Conceptual design of pre-treatment units for co-electrolysis of CO₂ and water

Abstract

Reaching our climate goals will require urgent advancements in the development of fossil-free technologies. Solid-oxide electrolysis (SOE) at high-temperature is a promising candidate for combining CO₂ utilization and renewable electricity use. Explorative techno-economic analyses are being performed to understand the full plant design requirements for integrated SOE systems. However, there is still a lack of understanding of the potential impact that the pre-treatment of CO₂ will have on the overall design and economics of a SOE-based system. To address this knowledge gap, as a first step, the process model of the pre-treatment units needed to purify CO₂ from a bioethanol plant is developed in Aspen Plus in the current work. Based on the preliminary results of this paper, the equipment costs mainly stem from the units related to the removal of sulfur (~65%) and alcohols (~32%). The energy costs are almost entirely related to the cryogenic distillation step required for the removal of non-condensable gases (~96%).