The Chemical Industry
The chemical industry converts raw materials into useful products.
-Products includes chemicals for use as drugs, fertilizers, detergents, paints and dyes.
The industry makes bulk chemicals on a scale of thousands or even millions of tonne per year. Eg. ammonia,sulfuric acide,sodium hydroxide,chlorine and ethene.
On a smaller scale the industry makes fine chemicals such as drugs and pesticides.
The chemical industry is reinventing many of the processes it uses. The industry seeks to become greener by:
- turining to renewable sources
-devising new processes that convert high proportions of the atoms in the reactants into the product molecules.
- cutting down the use of hazardous chemicals
-making efficient use of energy
- reducing waste
- preventing pollution in the enviroment.
The work of chemical industry
The basic raw materials of the chemical industry are
- crude oil
- vegetable materials
- minereals such as metal ores, salt, limestone, and gypsum
First step in any processes, is to take the raw materials and convert them into chemicals or mixture of chemicals, that can be fed into the process. Crude oil, for example is a complex mixture of chemicals. An oil refinery distils the oil and then processes chemicals from the distilliation column to produce purified feedstocks for chemical synthesis.
At the centre of the plant there is a reactor, where reactants are converted into products. The feed stock may have to be heated or compressed before it is fed to the reactor. The reactor often contains a catalysts.
Genreally a mixture of chemicals leaves the reactor. The mixture includes the desired products. There are also be by-products and unchangedstarting materials. So the chemical plant has to include equiment to seperate the main products and by-products and to recycle unchanged reactants.
Chemical plants need energy - some of the chemical reactions occur at hight temperature, so energy is needed for heating.
Alot of electric power is needed for pumps to move reactants and products from one plant to another.
Sensors monitor the conditions at all key points in the plant. The data is fed to computers in the control centres where technical teams controls the plants.
Products from the chemical industry
Chemical industry produces 5 main types of products -
Some made in huge quantities, other chemicals have high value but made in smaller amounts.
Basic inorganics including fertilizers:- the industry makes large amounts of these chemicals. Chlorine,sodium hydroxide,sufuric acid, and fertilizers are all bulk chemicals.
Petro chemicals and polymers:-
Petrochemicals plants use hydrocarbons from crude oil to make a great variety of products, including polymers. The industry makes ethene, this is then used to make different products including polymers and solvents such as ethanol.