| abstract |
The invention relates to a method for the recovery of maleic anhydride by distillation from a solution of maleic anhydride in a high-boiling absorbent. The solution is obtained by the gas phase oxidation of a hydrocarbon and by at least the partial absorption of the oxidation products in the absorbent.For the method, i) the solution is introduced laterally into an inlet column with a reinforcing part above the inlet site and an output part below the inlet site; ii) an upper combining column communicating with the upper end of the reinforcing part and a lower combining column communicating withthe lower end of the output part are provided; iii) a take-off column, communicating with the upper combining column and the lower combining column, is provided; iv) maleic anhydride is drawn off asa side take-off from the take-off column, and compounds, boiling lower than maleic anhydride, are taken off at the head of the upper combining column, and the higher boiling absorbent is taken off inthe sump of the lower combining column. The maleic anhydride, obtained as a side take-off, has a low acrylic acid and acetic acid content. |