NANOCAP Achievements

MODELLING STUDIES

• An equilibrium-based model was developed for the optimization and evaluation of CO₂ capture processes operating on phase-change solvents. According to modelled results, the novel mixture N-Cyclohexylpropanamide (S₁N)/N-Dimethyl-Cyclohexylamine (DMCA) can achieve a high CO₂ to amine ratio for capture, equal to 1.35 (respective value for MEA is 0.51). Phase change solvents achieve a 42-45 % reduction in regeneration energy requirements, depending on flue gas characteristics, offering important improvements of operating expenditures
• A new rotating packed bed (RPB) model for the production of precipitated calcium carbonate (PCC) and hydromagnecite (BMC) was developed and validated. This model links the targeted outcomes of particle size distribution to important operating parameters and process KPIs, such as rotor speed and energy consumption. At the optimum operating range, an RPB would require 0.01-0.1 MW/ processed kg of slurry to produce particles of 9-10.2 nm size with a CO₂ capture efficiency 77.7- 94.6 %

EXPERIMENTAL STUDIES

• The novel phase change mixture S₁N/DMCA (3:1 mol ratio of amines) was tested in a pilot plant at CERTH in comparison to conventional solvent MEA. At a 3 mol total amine/L concentration a 2.29 - 2.50 GJ/tn CO₂ regeneration energy, depending on applied L/G ratio, was calculated, which is the lowest among phase change solvents reported in literature. This is an outcome of a 30 % reduced solvent flow towards regeneration, due to separation of phases, through which a CO2-rich phase is formed
• PCC and BMC nanoparticles were successfully produced through the slurry carbonation method at atmospheric pressure from calcium hydroxide and magnesia precursors, at various initial concentrations, rotating speeds, slurry and gas flow rates.
• The PCC nano-powders of high purity were produced, exhibiting good crystallinity, and comprising particles of 90 nm characteristic size and crystallite sizes of 36.8-47.3 nm. An original one-step approach for BMC nanoparticles synthesis was demonstrated in the RPB, verifying the findings of previous lab-scale experiments in conventional equipment. BMC nano-powder constituted of primary, sheet-like nanoparticles of 26-96 nm thickness, organized in secondary spherical particles of a few micrometers.
• In both cases, the particle synthesis took place at a simultaneously high CO₂ capture efficiency that exceeded 90 %, while characteristically compressed processing times were required until complete reaction of the precursor mass.

Technoeconomic studies

• In regard to the CO₂ capture unit operating on the novel phase-change solvent S₁N/DMCA, a techno-economic study predicted a capture cost of less than 30 € per ton captured CO₂, for both types of flue gas, which is a significant improvement compared to MEA (43 € per ton captured CO₂)
• In regard to the Rotating Packed Bed pilot-plant for carbonate nanoparticle production, the performed techno-economic study predicted overall production costs of 1000-2000 €/ton of PCC and 200-300 €/ton of BMC, depending on the facility’s capacity, initial concentration of slurry and filtration efficiency. The study also showed potential for further reductions of production cost, by processing more concentrated slurries

COMMERCIAL DEVELOPMENT – UPSCALING ACTIVITIES