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For a sustainable-energy system, the industrial carbon emission should be zero or close to it. The partial capture of CO2, i.e., capturing only a share of the CO2, is discussed as an option for initiating the transition toward the decarbonization of industry by reducing the CO2 mitigation cost at industrial sites. This work models two approaches to achieving partial capture based on amine absorption: (1) capturing 90% CO2 from a split stream of the flue gas or (2) capturing less CO2 (≪90%) from the total flue-gas flow. A techno-economic analysis is carried out that considers scale, CO2 concentration, and process configurations (absorber intercooling and rich solvent splitting) when comparing the cost of partial capture to full capture, i.e., capturing close to all CO2 from the entire gas. Besides lowering absolute costs, the study shows that partial capture from CO2-rich gases may also lower specific cost (€ per tonne of CO2 captured) compared to full capture, despite the economy of scale, during certain market conditions. Operating expenditures, especially the cost of steam, are found to be dominating cost factors for partial capture, even for capture down to 200 000 tonnes per year.

The present work is related to the upscaling of calcium manganite–based oxygen‐carrier materials, which have a perovskite structure, both with respect to the use of inexpensive raw materials, i.e., instead of pure chemicals, and the upscaling of production to multitonne batches. Results are presented from the two different stages of material development, i.e., raw material selection and upscaling. The evaluation involves both operation in chemical‐looping combustor units of 300 W and 10 kW, and material characterization. In the latter unit, the gas velocities in the riser and in the grid‐jet zone of the gas distributor come close to gas velocities of industrial‐scale units and, therefore, this unit is also used to assess particle lifetime. Results from the various chemical‐looping combustion units and oxygen‐carrier materials produced from various raw materials of both high and low purity show that very high degrees of fuel conversion can be reached while achieving very high oxygen‐carrier lifetimes. The composition of the oxygen‐carrier materials seems robust and flexible with respect to the precursors used in its manufacturing.

Two different oxygen-carrier materials with similar molar ratios of Mn:Fe:Al were tested in continuous chemical-looping combustion operation with different fuels, i.e., syngas (H2/CO), methane, and kerosene. One oxygen carrier was manufactured by spray drying, and the other one was a naturally occurring ore that was crushed. Experiments were conducted in a bench-scale, chemical-looping combustion reactor with continuous fuel addition and continuous circulation of oxygen-carrier particles. In fresh state, i.e., before fuel operation, both materials showed clear CLOU properties. In used state, i.e., after fuel operation, the CLOU properties of the manufactured oxygen carrier were slightly higher than before, whereas those of the natural material decreased significantly. Operation with fuel was conducted for a total of about 47 h between 850 and 950 °C, and clear differences in fuel conversion were observed. At similar oxygen-carrier-to-fuel ratios and temperatures, the manganese ore achieved a clearly higher methane conversion, whereas the manufactured material achieved a higher conversion of H2 and CO. Near-complete conversion of syngas, i.e., >99%, was reached with both materials tested. Particle circulation was indirectly measured and used to estimate solids conversion during continuous operation. The materials were characterized with ICP-SFMS, XRD, and SEM/EDX, and rate indices were calculated based on data obtained in TGA tests with different reactants. Thermodynamic equilibrium calculations were made and used to interpret results from oxygen release and TGA tests. Attrition indices and material porosity were determined for fresh and used samples of the materials used. The manganese ore exhibited a clearly lower structural integrity during redox operation compared to the manufactured material. However, the cost of producing an oxygen carrier from an ore is significantly lower than manufacturing an oxygen carrier by spray drying.

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