Theme A – Process Modelling & Sustainability Assessment
It is recognised that if we are to attain our objective of recycling CO2 to a conventional fuel-stock, then a complex chemical process, involving multiple stages of reaction and separations as well as thermal integration and optimisation will be required. The existence of this complex context hinders interpretation of the highly necessary research required on novel unit operations since it is never clear that an improvement in one part of the process will actually improve overall performance. In addition, the principal objective of the Programme is to enhance the sustainability of hydrocarbon use and this too must be demonstrated. Thus changes in unit operations must, for example, produce less carbon than is generated by alternatives, be potentially economic, socially beneficial and achieve a high level of public acceptability. These important features of the Programme’s research are covered by our first theme.
The objective of SP1 is to develop process flow sheets for CO2 utilisation processes which incorporate best available technologies augmented, where appropriate, by advances delivered through the projects within Themes B & C. In this way, techno-economic feasibility may be assessed. The process simulation software package, Aspen Plus is used to calculate and track all mass and energy flows across the whole system. The information thus generated is used for sustainability assessments in SP2 to identify the most sustainable CCU process options considered within the project. This is being achieved through the development of a decision-support framework and a tool for sustainability assessment (environmental, economic and social). Taking a life cycle approach, environmental sustainability is evaluated using life cycle assessment (LCA), the economic performance through life cycle costing (LCC) and the social impact by means of social sustainability indicators. Integrating these sustainability considerations together, we are using these techniques to examine in detail the “hot spots” in the processes which limit their sustainability and then encourage those working in Themes B & C to provide solutions for the inefficiencies identified.