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Title: Solvent Effects on the Photothermal Regeneration of CO 2 in Monoethanolamine Nanofluids

We present that a potential approach to reduce energy costs associated with carbon capture is to use external and renewable energy sources. The photothermal release of CO 2 from monoethanolamine mediated by nanoparticles is a unique solution to this problem. When combined with light-absorbing nanoparticles, vapor bubbles form inside the capture solution and release the CO 2 without heating the bulk solvent. The mechanism by which CO 2 is released remained unclear, and understanding this process would improve the efficiency of photothermal CO 2 release. Here we report the use of different cosolvents to improve or reduce the photothermal regeneration of CO 2 captured by monoethanolamine. We found that properties that reduce the residence time of the gas bubbles (viscosity, boiling point, and convection direction) can enhance the regeneration efficiencies. The reduction of bubble residence times minimizes the reabsorption of CO 2 back into the capture solvent where bulk temperatures remain lower than the localized area surrounding the nanoparticle. These properties shed light on the mechanism of release and indicated methods for improving the efficiency of the process. We used this knowledge to develop an improved photothermal CO 2 regeneration system in a continuously flowing setup. Finally, using techniques tomore » reduce residence time in the continuously flowing setup, such as alternative cosolvents and smaller fluid volumes, resulted in regeneration efficiency enhancements of over 200%.« less
Authors:
 [1] ;  [2] ;  [3]
  1. Univ. of California, Irvine, CA (United States). Dept. of Physics and Astronomy; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  2. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
  3. Univ. of California, Irvine, CA (United States). Department of Chemistry
Publication Date:
Report Number(s):
LLNL-JRNL-735611
Journal ID: ISSN 1944-8244; TRN: US1702016
Grant/Contract Number:
AC52-07NA27344
Type:
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 7; Journal Issue: 46; Journal ID: ISSN 1944-8244
Publisher:
American Chemical Society (ACS)
Research Org:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 14 SOLAR ENERGY; 20 FOSSIL-FUELED POWER PLANTS; carbon black; carbon capture; nanoparticles; photothermal; solar energy
OSTI Identifier:
1393339