A Scalable Process for the Chemical Recycling of PET using Ionic Organocatalysts

使用离子有机催化剂化学回收 PET 的可扩展工艺

• 批准号: EP/V012797/1
• 负责人: Joseph Wood
• 金额: $ 119.95万
• 依托单位: University of Birmingham
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FV012797%2F1
• 关键词: Scalable; Process; Chemical; Recycling; PET

There is an urgent need to devise processes for recycling plastics, with an estimated total of 8300 million metric tonnes of plastics produced to date, of which less than 10% have been recycled overall. The end fate of polymers can include landfill, burning which contributes to CO2 production, global warming, and discarding into the environment, including rivers and oceans. Of the materials which are recycled, mechanical or thermal recycling techniques typically produce a lower grade of polymer which can be used in applications such as clothing, insulation, garden and road furniture for example, and also has inferior properties (e.g. colour and mechanical specification) and value compared with virgin polymers. PET is selected as the principal polymer for depolymerisation studies in this proposal, owing to it being widely used, with typical applications in clothing, bottles and packaging. The world demand for PET resin is ~23.5 million tonnes and production capacity ~30.3 million tonnes, whilst only 30 % (US) - 52 %(EU) is currently recycled. However used PET bottles are priced £222.50/tonne whilst virgin PET resin is priced £1084/tonne, making a strong economic case for chemical recycling to produce the virgin polymer, rather than mechanical or thermal recycling to a lower grade product. Chemical recycling of PET can be achieved via methods such as alcoholysis, aminolysis, ammonolysis and glycolysis, including via catalytic methods such as ionic organocatalysts. Some drawbacks of currently available recycling methods such as glycolysis involve the separation and eradication of contaminants such as catalyst residue and dyes from the product, difficulty of separating the project BHET from the reaction mixture in case it repolymerises during vacuum distillation and requirement for high purity PET feed to make high grade recycled products.This proposal aims to address these drawbacks by developing a scalable, continuous process for PET depolymerisation. In particular we aim to study the effect of polymer additives and food contaminants in real wastes upon the depolymerisation, to understand how the catalyst/process can be made resilient to these issues. Key considerations will be to fully understand reaction kinetics, enabling catalyst immobilisation to enable recycling of it and developing strategies for product recovery. The proposed technologies are expected to deliver potential benefits including reduced reliance on fossil derived virgin plastics, potential to increase the market for chemically recycled polymers, and deliver of a scalable process. We have engaged Project Partners from across the recycling, polymer production and academic sectors including Suez, Avantium, Dupont Teijin Films, Process Systems Enterprise and University of Liverpool. They will provide or advise on samples for depolymerisation, catalyst supports, provide technical consultation on the work plan and advise on routes to commercialisation and impact delivery as outlined in their letters of support.

迫切需要设计回收塑料的工艺，迄今为止，估计总共生产了83亿公吨塑料，其中只有不到10%被回收。聚合物的最终命运可能包括垃圾填埋、燃烧（导致二氧化碳产生）、全球变暖以及丢弃到包括河流和海洋在内的环境中。在被回收的材料中，机械或热回收技术通常产生较低等级的聚合物，其可用于例如服装、绝缘、花园和道路设施等应用，并且与原始聚合物相比还具有较差的性能（例如颜色和机械规格）和价值。在本提案中，PET被选为解聚研究的主要聚合物，因为它被广泛使用，通常应用于服装，瓶子和包装。全球PET树脂的需求量约为2350万吨，产能约为3030万吨，而目前只有30%（美国）-52%（欧盟）被回收利用。然而，使用过的PET瓶的价格为222.50英镑/吨，而原始PET树脂的价格为1084英镑/吨，这使得化学回收生产原始聚合物，而不是机械或热回收到较低等级的产品具有很强的经济性。PET的化学再循环可以通过诸如醇解、氨解、氨解和糖解的方法实现，包括通过诸如离子有机催化剂的催化方法。目前可用的再循环方法如糖酵解的一些缺点涉及从产物中分离和消除污染物如催化剂残留物和染料，在真空蒸馏期间再聚合的情况下难以从反应混合物中分离项目BHET，以及需要高纯度PET进料以制备高等级的再循环产物。PET解聚的连续工艺。特别地，我们的目标是研究真实的废物中的聚合物添加剂和食品污染物对解聚的影响，以了解如何使催化剂/工艺对这些问题具有弹性。关键的考虑因素将是充分理解反应动力学，使催化剂固定化，使其能够回收利用，并制定产品回收战略。预计拟议的技术将带来潜在的好处，包括减少对化石衍生原始塑料的依赖，增加化学回收聚合物市场的潜力，以及提供可扩展的工艺。我们已经与来自回收、聚合物生产和学术领域的项目合作伙伴合作，包括苏伊士、Avantium、杜邦帝人薄膜、Process Systems Enterprise和利物浦大学。他们将提供或建议解聚样品，催化剂载体，提供工作计划的技术咨询，并就其支持信中概述的商业化和影响交付的路线提供建议。