Towards the integration of remote renewable energy hubs with CCUS chain for a future energy system: the Belgian case

This article proposes a future multi-carrier energy system model for regions with high energy demand but limited renewable energy potential. These regions are struggling to reach their CO2 emission reduction targets. The system aims to combine the imports of low carbon resources as well as to set-up an efficient Carbon Capture, Utilization and Storage (CCUS) supply chain. Low carbon energy resources could be imported from Remote Renewable Energy Hubs (RREHs), which are regions with high renewable energy potential, but low local energy demand. The proposed multi-energy system is applied to the specific case of Belgium. It models legacy generation capacities, renewable energy potential, several carbon capture technologies, and the possibility to sequester or valorize the captured CO2 while serving three primary energy commodities: electricity, natural gas (methane - CH4) and hydrogen - H2. The Belgian system is interconnected with neighboring systems, RREHs and sequestration sites with the possibility of importing energy and exporting CO2. In the RREHs, two types of e-fuels can be produced and shipped back to Belgium: (i) green H2 using electrolysis and renewable energy and (ii) e-CH4 by combining green-H2 with CO2, either imported from Belgium or locally captured through Direct Air Capture (DAC) technologies. Post-combustion CO2 capture (PCCC) in Belgium is modeled using several capture configurations and two technologies. The first is monoethanolamine (MEA) absorption, and the second is a hybrid process combining vacuum pressure swing adsorption (VPSA) with a cryogenic carbon purification unit (CPU). Different characteristics of the CO2 emitters and technical requirements of CCUS technologies (pressure, liquefaction, transport, storage) are considered. Results show that, since the renewable energy potential is limited in Belgium, access to CO2 sequestration capacity is crucial for reaching the CO2 emissions reduction target. If the sequestration capacity is limited, energy imports from the RREHs become inevitable. This leads to higher energy costs in Belgium, resulting in a shift in the choice of PCCC technologies.