "primary" outputs of organic chemistry are ethylene, benzene, propylene, butadiene, ethanol, acetone…
From the outputs of heavy chemistry, especially from the primary outputs and from vegetal and animal extracts, complex molecules are produced. They are the result of an intense research and development process. The outputs are processed from several chemical reactions in batches and in sequences.
The outputs are produced in smaller quantities than in the heavy chemistry and therefore can be very expensive, like the active principles of pharmaceuticals.
In this sector are produced outputs having specific characteristics, for specific uses : soaps and detergents, cosmetics, paints, varnishes and inks, cleaning products, glues and adhesives, pesticides, photography and film products, explosives…
These products are widely distributed in all industrial sectors and to the public.
It uses the active principles elaborated by the fine chemistry. They are formulated or mixed up to be assimilated by the body, and conditioned to be useful for the health of humans and animals.