Question

what steps are involved in the manufacture of sulphuric acid by contact process

Answer 1

The contact process is the current method of producing sulfuric acid in the high concentrations needed for industrial processes. Platinum used to be the catalyst for this reaction; however, as it is susceptible to reacting with arsenic impurities in the sulfur feedstock, vanadium(V) oxide (V2O5) is now preferred.
The process can be divided into five stages:
Combining of sulfur and dioxygen (O2) to form sulfur dioxidePurifying the sulfur dioxide in a purification unitAdding an excess of dioxygen to sulfur dioxide in the presence of the catalyst vanadium pentoxide, under temperatures of 450 °C and pressure of 1-2 atmThe sulfur trioxide formed is added to sulfuric acid which gives rise to oleum (disulfuric acid)The oleum is then added to water to form sulfuric acid which is very concentrated