Addressing The Potential of Alternative Configurations for CO2ER Supply Chains

Abstract

As global climate change concerns intensify, the search for renewable-based alternatives to products and processes that rely on fossil fuels becomes ever more important. A process that has been championed is the co-electrolysis of carbon dioxide and water, under the supply of renewable energy, via high-temperature solid oxide electrolyser systems. The technological combination can produce syngas directly. This syngas is a renewable-based alternative to fossil-based syngas, which has a widely established market and can directly be used for the generation of energy in power plants, or as a precursor for the production of carbon-based chemicals and fuels. Although many technology-specific improvements have been made in recent years that contributed to the creation of a promising outlook and an increasing number of demonstration projects, the feasibility and implications of implementing the process on an industrial scale remain largely unaddressed. Since many technologies fail in the transition from benchtop to industrial scale, a deeper understanding of the requirements that are opposed at an industrial scale should be obtained, to this end, this work applies an exploratory research approach to investigate the feasibility and opportunities of the supply chain that supports the production of syngas via co-electrolysis. To delineate the feasibility of the supply chain, this work considers two perspectives of feasibility; (i) the feasibility of the horizontal supply chain which encompasses the requirements and availability of feedstocks, technology and process scales, and market potential, and (ii) the feasibility of the vertical supply chain which encompasses the availability of materials required for the operation of solid oxide electrolyser systems. To investigate the opportunities of the supply chain, this work considers decentralised and centralised supply chain configurations. To initiate the research the individual supply chain units that are required for the process to be operatable at industrial scales were assessed. The requirements and scales of the individual units are matched with the current and expected future scales of technologies, feedstocks and markets. From this scale match, it can be concluded that based on feedstock availability and syngas market size, it is technically feasible to completely replace fossil-based syngas with renewable-based syngas produced by solid oxide electrolyser technology. However, several aspects such as the renewable energy requirements and the number of high-temperature solid oxide electrolyser systems that are required, impose practical limitations on the large-scale rollout. The influence of these practical limitations is aggravated after an assessment of the opportunities of decentralised and centralised supply chains, as both possibilities require capital investments on the scale of 1 Billion Euros and no positive return. A smaller implementation scale was also considered, and the limitations opposed to such a scale, seem much easier to overcome, highlighting potential future research directions. To delineate the feasibility from the vertical supply chain perspective, the material requirements of solid oxide electrolyser systems and the corresponding material availability were investigated. From this investigation, it can be concluded that from a global point of view, only Gadolinium opposes feasibility limitations. However, from a European point of view, the limitations seem much more severe. Based on the findings of this work, future research should focus on detailed analyses of the potential of solid oxide electrolyser supply chains at smaller scales, as there exist many opportunities that could improve overall supply chain performance, and smaller scales oppose less severe problems.