PETpla.net Insider 06 / 2018

MATERIALS / RECYCLING PET planet Insider Vol. 19 No. 06/18 www.petpla.net 22 Teijin Eco-Circle Process: Teijin is playing a pioneering role in Chemical Polyester Recycling (CPR). It builds on the experience of methanolysis of polyester waste, which has been operated by polyester manufacturers for many years. Together with Teijin’s existing equipment for the production of DMT and PTA, a robust process for the chemical recycling of polyester waste has been developed during the last 15 years. The initial production of PET resin for bottle making (B2B) was changed several years ago to the manufacture of all types of textile fibres and filaments, for profitability reasons. Teijin now works with more than 150 apparel and sportswear manufacturers worldwide to develop and manufacture products made from recyclable materials, as well as to collect and recycle these products at the end of their useful lives.Zhejiang Jiaren New Materials Co., Ltd. oper- ates a chemical recycling plant of 70t/d capacity on a Teijin license; a new 440t/d plant of is under construc- tion. Polygenta Re New process: “Polygenta’s proprietary, commer- cially proven technology Re New that produces polyester filament yarn from post-consumer waste PET bottles, is executed at 10,000t/a recycling facility in Nashik, India. The Re New process is a trailblazer technology given its abil- ity to recycle dirty clear and coloured PET bottles in a cost effective manner as well as significantly reducing the use of virgin petrochemical feed- stock and delivering superior quality products”. The basic principle of the Re New process is the washing of the PET bottle flakes with glycol; glycolysis of the flakes; fine filtration of the glyco- lysate; removal of the excess glycol; and polycondensation of the glycolysis product thus obtained. Simon West, the father of this process, started its development in the 1990’s; Polygenta completed the technical process devel- opment over three years, from 2010 to 2013. Today, POY filaments are produced by direct spinning from 100% recycled material. Aquafil Engineering: Aquafil’s process approach is similar to the Polygenta Re New process and based on mild glycolysis, purification of the glycolysate and direct repolyconden- sation by a polyester polycondensa- tion plant. Chinese approaches: Substantial industry development and R&D work towards of new PCR-technologies are underway in China. The major target is the development of recycling processes using polyester textiles as input material. Preferred processes are methanolysis and glycolysis, combined with the direct consumption of the recycled materials in polyes- ter production lines. The latest news about this processes will be presented during the next polyester recycling conference in China. 2.5 What to be done with the resulting non-PET-waste? Looking at a chemical PET recy- cling plant with an assumed capac- ity of 400t/d rPET and an input purity of 70%, 170t non-PET wastes are produced daily. This means that, as well as the chemical recycling plant, a waste treatment plant of this capac- ity will be required. In this context, the construction of a CHP (combined heat and power) waste incineration plant would be sensible, with the majority of the heat produced being used for the recycling plant. 3. Conclusion  In summary, it is becoming obvious that the main problem is not the lack of a chemical recycling process but the solution of logistical, capacitive and financial issues of a large-scale plant for PET recycling.  To simplify process chemistry and purification of the monomers, poly- mer destruction should refrain as much as possible from the use of catalysts, additives, solvents and process aids like KOH, NaOH, HCl or H 2 SO 4 and favour heat and pres- sure, along with process friendly chemicals like water, methanol or glycol. All that is added must be removed, up to a purity >99,99%!  There are several industry proven chemical recycling processes for licensing available in the market.  In view of the useful capacity of a recycling plant and its complexity, the cooperation of major polyester manufacturers, such as Idorama or Reliance, along with major consumers such as Coca-Cola, Nestlé, Danone, Lidl or P&G, will be essential for polyester to make a successful entry into the chemi- cal recycling www.polyester-technology.com