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Title: Lab-scale Development of a Hybrid Capture System with Advanced Membrane, Solvent system, and Process Integration

Technical Report ·
DOI:https://doi.org/10.2172/1484714· OSTI ID:1484714
ORCiD logo [1]; ORCiD logo [2];  [3];  [4]
  1. Liquid Ion Solutions; Carnegie Mellon Univ., Pittsburgh, PA (United States)
  2. Liquid Ion Solutions LLC, Pittsburgh, PA (United States)
  3. Carbon Capture Scientific, Pittsburgh, PA (United States)
  4. Pennsylvania State Univ., University Park, PA (United States)

The objective of the project is to achieve lab-scale demonstration of a transformational hybrid membrane/solvent system for the capture of CO2 from flue gas. A novel process integration scheme was proposed to overcome the low partial pressure of CO2 present in flue gas. This scheme takes advantage of the potential synergies inherent in the membrane and solvent capture systems. The proposed hybrid technology replaces the second-stage membrane with a solvent capture process. The combustion air is used as a sweeping gas in the solvent stripper. This overall configuration has the major advantages of requiring much less air and eliminating the problems associated with oxygen slip in the membrane-based systems. Even more importantly, because of the presence of the air sweep in the stripper, much lower temperatures are required for solvent regeneration, which enables heat integration to the point that no process steam is required. This project was to perform lab-scale demonstration of Liquid Ion Solutions (LIS) transformational hybrid membrane/solvent system for post-combustion CO2 capture while demonstrating significant progress toward achievement of the overall fossil energy performance goals of 90% CO2 capture rate with 95% CO2 purity at a cost of electricity 30% less than baseline capture approaches. This report is written chronologically based on budget periods. Each budget period discusses the work performed and its results. At the end of each budget period the milestone charts are provided to show the progress. This project was not able to meet its stated goals. The performances of the power plant equipped with the hybrid process and Baseline Case B12B were compared. The simulation results showed that the power plant equipped with hybrid CO2 capture process has an improved thermal efficiency of 33.4% compared to the Baseline Case B12B, which is 32.5%. However, the COE for the hybrid process is $146.3/MWh which is higher than the $142.8/MWh for Case B12B. If this process were to be applied as a retrofit, it may make sense to use this configuration as it does not require any change in an existing plant configuration and steam cycle. However, for a new powerplant the capital cost is higher than the Case B12B. On the membrane development side, we successfully showed that interfacially-controlled envelope (ICE) membranes work. The inclusion of surface modified nano-particles results in much higher gas diffusivities. The Gen-1 ICE membrane developed under this project showed exceptional improved permeability for CO2. However, we ran into major problems which were associated with the scalability and reproducibility of the poly(phosphozene) polymers. The issues with scale-up are and batch to batch variability is also discussed. At the end of this report we have provided our recommendations on materials development for better membrane materials and alluded to the use of much simpler chemistry while keeping the concept of ICE membrane intact. It is also clear that vacuum and compression equipment is costly. If a process which can eliminate the use of vacuum and compression equipment would significantly decrease the overall cost of capture. Some thoughts regarding such system is also provided in the outlook portion of this report.

Research Organization:
Liquid Ion Solutions LLC, Pittsburgh, PA (United States)
Sponsoring Organization:
USDOE Office of Fossil Energy (FE)
DOE Contract Number:
FE0026464
OSTI ID:
1484714
Report Number(s):
DOE-LIS-0001
Country of Publication:
United States
Language:
English