| 摘要 |
<p>A process for removing contaminants from polyethylene terephthalate ("PET") components by depolymerising PET including transesterifying material containing PET by reacting an alkanediol or alkanediols at a temperature below the boiling point of ethanediol with the material for a predetermined period of time to form a mixture containing embrittled PET; crushing the mixture and separating uncrushed material from the crushed material which contains PET; transesterifying the crushed PET by reacting an alkanediol or alkanediols at a temperature between at or about the boiling point of ethanediol and 240 degrees Celsius with the recovered PET for a predetermined period of time to form a solution containing soluble short chain PET polymers and/or bis (hydroxy ethyl) terephthalate ester ("BHT"); recovering short chain PET polymers and/or BHT and ethanediol; and hydrolysing the recovered short chain PET polymers and/or BHT at elevated pressure and temperature for a predetermined period of time to form an ethanediol solution and crystals of terephthalic acid.</p> |
