Environmental and Techno-Economic Feasibility of a BCCUS Project: the CO2SERRE Case Study in Centre-Val De Loire (France)

Abstract

The setting up of negative emissions appears more and more as a means to achieve the ambitious objectives of future GHG emissions reductions. Capturing, storing and/or valorizing CO2 issued from biomass is a promising way to obtain these negative emissions. With this objective, the CO2SERRE project studies the techno-economic and environmental feasibility of implementing an innovative 'BCCUS' pilot in France (Centre-Val de Loire). The concept consists in capturing CO2 from a biomass cogeneration plant in Orléans, valorizing it in local greenhouse farms, and storing the unused CO2 in geological reservoirs in the region. To feed the techno-economic and environmental feasibility assessment, each stage of the CCUS chain has been considered and assessed: capture, transport, geological storage, and use in greenhouses. The biomass facility emits around 80 kt of CO2 per year. A post-combustion capture by chemical absorption with monoethanolamine (MEA) is considered. The use of pipelines (with CO2 in supercritical phase) is considered for CO2 transport to the storage site, while the truck option is considered for transport of liquefied CO2 to the greenhouses. Based on the current practice of CO2 consumption in greenhouses and the needs of the producers of the region, the potential for captured CO2 use in greenhouse in the Orléans region has been estimated to 10 kt/year. Finally, geological and reservoir modelling showed that the targeted reservoir in the Paris basin formations would be able to store over 1 Mt/year, which is almost equivalent to the total annual emissions of the region Centre-Val de Loire. Life Cycle Analysis of the whole capture – transport – storage – utilization chain compared the system with CCUS to the actual situation. Different scenarios were considered according to the source of energy for capture process: steam from the biomass plant or from a gas-fired power plant; with or without energy valorization of the exhaust gases. The analysis showed that, globally, implementing CCUS in our case study avoids more environmental impacts than it generates. Avoided impacts are higher when the energy for capture comes from DBO, but it generates a gain loss for the operator. In addition, valorizing the exhaust gases energy is interesting especially when using energy from the gas-fired plant. Concerning use of the CO2 in greenhouses, the outcomes showed that the highest the share of utilization compared to storage, the lowest were the environmental impacts. Ongoing techno-economic analysis proved the avoided carbon price of carbon was already in line with price obtained on alternative BCCS process for the stored carbon, and with the price actually paid by the greenhouse farmers to their carbon supplier. Moreover, these avoided carbon prices could know further decreases in the future, thanks to a broader adoption of carbon use in greenhouse that can lead to larger scale and learning economies. However, a key challenge remains in the valuation of BCCS stored carbon, which are still not eligible to the EU-ETS (European Union Emissions Trading System).

Keywords: CCUS, BCCS, biomass energy, negative emissions, CO2 valorization, circular economy, techno-economic evaluation, LCA, environmental evaluation