The Maleic Anhydride plant was originally designed in 1979 to use Benzene as feed stock for Maleic Anhydride production. In June 2006, MA Plant was revamped to use N-butane as feed stock due to environmental and financial reasons. Declared capacity in the first year was 9,600 tonnes of crude MA.
Maleic Anhydride is produced by catalytic oxidation of N-butane in the reactor. Produced gases mixture contain MA in gas phase. In further steps, Gas mixture is cooled down to around 60°C to take out liquefied crude MA. Remaining MA in gas stream is washed in the scrubber column by forming Maleic Acid. Maleic acid is dehydrated to form crude Maleic anhydride. Total quantity of Crude MA is then distillated to remove residual impurities.
Produced liquid MA is stored at temperature above 60°C, or processed further on Pastillation section to produce solid MA.
Simplified flow diagram can be seen below: