Introduction
BoReTech has launched a new recycling process on the basis of chemical recycling technology, using chemically recycled BHET(rBHET) oligomers for PET bottle-to-bottle production. The rBHET oligomers generated from this process can be a substitute for part of polyester raw materials to produce recycled PET pellets, which may become a mainstream practice in the next stage for PET recyclers.
The application of rBHET oligomers to PET bottle-to-bottle production
According to a study conducted by PET Recycling Team GmbH (PRT), a member of Alpla Group, recycled PET made by the team produces 79% less CO2 emissions than virgin PET.
China is the world's largest country to produce rPET. Currently, due to regulatory and technical limitations, rPET beverage bottles in China are still blank in terms of food-grade application despite the whole country’s high PET recycling rate. So far, the use of rPET in packaging has been limited to the field of non-food-grade applications. However, the majority of rPET flakes, more than 80% of them, are being used in the production of textiles and fibers. Many companies in China are promoting the food-grade application of rPET, but there are still gaps in relevant domestic laws and regulations as well as standards for use, recycling, and evaluation. Nowadays, the food-grade application technology of rPET has been already mature, with all the relevant parties paying close attention to its application.
There are two main recycling types of PET: mechanical recycling and chemical recycling. The mechanical recycling for PET bottle-to-bottle production is the process of recycling end-of-life PET materials into new PET containers by mechanical processes such as washing, crushing, pelletizing, and SSP. The process of mechanical recycling is now mature and plays a significant role in PET recycling, which is crucial for sustainable development and environmental protection. However, some experts point out that PET mechanical recycling cannot achieve infinite times of recycling for PET, and the performance of PET will be affected after certain times of mechanical recycling.
The PET chemical recycling process, namely chemical depolymerization, has been increasingly popular in the last two years. Chemical depolymerization is the process of depolymerizing end-of-life PET materials into monomers through chemical agents. There are already projects based on chemical depolymerization all around the world with different treatment processes, including glycolysis, alcoholysis, and hydrolysis. Concern over how many times PET can be recycled without affecting its performance can be addressed due to the unique process when chemical recycling is applied to PET bottle-to-bottle recycling. However, chemical recycling requires a large feedstock in volume and has higher investment thresholds and complex process technology requirements.
Therefore, BoReTech has launched a new recycling process on the basis of chemical recycling, using the chemically recycled BHET(rBHET) oligomers for PET bottle-to-bottle production, combined with its more than 30 years of experience in PET recycling processes and bottle-to-bottle engineering integration capabilities.
Post-consumer PET bottles are washed and crushed into PET flakes, which are then chemically made into rBHET oligomers. The rBHET oligomers generated from this process can be a substitute for part of polyester raw materials. A certain proportion of rBHET oligomer powder is then mixed with PTA and MEG in the virgin PET production unit, where mixing starts from the molecular level and then goes through esterification, polymerization, and SSP to obtain rPET pellets. The co-use of rBHET oligomers and bottle-grade polyester raw materials may become a mainstream practice in the next stage for PET recyclers.
Advantages of rBHET oligomers’ application in PET bottle-to-bottle production
♻ The virgin PET production unit can be made use of, mixing rBHET oligomers powder with PTA to produce rPET bottle-grade pellets, the quality of which is higher than those produced by conventional mechanical recycling;
♻ Investment costs in equipment and production are 35% and 40%, respectively, lower than when mechanical recycling is used, and production can be scaled up more quickly;
♻ Material consumption is almost zero in the impurity removal process;
♻ The unique rapid EG washing and alcoholysis technology significantly reduces carbon emission;
♻ The finished product has reliable quality and high safety and does not require food-grade certification such as FDA;
