Petrochemicals production has increased by 500% since 1980, and now accounts for nearly a third of industrial energy use and more than 10% of all oil and gas demand. There is clearly a need for large-scale change to reduce dependence on fossil fuels and reduce greenhouse gas emissions, but there are many possible configurations, relying on new and existing technologies. This project models those different scenarios, at global and regional level, to understand trade-offs between biomass demand, electricity requirements, and emissions. This requires an interdisciplinary approach, linking fundamental chemical engineering understanding of the processes themselves to the wider context.

As we move away from fossil carbon for our energy and non-energy needs, alternative carbon resources such as biomass, plastic waste, and captured CO₂ are expected to play an increasingly important role in the transition to a sustainable future. While these resources are often assumed to be more sustainable than fossil-based feedstocks, many systems-level questions remain unresolved.

For biomass, which feedstocks should be prioritised and where will they come from? Should land, water, and other resources be allocated to dedicated energy crops, or should greater emphasis be placed on residues and waste biomass? If so, are sufficient quantities available to support large-scale deployment? Furthermore, which biomass conversion technologies should be developed and deployed?

For plastic waste, how much recoverable material is actually available, and how much is lost throughout collection and waste management systems? Is it economically and environmentally viable to chemically recycle plastic waste streams that are currently landfilled or incinerated? Are the necessary business models, policies, and infrastructure in place to support a more circular plastics economy?

For captured CO₂, how much can realistically be diverted towards the production of chemicals and materials? What technologies, supply chains, and infrastructure would be required to fully realise the potential of carbon utilisation pathways?

More broadly, regardless of the carbon resource considered, what assessment frameworks and planning strategies are needed to avoid unintended environmental, economic, and societal consequences while replacing fossil-based feedstocks?

This project seeks to address these questions through a systems-thinking approach. It combines data analysis, resource assessment, supply chain analysis, and value chain modelling and optimisation to evaluate the availability, sustainability, and long-term role of alternative carbon resources in future industrial systems.

Life Cycle Assessment (LCA) is a general method for quantifying the environmental impacts of a chemical or process over its lifetime, including upstream production of feedstocks, energy, solvents, and so on; as well as impacts due to the use of the chemical; and then to dispose of or recycle the material at the end of its life. This allows hotspots to be identified to prioritise process improvements, and informs choices between lower-impact feedstocks or inputs. At Bath we pursue innovation in the methods themselves, such as to better quantify uncertainties and future scenarios, as well as applications to specific chemical technologies. An exciting aspect of this research is the ability to bring advances from how LCA is used in different fields, and apply it to chemical technologies. This is reflected by the diversity of the application areas in the example papers below, united by the common framework of understanding environmental impacts from processes and material flows.