The ambition of the BackCap proyect is to develop a new process to capture CO₂ from amortized combustion power plants, retrofitted for back-up power provision in highly renewable electricity networks, while supplying CO₂ for use or storage. To address the escalation of CO2 capture cost in such low capacity factor system, BackCap uses in-duct Ca(OH)₂ injection for CO₂ capture during the brief power production periods. The resulting CaCO₃ will be stored and used as a steady source of CO₂ and CaO by oxy-fuel calcination. 

• To obtain carbonation reaction kinetics and CO₂ carrying capacities of Ca(OH)₂ sorbents under relevant reactor conditions during the CO₂ capture step.

• To obtain key operation data with respect to the loss of active sorbent material when cycling the sorbent between of Ca(OH)₂ and CaCO₃.

• To demonstrate viability of carbonator reactors adapted to Ca(OH)₂ sorbent properties (particle/pellet size, Ca(OH)₂/CaO ratio,  specific surface).

• TRL4-5 proof of concept of Ca(OH)₂ entrained bed carbonation reactor with high CO₂ capture efficiencies (>95%) in a pilot prototype.

• To test sorbent regeneration from carbonated particles of Ca(OH)₂, using oxy-fuel combustion.

• To design a viable process for CO₂ capture from amortized coal power plants operated in back-up mode by minimizing the cost of capture at very low capacity factors, allowed by the use of modest scale and well-integrated calcination and hydration operations.

• To evaluate cost and economic viability of a full system including all BackCap elements.

• To quantify impacts of the new technology in future electricity grids with 80-100% share of renewables, including a benchmarking against Power-to-Fuel-to-Power and other backup options.