text: Ethene and oxygen are passed co-currently in a reaction tower at about 130 °C and 400 kPa. The catalyst is an aqueous solution of PdCl and CuCl. The acetaldehyde is purified by extractive distillation followed by fractional distillation. Extractive distillation with water removes the  lights ends having lower boiling points than acetaldehyde (chloromethane, chloroethane, and carbon dioxide) at the top,  while water and higher-boiling byproducts, such as acetic acid, crotonaldehyde or chlorinated acetaldehydes, are withdrawn together with acetaldehyde at the bottom.
  Due to the corrosive nature of catalyst, the reactor is lined with acid-proof ceramic material and the tubing is made of titanium.