A benchmarking methodology for CO2 capture processesPresentation Transcript
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
Background and motivation
Systematic approach to benchmarking
Conclusions and further work
Benchmarking of processes
Practice of comparing the performance metrics of a process to others that are considered as industry standard.
Snapshot of performance of the process to understand where it is in relation to a particular standard process
Commonly used performance metrics in CO 2 capture processes:
CO 2 capture processes
All CO 2 capture processes require work
Directly by ancillary units such as compressors, pumps etc.
Indirectly by thermal energy requirements
This work leads to energy penalty of CO 2 capture associated with the process
Emphasis on: improving overall efficiency (or reducing energy penalty)
What overall process efficiency can be achieved?
Benchmarking of CO 2 capture processes Process A Process B Process C Process D Efficiency Future technnology development Scenario 1 Scenario 2
Efficiency tends to a maximum
Thermodynamic ideal efficiency
Process efficiencies Thermodynamic ” ideal” Technology limited Economics limited Efficiency Thermodynamic ” ideal” Technology limited Economics limited Efficiency penalty Max theoretical efficiency Min theoretical efficiency penalty
Minimum work targets
Target before design – key aspect of process synthesis methodologies like Pinch Technology
The methodology developed will
Provide ideal work targets (and thus efficiency penalties) for capture processes
Provide benchmark for comparison
Identify losses and provide recommendations where largest improvement potentials lie
It is worth noting that though the thermodynamic minimum will never be achieved, it provides a common and definite basis for comparison of different processes.
Aim: To evaluate minimum theoretical work requirement for CO 2 capture processes without defining specifics of the unit operations involved.
Only process inputs and outputs specified
No detail process flowsheets
Decompose overall process route into identifiable process steps/unit operations.
Calculate mass and energy balance for each step of the overall process.
Calculate the entropy or exergy balance for each unit operation.
Evaluate minimum energy requirement for the overall process.
Decomposing the overall process route
The methodology will be used to develop minimum work targets for each of the three capture routes
Gross power output from the plant is kept constant – 400 MW
Pure products from separation processes
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
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
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
Variation of overall process efficiency with capture rate
Developing a systematic methodology for benchmarking CO 2 capture routes utilizing minimum work targets
Provides ideal work targets (and thus efficiency penalties) for capture processes
Provides benchmark for comparison
Provide recommendations for where largest improvement potentials lie and hence guide further research
Extend the methodology by introducing technology limitations as irreversibilities
This publication has been produced with support from the BIGCCS Centre, performed under the Norwegian research program Centres for Environment-friendly Energy Research (FME) . The authors acknowledge the following industrial partners for their contributions: Aker Solutions, ConocoPhilips, Det Norske Veritas, Gassco, Hydro, Shell, Statkraft, Statoil, TOTAL, GDF SUEZ and the Research Council of Norway (193816/S60).