Pilot Testing of Calcium Looping at TRL7 with CO₂ Capture Efficiencies toward 99.

Area of Science:

• Chemical Engineering
• Environmental Science
• Energy Technology

Background:

• Calcium looping (CFB-CaL) is a promising technology for post-combustion CO2 capture.
• Existing CFB-CaL systems offer advantages like retrofitting, energy efficiency, and cost-competitiveness.
• Industrial sectors with challenging decarbonization needs require advanced capture solutions.

Purpose of the Study:

• To demonstrate fuel flexibility in CFB-CaL using biomass in an oxy-fired calciner.
• To showcase the potential for extremely high CO2 capture efficiencies in the carbonator.
• To report results from recent experimental campaigns at the TRL7 CFB-CaL pilot plant.

Main Methods:

• Experimental campaigns were conducted at the La Pereda TRL7 CFB-CaL pilot plant.
• Flue gases (over 2000 N m3/h) were treated in the carbonator.
• Biomass pellets (up to 2 MWth) were used in the oxy-fired calciner.
• A novel two-temperature-zone strategy was implemented in the carbonator.

Main Results:

• Fuel flexibility was demonstrated using biomass in the oxy-fired CFB calciner.
• Extremely high CO2 capture efficiencies, exceeding 99% in some cases, were achieved.
• The two-zone carbonator strategy involved cooling the solids-lean top region below 550 °C.
• Sufficient active CaO flow to the cooler top region was ensured.

Conclusions:

• CFB-CaL technology, with biomass fuel flexibility and enhanced capture strategies, is suitable for difficult-to-decarbonize industries.
• The developed two-zone carbonator approach significantly boosts CO2 capture efficiency.
• The TRL7 pilot plant successfully validated these advancements in CO2 capture technology.