Chemical plant for vinyl acetate

Feed

Ethylene
Acetic acid
Air (O2 & CO2)

1) Evaporator

Vapourises acetic acid - rest already gases

2) Vapour phase reactor

Solid pellets of PdCl2 catalysts
Palladium supported on carrier metal e.g. silica/alumina to disperse the palladium
Reaction is exothermic so hay que manage heat to prevent catalyst deactivation

3) Liquid gas separator

• Cooling & condensation

• Phase separation -
  Liquids - VA, acetic acid, H2)
  Gas - unreacted ethylene, O2 CO2 other inert gases

• Recovery & recycling - separated gas washed with aa to recover any va, CO2 removed, ethylene recycled

4) Flash drum

Rapid pressure reduction
Ethylene & O2 rise (and are recycled to evaporator), CO2 falls

5) Flash drum

Pressure reduction to 1-2 bar
Vinyl acetate vaporises
Aa & H2O remain in liquid phase (Aa recycled to feed)

6) VA distillation column

VA moves up
Heavier impurities move down (AA, water)
Reflux improves separation efficiency