Esterification is a direct esterification of acetic acid and ethanol in the presence of sulfuric acid. The production process can be continuous or batch.
Batch Process: Acetic acid, ethanol, and a small amount of sulfuric acid are added to a reactor and heated under reflux for 5-6 hours. Ethyl acetate is then distilled off and washed with 5% brine, neutralized to pH 8 with a mixed solution of sodium hydroxide and sodium chloride. It is then washed with calcium oxide solution and dried with anhydrous potassium carbonate. Finally, it is distilled, and the fraction collected at 76-77 °C is the product.
Continuous Process: Ethanol and acetic acid in a 1:1.15 (mass ratio) are continuously fed into the esterification tower. The esterification reaction is carried out at 105-110 °C under the catalysis of sulfuric acid. The generated ethyl acetate and water are distilled off from the top of the tower as an azeotrope. After condensation and separation, the upper ester layer is refluxed, the remainder is sent to the crude product tank, and the lower water layer is discarded after recovering ethyl acetate. The crude ester is then passed through a low-boiling-point removal tower to remove a small amount of water before entering a purification tower. The product is obtained at the top of the purification tower. This process is superior to the batch process.
The acetaldehyde process involves the production of ethyl acetate from acetaldehyde using aluminum ethoxide as a catalyst. Acetaldehyde, aluminum ethoxide, and other components are continuously added to two reactors connected in series, and the reaction is carried out at 0-20 °C. The conversion rate at the outlet of the second reactor can reach over 99.5%. Ethyl acetate is then obtained by distillation, with a yield of 95%-96%. This process is relatively economical.
