Theoretical study of liquid phase pyrolysis for efficient conversion of large-scale mixed plastic waste to hydrocarbon fuels through the sequence of b

Lead Research Organisation: Aston University
Department Name: College of Engineering and Physical Sci

Abstract

This research aims to link the concepts of fluid and solid turbulence, by developing a model based on a modified set of Navier-Stokes equations due to recent advances in internal length gradient theory in solids. There are links between the instabilities of flow within fluid and plastic dynamics, which lend themselves to the potential application of modified NS equations to solid flow. Sequentially the intention is to formulate a liquid-phase pyrolysis theory, which models efficient decomposition of plastic into hydrocarbon fuels.
The research will be of fundamental importance to the future of waste plastic processing and recycling; at present, plastic waste often does not biodegrade and lasts for years in landfill or breaking to nano-particles at sea. This research would offer an experimentally verifiable theoretical model for the efficient and safe recycling of waste plastic into usable fuel. There is potential for patent applications to be based on the results of this proposed project.
It is possible to consider plasticity as the turbulence of a solid and it is by this idea that we intend to link the hydrodynamics of the NS equations to the dynamics of "solid" plastics.
We will employ a sequence of bifurcations approach which, at present, has only ever been applied to fluid dynamics, alongside wave turbulence theory to develop a hybrid model which will be applicable to a wider class of differential systems, not only plastic decomposition.
The first stage of the project is to develop a system of PDEs for the two-phase process of decomposing plastic into fuel. This system will be based on modified NS equations. The recent advances of internal length gradient theory, allowing solids to be modelled as fluids, are key to this project as they provide insight into how turbulence within solids might be modelled.
Once formulated, the solutions of these equations, that will identify the different plastic states, will be approximated by a numerical software built on proprietary code. This stage of development will also allow for direct comparisons of the new coupled PDEs with experimental results for further validation and refinement of theory.
When the theory is sufficiently represented by the in-house software and the results produced are in-line with experimental data, optimisation of the software will produce fundamental results relevant to the large-scale recycling of plastic into fuel. Additionally, the software will be divided into single (for pedagogical reasons - e.g. undergraduate delivery) and multiple (for High Performance Applications) processor versions.
The initial stage of the project, to include a full research proposal, is expected to take 6-12 months. This phase will allow for careful planning of time and resources to minimise risk to the project and to ensure sensible deadlines are set. During this time and for a further 6 months, deeper reading into the literature will occur and initial work on the formulation of the coupled PDEs will begin.
Once the literature review is complete, for the rest of the 2nd and 3rd year, the pyrolysis equations will be formulated alongside initial development of the numerical software to verify the results. This will be an iterative process, as work on the theory will influence the software development and vice-versa. In the 4th year, once the numerical software is developed, further comparison of its results will be made with experimental data in order to identify processes for maximising efficiency of the conversion from waste to fuel. The 5th year of the research will constitute optimisation of the software in order to obtain better agreement with the verified theory. The final year will be devoted for the thesis write-up.

Publications

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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/T518128/1 01/10/2020 30/09/2025
2442111 Studentship EP/T518128/1 01/10/2020 30/09/2026 Thomas Harvey-Ball