Ammonium Carbamate → Terephthalic Acid

Participants

Reaction Conditions

Reaction Steps

In a heated autoclave, provided with a mixer and filled partially with water, disintegrated poly/ethyleneterephtalate/ wastes in a form of scraps of film and bottles in the amount of 1000 g were placed together with a solution of 407 g of ammonium carbamate (NH4CONH2) in 10 liters of water. Then a content of the reactor was heated up to 200° C. and the temperature was kept till the digestion of poly/ethylene terephtalate/. The autoclave was relieved and the excess of carbon dioxide and water were removed. The water solution of products formed in the autoclave was filtered hot through a filter with active carbon. The chilled filtrate was acidified with sulphuric acid and the precipite of terephtalic acid was separated from a filtrate in a centrifuge. The resulted product was washed with distilled water, giving 862 g of terephtalic acid. From a solution, resulted after precipitation and separation ethylene glycol in amount of 321 g was separated, using distillation process, and the residue was ammonium sulphate.

Provenance & Evidence