CircuPlast - A Green Chemical Recycling Process for PET

该项目将开发一项先进的环保技术Circle Plast，通过将废旧的PET塑料(如锅、沙拉盘和浴缸)转化为可用于制造新鲜塑料的商品化合物来回收利用。目前，英国只有一半的PET废品被回收，其余的被垃圾填埋或焚烧。这是由于当今回收工艺的局限性：机械回收被广泛使用，但降低了PET的物理性能，限制了寿命和可用性；热解将PET转化为气体、焦油和其他物质的混合物，但不会产生PET生产所需的化学物质。我们的技术Circle Plast利用热压缩水(HCW)在高温高压下的独特强大特性，将PET废物转化为高价值的化合物，即对苯二甲酸(TPA)和乙二醇(EG)。这项技术将通过用可持续来源的替代品取代化石燃料衍生的原料，从而帮助防止塑料垃圾排放到环境中，同时减少与塑料制造相关的碳排放。该项目将展示CircuPlast在PET回收中的适用性，使用实验室规模的间歇反应器来优化工艺条件并产生实验数据，这些数据将被集成到该过程的计算机模型中，并用于设计工业规模的连续过程。扩大的工艺设计将包括聚酯原料的制备、HCW的水解转化和产品/副产品流的分离，以实现生产高纯度TPA和EG的高效、环保的路线。成功的结果将为将该技术推向中试规模的演示者提供一个宝贵的平台。除了帮助解决与环境中的塑料有关的详细记录的问题外，该项目还将寻求实现真正的循环经济方法来管理PET塑料包装，特别是因为目前的机械回收工艺仅限于无污染和未变质的PET废物。

This project will develop CircuPlast, an advanced eco-friendly technology, to recycle waste PET-based plastics (e.g., pots, salad trays, and tubs), by converting them to commodity compounds that can be used to manufacture fresh plastics.Currently, only half of the PET waste in the UK is recycled, with the remainder going to landfill or incineration. This is due to limitations in present-day recycling processes: mechanical recycling is widely utilised but degrades the physical properties of PET, limiting lifespan and useability; pyrolysis converts PET to a mixture of gases, tars and other substances but does not yield the chemicals desired for PET production.Our technology, CircuPlast, utilises the unique powerful properties of hot compressed water (HCW) at elevated pressures and temperatures to convert PET waste into high-value chemical compounds, namely terephthalic acid (TPA) and ethylene glycol (EG), which can then be used to manufacture fresh PET plastic.This technology will increase the overall recycling rate for PET and thereby help prevent the release of plastic waste into the environment whilst also reducing the carbon emissions associated with plastic manufacture -- by supplanting fossil fuel derived feedstocks with sustainably sourced alternatives.This project will demonstrate the applicability of CircuPlast to PET recycling, employing a laboratory-scale batch reactor to optimise process conditions and generate experimental data, which will be integrated into a computer model of the process and utilised to design an industrial scale continuous process. The scaled-up process design will include PET feedstock preparation, hydrolytic conversion by HCW, and separation of product/by-product streams to achieve an efficient, environmentally friendly route to high purity TPA and EG. Successful outcome will lend an invaluable platform to take the technology forward to a pilot scale demonstrator. As well as helping to address the well-documented issues relating to plastics in the environment, this project will also seek to enable a truly circular economy approach to the management of PET plastics packaging, especially as current mechanical recycling processes are limited to non-contaminated and non-deteriorated PET waste.