June, 2005
Vol 1 Chapter 5: CO2 Removal from Power Plant Flue Gas - Cost Efficient Design and Integration Study
Gerald N. Choi, Robert Chu, Bruce Degen, Harvey Wen, Peter L. Richen and Daniel Chinn
Abstract: Nexant Inc., an affiliate of Bechtel Corporation, was given the task to evaluate various engineering options to reduce the costs of amine-based carbon dioxide (CO2) capture from flue gas generated by a 400 MW natural gas fired combined cycle (NGCC) power plant. ChevronTexaco, a member of the CO2 Capture Project (CCP), was the project manager for the study. The Nexant study consisted of three phases; Phase 1 involves technology survey and brainstorming to identify potential cost cutting ideas, and conducts tradeoff evaluations to quantify the potential cost reductions; Phase 2 consists of developing a base case CO2 amine plant design and cost estimate for benchmarking, and implements Phase 1 ideas to develop a low-cost amine plant design as a stand-alone plant; Phase 3 consists of developing a stand-alone NGCC power plant design and cost estimate for benchmarking, and an integrated NGCC/amine plant design to explore further cost savings via process integration. A total of 64 cost cutting ideas were identified during the Phase 1 study, of which 39 were considered unfeasible to evaluate in detail due to either insufficient performance or cost data. Tradeoff studies were performed on 18 of the remaining 25 ideas with eight being selected for final development of the Phase 2 low-cost amine plant design. The remaining seven ideas are related to the Phase 3 integrated NGCC/amine plant design, and two out of the seven were selected for implementation in the final integrated design. By incorporating the eight cost cutting ideas, a low-cost amine plant design was developed at a reduced capital cost of about 40%. All of the eight cost-reduction ideas implemented are related to equipment design changes, and are deemed to be technically feasible with current commercially available equipments. Their predicted performances (either via process simulation or from vendor quotes) will need to be verified via pilot plant testing. Phase 3 integration of NGCC with the low-cost amine plant further reduced the capital cost of CO2 removal by approximately 15% for a total cost reduction of about 55%. The integrated design incorporated ideas of reducing the gas turbine (GT) combustion air to half with flue gas recycle, and by relocating 75% of the amine reboiling duty directly into the HRSG (heat recovery steam generator) unit. These cost-reduction designs are considered technically possible. It is recommended that technology vendors to be funded for a preliminary engineering design to confirm the performance of low oxygen (~13% O2) combustion and the possibility of integrating an amine reboiler directly into a HRSG construction design.
Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1
Edited by: David C. Thomas, Senior Technical Advisor, Advanced Resources International Inc, USA
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