The synthesis of PET is carried out in two major steps:
- The first, considered to be the most critical, consists in the synthesis of PET oligomers from monomers of terephthalic acid and mono ethylene glycol.
- The second allows the synthesis of PET by polycondensation of the oligomers previously obtained.
By succeeding in this first step, Carbios demonstrates that it is now possible to use PET plastic waste rather than fossil resources for the synthesis of PET oligomers.
Carbios previously demonstrated that it had successfully depolymerized PET bottles into its initial monomers. A first scale up of the process has since been performed. After a proof of concept at the scale of one hundred milliliters, this depolymerization was carried out in reactors of 5 and 100 liters. At such last scale, 20 kilos of PET have been treated and depolymerized at 90%. Performances of the depolymerization process were perfectly identical regardless of the reactors volume, showing by then the strength of this technology. At the end of the depolymerization process, the terephthalic acid produced has been collected and purified. Its purity reaches a level above 99% and analytic technics of reference do not allow to make any difference with commercial terephthalic acid produced from oil.
“We have demonstrated that the purity of the terephthalic acid obtained through our original enzymatic process allows the efficient synthesis of PET oligomers. This is a new important step that reinforces the industrial potential of our technology. We are very confident in the forthcoming demonstration of a complete recycling of PET waste into new PET bottles of same quality as the original products. It is now our short-term goal before operating, with key players of the PET value chain, a pilot plant and launching the industrial demonstration of the process” comments Alain Marty, Chief Scientific Officer of Carbios.