1. Biomass residue characterization and pre-treatment: Sustainable biomass residues suitable for oxy-combustion-based bio-CHP were identified and assessed across the Nordic, V4, and Iberian regions. Harmonised mapping and detailed characterization datasets were established for key residues, including pellets, olive pomace, forestry residues, and seaweed blends. Pre-treatment studies confirmed that pelletization and torrefaction improve feedstock versatility and energy density. Biomass reactivity under dry and wet oxy-combustion conditions was quantified, delivering validated kinetic sub-models for CFD.
2. Experimental advancements in oxy-combustion technologies: For oxy-MILD, upgraded lab-scale facilities enabled systematic biomass testing under air and oxy-fuel conditions, generating validated burnout and NOₓ datasets. For CLC, the 150 kW pilot was upgraded and operated with multiple biomass fuels, demonstrating stable operation, first CO2 capture performance data, and feasibility of low-pre-treatment feeding. For oxy-CFB, industrial-scale experimental data were analysed to support CFD validation.
3. Digital modeling and simulation tools: Validated CFD frameworks were established for oxy-MILD, CLC, and oxy-CFB combustion. Oxy-MILD models showed strong agreement with experiments, CLC reactive simulations were re-enabled following solver corrections, and an industrial-scale oxy-CFB base model firing biomass residues was validated.
4. Case studies for real-world implementation: Three regional showcase cases were fully defined, each including a baseline CHP system and a retrofit or new-build concept. Key technical and infrastructural data were collected, and initial process modelling was initiated to support techno-economic and environmental assessments in RP2.
5. Advancements in carbon capture and negative emission technologies (NET): Integrated flue gas cleaning and CO2 compression and purification concepts were developed for all oxy-combustion pathways. Process modelling showed that low-temperature CO2 distillation is required to meet transport purity specifications. Suitable commercial solutions for impurity removal were identified, supporting bio-CHP deployment as a NET.