Pilot Testing of a Highly Efficient Pre-combustion Sorbent-based Carbon Capture System

Technical Report · Mon Dec 26 00:00:00 EST 2022

DOI:https://doi.org/10.2172/1906977· OSTI ID:1906977

Alptekin, Gökhan O. ^[1]

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1. TDA Research, Inc., Wheat Ridge, CO (United States)

TDA developed and demonstrated a highly efficient pre-combustion carbon capture system. The overall objective of this work was to develop a new sorbent-based pre-combustion carbon capture technology for Integrated Gasification Combined Cycle (IGCC) power plants. In this project our goal was to demonstrate the techno-economic viability of the new technology by 1) demonstrating it in large-scale slipstream tests, and 2) carrying out a high fidelity engineering and cost analysis. TDA’s process used an advanced physical adsorbent that selectively removes CO₂ from coal-derived synthesis gas above the dew point of the gas at temperatures as high as 300°C. The sorbent consists of a mesoporous carbon whose surface was grafted with functional groups that remove CO₂ via a well-known acid-base interaction. As documented in bench-scale experiments and field tests with actual coal gas, the sorbent achieved a very high capacity for CO₂ at temperatures as high as 300°C. The sorbent bound CO₂ more strongly than common physical adsorbents, providing the chemical potential needed for the high temperature operation. However, because CO₂ does not form a true covalent bond with the surface sites (as is the case with chemical absorbents), the sorbent regeneration could be carried out with only a very small energy input. The heat input to regenerate our sorbent was only 4.9 kcal per mol of CO₂, which is much lower than that for chemical absorbents (e.g., 29.9 kcal/mol CO₂ for sodium carbonate) and was similar to the requirements of physical solvents (e.g., 4 kcal/mol CO₂ for Selexol^TM). Because the sorbent operates above the dew point of the synthesis gas (unlike the Selexol^TM process), a higher power cycle efficiency can be achieved. With previous DOE/NETL funding (Contract No. DE-FE-0000469), we demonstrated the techno-economic viability of the technology in bench-scale tests and slipstream demonstrations at the National Carbon Capture Center (NCCC), Wilsonville, Alabama and Wabash River IGCC plant in Terra Haute, Indiana. We demonstrated a stable working CO₂ capacity for over 11,650 cycles with simulated synthesis gas. We also evaluated its performance with actual synthesis gas in two test campaigns at the Wabash River IGCC Plant, Terre Haute, IN and the National Carbon Capture Center (NCCC), Wilsonville, AL. The slipstream tests clearly showed that the actual coal gas constituents and potential contaminants (e.g. trace metals, halides, tars) had no effect on the sorbent’s ability to remove CO₂ (the same sorbent beds were used in both field tests with no sign of deactivation for 2,000 cycles with over 26,750 SCF of gas treated). As expected, due to the high temperature CO₂ removal capability and low energy needed to regenerate the sorbent, the power cycle efficiency with our process was greater than 34% on a higher heating value (HHV) basis; in comparison, the same IGCC plant equipped with the Selexol^TM solvent for carbon capture can only achieve 31.4% HHV efficiency. The capital cost for an IGCC system with TDA’s process is estimated as $2,417/kW_e, which is 12% lower than that of the IGCC/ Selexol^TM process. The levelized cost for electricity including the transport, storage and monitoring (TS&M) cost for CO₂ was calculated as $$\$$ $92.9/MWh (lowest reported to our knowledge), which is much better than the $105.2/MWh estimated for the IGCC/ Selexol^TM process. In this project (DE-FE0013105), TDA Research, in collaboration with our partners Gas Technology Institute (GTI), Illinois Clean Coal Institute (ICCI), University of California, Irvine (UCI), University of Alberta (UOA), Siemens, NCCC and Sinopec advanced the technical maturity of the technology; scaling it up by a factor of 100. We optimized the reactor design using computational fluid dynamics (CFD); using adsorption modeling we improved the pressure swing adsorption (PSA) cycle sequence. We carried out two field test campaigns with a fully-equipped 0.1 MW_e prototype unit (for a total of 844 hours) using actual synthesis gas to prove the viability of the new technology. A successful 30 day (707 hrs) evaluation was completed at NCCC under air blown gasification conditions. We demonstrated 97.3% carbon capture at 1,500 SLPM, 93% carbon capture at 1,800 SLPM, and 90% carbon capture at 2,100 SLPM in the NCCC tests. We also demonstrated the system for 137 hours at a Sinopec petrochemical plant under oxygen blown gasification, demonstrating 86% carbon capture at 2,660 SLPM. In collaboration with University of California, Irvine (UCI), we completed a techno-economic analysis (TEA) for TDA’s warm gas cleanup technology integrated to IGCC power plant. The net plant efficiencies (on a coal HHV basis) for the warm gas cleanup cases were estimated to be 34.0% for E-GasTM gasifier, 34.4% for GE gasifier, 33.4 for the Shell gasifier and 34.2 for the TRIG^TM gasifier (Cases 2, 4, 6 and 8 in this study) with a catalytic combustor for CO₂ purification, which are significantly higher than those for the Cold Gas Case, or an increase of as much as 12% in the heat rate for Case 2, 6% for Case 4, 9% for Case 6, and 9% for Case 8. The 1st year cost of electricity with the transport, storage and monitoring (TS&M) costs for the CO₂ included was $$\$$ $129.2/MWh for the E-GasTM gasifier Warm Gas Cleanup Case, $$\$$ $131.9/MWh for the GE gasifier Warm Gas Cleanup Case, $$\$$ $146.8/MWh for the Shell Gasifier Warm Gas Cleanup Case, and $$\$$ $129.9/MWh for the TRIG^TM gasifier Warm Gas Cleanup Case. For comparison, the costs for the baseline Cold Gas CO₂ removal with Selexol for the different gasifiers were: $$\$$ $146.6/MWh for the E-Gas^TM gasifier, $$\$$ $142.2/MWh for the GE gasifier, $$\$$ $159.0/MWh for the Shell gasifier and $$\$$ $144.3/MWh for the TRIG^TM gasifier. In summary, the costs for our system were 7 to 12% lower than the corresponding Cold Gas Cleanup cases. The results of this techno-economic analysis suggested that TDA’s high temperature PSA-based Warm Gas Clean-up Technology can make a substantial improvement in the IGCC plant thermal performance for achieving near zero CO₂ emissions for E-Gas^TM, GE, Shell and TRIG^TM gasifier based IGCC power plants. The capital expenses were estimated to be lower than that of Selexol’s™. Taken together, the higher net plant efficiency and lower capital and operating costs resulted in substantial reduction in the cost of carbon capture for the IGCC plant equipped with TDA’s high temperature PSA-based carbon capture system. Finally, in collaboration with Gas Technology Institute (GTI) we completed the environmental health and safety assessment for TDA’s warm gas carbon capture technology.

• Research Organization: TDA Research, Inc., Wheat Ridge, CO
• Sponsoring Organization: USDOE Office of Fossil Energy (FE)
• DOE Contract Number: FE0013105
• OSTI ID: 1906977
• Report Number(s): TDA-2942-TR
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
10 SYNTHETIC FUELS
20 FOSSIL-FUELED POWER PLANTS
carbon capture
IGCC power plants
CO2
synthesis gas