
Acetic Acid is evaporated and after adding catalyst is passed through a series of coils placed in a furnace. The Pyrolysis of acetic acid takes place in the coils placed in the furnace and products of phrolysis are ketene and water. The reaction can be represented by
CH3COOH Pyrolysis CH2CO + H2O
Catalyst
The exit gases from the furnace i.e. ketene, water, unconverted acid etc. are immediately cooled in a series of coolers to condense water and unconverted acid. The condensate from these coolers is sent to recovery section to recover acetic acid. The ketene gas is scrubbed with acetic acid in a series of scrubber towers to produce acetic anhydride. The reaction can be represented by the following equation:
CH3CO \
CH2CO + CH3COOH O
/
CH3CO
The over flow from the scrubbers i.e. Crude acetic anhydride subjected to fractional distillation to obtain pure acetic anhydride.
The Whole process is carried under reduced pressure.
MANUFACTURE OF ACETIC ANHYDRIDE
CONSUMPTION COEFFICIENTS BASIS 1000 KGS. ACETIC ANHYDRIDE
1. Acetic acid | 1285 Kgs |
2. Dry Saturated steam at 8 Kg/Cm2 | 5500 Kgs |
3. Electric power (Battery limit) | 180 KWH |
4. Cooling Water | 260 M3 |
5. Process Water | 0.5 m3 |
6. Referigeration at 4° C | 10TR |
7. Referigeration at – 10°C | 3TR |
8. Light Diesel Oil | 250 Ltrs. |
9. Tri Ethyl Phosphate | 2.5 Kgs |
10. Ammonia | 1 Kgs. |
11. Solvent | 25 Kgs. |
Applications for the manufacture of the following chemicals:
- Acetate Silk
- Cell Wool
- Plastic Materials
- Aspirin
- Pharmaceutical Chemicals
- Medicinal Chemicals