Optimisation of Carbon Capture and Utilisation Value Chains

This PhD thesis identifies, examines and characterises all parts of the carbon capture and utilisation (CCU) value chain to assess its potential to be used as a CO2 emission mitigation option and, by extension, support global warming mitigation efforts. It puts CCU value chains in the context of global warming mitigation by establishing the relationship between increasing CO2 emissions, global warming and the efforts of the European Union to reduce them. CCU value chains can be defined as the process of generating profit by capturing CO2 from CO2-emitting sources and transporting it to CO2 receivers for utilisation, within a process or the production of commercial products. The examination of CCU value chains starts by identifying the chain’s individual steps followed by a breakdown of the steps in four sections that make up the chain: utilisation, CO2 sources, CO2 capture and CO2 transportation. Each section is introduced by discussing its purpose, process and limitations within the chain, followed by a characterisation of the key elements and identifying and specifying factors that could be used in optimisation. Utilisation happens at CO2 receivers where CO2 is sold for profit and utilised in a process or for the production of commercial products; CO2 sources produce the CO2 emissions; CO2 capture technologies capture CO2 at the source and prepare it for transportation; and CO2 transportation is responsible for delivering CO2 at the receiver for utilisation. Numerous attempts have been made in the past aimed at optimising individual steps of the chain, and various attempts have been made to integrate approaches and achieve optimisation for more than one of the steps, but these have proved difficult because of their high complexity. This PhD thesis chose a different and simpler approach that requires fewer variables and provides a quick and reliable holistic solution to propose optimised regional CCU value chain schemes by integrating all steps of the CCU value chain. It was concluded that CCU value chains show high potential for CO2 emission mitigation if they are rigorously assessed, tailored and optimised for a specified region before application.

The novel contributions of the thesis are:
• Knowledge base of CO2 receivers and their characterization
• Knowledge base of CO2 sources and their characterization
• Framework for the matching of CO2 sources with CO2 capture technologies based on their compatibility
• Models for estimating CO2 capture cost
• Algorithm and business model for CCU value chain optimisation

The first four concepts have been integrated within an algorithm, the main novelty of the thesis, which optimizes the implementation of CCU value chains, and a business model that proposes realistic CCU schemes in a given region. The developed algorithm and business model can map the CO2 sources and receivers in a specified region and select the sets of optimal solutions based on the optimisation preference of the user for the development of CCU value chains by matching CO2 sources and receivers based on (i) the technological compatibility and maturity of technologies, (ii) CO2 capture costs, (iii) CO2 transportation costs, (iv) CO2 utilisation costs and (v) profit within a defined project lifetime. The algorithm and the business model have been validated using real life examples (industry level, regional level, and national level) and have been also implemented in an online platform for enabling symbiotic value chains for solid waste management (the development of which happened as part of the Interreg V-B “Balkan Mediterranean 2014-2020” SWAN project where we as part of the University of Huddersfield were invited as experts in industrial symbiosis field, but which was outside the scope of this thesis). The application and validation of the algorithm and business model in these areas demonstrate the strengths of the novel concepts and their potential to commercialise CCU value chains and contribute to global warming mitigation, and also to be used in areas other than CCU value chain optimisation.