The document presents a methodology for benchmarking CO2 capture processes using minimum work targets. It decomposes CO2 capture processes into identifiable steps and calculates the minimum energy requirement for each step and the overall process. This provides an efficiency target for comparing different CO2 capture routes. Applying the methodology to post-combustion, pre-combustion and oxy-combustion capture routes shows that pre-combustion capture has the lowest minimum work requirement and highest efficiency. The methodology provides a basis for comparing processes and identifying areas for efficiency improvements.

1. Benchmarking Methodology for CO 2 Capture Processes using Minimum Capture Work Targets Rahul Anantharaman , Kristin Jordal and David Berstad SINTEF Energy Research [email_address] Novi Sad, Serbia 06.07.2011

6. Process efficiencies Thermodynamic ” ideal” Technology limited Economics limited Efficiency Thermodynamic ” ideal” Technology limited Economics limited Efficiency penalty Max theoretical efficiency Min theoretical efficiency penalty

7. Systematic Approach

11. Decomposing the overall process route

13. Post-combustion capture CH 4 +2O 2 +7.5N 2 -> CO 2 +0.28H 2 O(g)+1.72H 2 O(l)+7.5N 2 T carnot : 3911 ° C 400 MW -3.8 MW -4.0 MW

14. Pre-combustion capture CH 4 +2H 2 O -> CO 2 +4H 2 T carnot : 344 ° C -53.5 MW H 2 +0.5O 2 +1.9N 2 -> 0.06H 2 O(g)+0.94H 2 O(l)+1.9N 2 T carnot : 1546 ° C -2.7 MW -3.5 MW 400MW

15. Oxy-combustion capture -5.9 MW CH 4 +2O 2 + -> CO 2 +0.28H 2 O(g)+1.72H 2 O(l) T carnot : 3911 ° C 400 MW -0.8 MW -3.9 MW

16. Results

17. Variation of overall process efficiency with capture rate