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.

National infrastructure provides essential services to a modern economy: energy, transport, digital communications, water supply, flood protection, and waste water / solid waste collection, treatment and disposal. The OECD estimates that globally US$53 trillion of infrastructure investment will be needed by 2030. The UK's National Infrastructure Plan set out over £460 billion of investment in the next decade, but is not yet known what effect that investment will have on the quality and reliability of national infrastructure services, the size of the economy, the resilience of society or its impacts upon the environment. Such a gap in knowledge exists because of the sheer complexity of infrastructure networks and their interactions with people and the environment. That means that there is too much guesswork, and too many untested assumptions in the planning, appraisal and design of infrastructure, from European energy networks to local drainage systems. Our vision is for infrastructure decisions to be guided by systems analysis. When this vision is realised, decision makers will have access to, and visualisation of, information that tells them how all infrastructure systems are performing. They will have models that help to pinpoint vulnerabilities and quantify the risks of failure. They will be able to perform 'what-if' analysis of proposed investments and explore the effects of future uncertainties, such as population growth, new technologies and climate change. The UK Infrastructure Transitions Research Consortium (ITRC) is a consortium of seven UK universities, led by the University of Oxford, which has developed unique capability in infrastructure systems analysis, modelling and decision making. Thanks to an EPSRC Programme Grant (2011-2015) the ITRC has developed and demonstrated the world's first family of national infrastructure system models (NISMOD) for analysis and long-term planning of interdependent infrastructure systems. The research is already being used by utility companies, engineering consultants, the Institution of Civil Engineers and many parts of the UK government, to analyse risks and inform billions of pounds worth of better infrastructure decisions. Infrastructure UK is now using NISMOD to analyse the National Infrastructure Plan. The aim of MISTRAL is to develop and demonstrate a highly integrated analytics capability to inform strategic infrastructure decision making across scales, from local to global. MISTRAL will thereby radically extend infrastructure systems analysis capability: - Downscale: from ITRC's pioneering representation of national networks to the UK's 25.7 million households and 5.2 million businesses, representing the infrastructure services they demand and the multi-scale networks through which these services are delivered. - Upscale: from the national perspective to incorporate global interconnections via telecommunications, transport and energy networks. - Across-scale: to other national settings outside the UK, where infrastructure needs are greatest and where systems analysis represents a huge business opportunity for UK engineering firms. These research challenges urgently need to be tackled because infrastructure systems are interconnected across scales and prolific technological innovation is now occurring that will exploit, or may threaten, that interconnectedness. MISTRAL will push the frontiers of system research in order to quantify these opportunities and risks, providing the evidence needed to plan, invest in and design modern, sustainable and resilient infrastructure services. Five years ago, proposing theory, methodology and network models that stretched from the household to the globe, and from the UK to different national contexts would not have been credible. Now the opportunity for multi-scale modelling is coming into sight, and ITRC, perhaps uniquely, has the capacity and ambition to take on that challenge in the MISTRAL programme.