Saved Bookmarks
| 1. |
Describe the manufacture of H_2SO_4 by contact process |
|
Answer» Solution :Manufacture of SULPHURIC acid by contact process involves three steps: (i) Burning of sulphur in air to generate `SO_2`. (ii) Conversion of `SO_2` to `SO_3` by oxidation with air in the presence of `V_2O_5` as catalyst. (iii) Absorption of `SO_3` in `H_2SO_4` to obtain oleum `H_2S_2O_7`. A flow diagram for the manufacture of `H_2SO_4` is given below :  `SO_2` produced by burning of sulphur is freed from dust and other impurities. The plant is OPERATED at a PRESSURE of 2 bar and a temperature of 720 K. These are the optimum conditions for the conversion of `SO_2` to `SO_3`, according to Le Chatelier principle. `SO_3` produced in the catalytic converter is absorbed in concentrated `H_2SO_4` to produce oleum. Oleum is diluted with water to obtain `H_2SO_4` of DESIRED concentration. Sulphuric acid obtained as above is 96-98% pure. |
|