A Simple Note On Industrial Process Of Manufacture

The preparation of sulphuric acid creates sulphur dioxide, which is then converted to sulphur trioxide. The sulphur trioxide is later used to prepare sulphuric acid through contact. Sulphuric acid is primarily an oxidising agent, a powerful mineral acid, and a dehydrator. H2SO4 is the chemical formula for sulphuric acid. The acid is a clear liquid with no colour. It is miscible in water and, in particular, emits heat when it comes into contact with it.

Furthermore, the acid is corrosive. It will roast wood and much other organic stuff on interaction, but the odds of anything catching fire are nil. Inhalation of the acid might have negative health consequences. The rate of exposure and concentration determines it.

Industrial Process Of Manufacture Of Sulphur Compounds

Sulphuric acid comprises three elements: sulphur, oxygen, and hydrogen. As a result, the sources that are rich in such elemental components are appropriately selected for the task of producing Sulphuric Acid. Elemental sulphur or Sulphur Dioxide can be utilised as raw materials. Air and water are also incorporated.

Sulphuric acid is made by first producing sulphur dioxide, which is subsequently transformed into sulphur trioxide. Sulphur trioxide is then utilised in the contact process to produce sulphuric acid.

Sulphur may be found in mines, and Sulphur and Sulphur Dioxide are discovered in stack gases from the coal or oil sectors. Petroleum desulphurisation can produce sulphur or hydrogen sulphide. Sulphur dioxide is obtained by smelting metal silicide ores or isolating it from pyrite.

Here is the process in detail:

• Preparation of sulphur dioxide

The preparation of Sulphur dioxide gas is done by burning sulphur derived from any source. One must do this step with caution to ensure that the air provided for the combustion process is free from water or moisture. Any remaining water will cause acid to develop and corrosion to occur inside the combustion apparatus. In addition, if the sulphur comprises carbon-containing particles, it must be filtered. If the gas is not screened for pollutants, they may convey through the apparatus, and if they contact the catalysts, they will attempt to damage the purpose of the catalyst. Sulphur oxidation to sulphur dioxide is a completely irreversible process.

S(s) + O2 (g) → SO2(g)

• Preparation of sulphur trioxide

Vanadium Pentoxide (V2O5) is the catalyst utilised in the catalytic oxidation of sulphur dioxide to prepare sulphur trioxide. Before transferring the sulphur dioxide to the reactor, the gas is processed by Wet Scrubbing to eliminate any pollutants. The gas is processed via an electrostatic precipitator if any small particles are detectable. The process of converting sulphur dioxide to sulphur trioxide is bidirectional. The pressure is kept at 1.2-1.5 atm, and the temperature is kept at 410-430°C.

If the temperature goes over 430°C, the equilibrium is moved away from Sulphur Trioxide, so the operating temperature must stay within this limit. Catalytic reactors are often configured as four-stage bed reactors. As the gas is moved through one catalyst bed, its temperature goes up from 410-430°C to around 600°C. Therefore after each step, the gas must be cooled to the ideal temperature before proceeding to the next phase.

It is critical to keep sulphur dioxide from seeping into the atmosphere since it pollutes the air and is also a key contributor to acid rain. Dual absorption ensures that additional sulphur dioxide is turned into sulphur trioxide, which is helpful to the procedure regarding quality. After three steps, the purity is 97-98 per cent, and after four stages, it is almost 99 per cent.

2SO2(g) + O2(g) ⇌ 2SO3(g)

• Preparation of concentrated sulphuric acid

The generated sulphur trioxide is first allowed to react with strong sulphuric acid. Sulphur trioxide should not be diluted with water immediately because it causes fog to arise. The end product of this reaction is called oleum. The resulting oleum is later dissolved in water to produce concentrated sulphuric acid.

H2SO4 + SO3(g) → H2S2O7(l)

H2S2O7(l) + H2O(l) → 2H2SO4

The sulphur trioxide is hydrated by absorption in a packed tower filled with a specified range of Sulphuric Acid. This particular range is 98-99 per cent. If this concentration is too low, sulphur trioxide is not adequately absorbed and generates a bothersome mist. If the concentration is high enough, vapours become a significant factor within the tower. As a result, it is critical to maintain a high operation focus level. One may change the acid strength by adjusting the sulphur trioxide and water flow rates. The resultant acid strength can range between 91 and 100 per cent sulphuric acid.

Uses Of Sulphuric Acid

The acid is employed in the production of fertilisers, paints, dyes, medicines, fireworks, cleansers, and inorganic materials in concentrations ranging in the petrochemical industry and metallurgical operations. Sulfuric acid is used as the electrolyte in storage batteries, among its most well-known uses.

Conclusion

There are various ways of making sulphuric acid, each with a different level of effort, expense, and quality. The contact process is the most widespread of all of these. The contact process is among the most common processes for producing sulphuric acid. It is not only the most cost-effective method of producing sulphuric acid, but it also yields sulphur trioxide and oleum. A multi-step technique is used to manufacture sulphuric acid through the contact process. It includes the extraction of sulphur, followed by sulphur dioxide production. Sulphur dioxide is then converted to sulphur trioxide, the key component producing sulphuric acid.