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Title: Evaluation and Characterization of Membranes for HI/H2O/I2 Water Separation for the S-I Cycle

Abstract

In the Sulfur-Iodine (S-I) thermochemical cycle, iodine is added to the product of the Bunsen reaction to facilitate the separation of sulfuric acid (H2SO4) from hydriodic acid (HI). The amount of iodine can be as high as 83% of the overall mass load of the Bunsen product stream, which potentially introduces a large burden on the cycle’s efficiency. Removal of water from the HI and I2 mixture would substantially reduce the amount of required additional iodine. In this work, Nafion® membranes have been studied for their use as de-watering membranes. Specifically, two thicknesses of Nafion membranes have been found to be effective in this application. The thicker membrane, Nafion-117®, produces moderate fluxes of water with very high separation factors. On the other hand, the thinner membrane, Nafion-112®, yielded very large fluxes of water, however with smaller separation factors. All membranes were found to be durable and did not degrade in contact with the feed stream over periods of time up to three months.

Authors:
Publication Date:
Research Org.:
Idaho National Laboratory (INL)
Sponsoring Org.:
DOE - NE
OSTI Identifier:
911782
Report Number(s):
INL/EXT-05-00723
TRN: US200801%%229
DOE Contract Number:
DE-AC07-99ID-13727
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
08 - HYDROGEN; EFFICIENCY; EVALUATION; HYDRIODIC ACID; IODINE; MEMBRANES; MIXTURES; REMOVAL; SULFURIC ACID; WATER; iodine; separation; sulfur-iodine thermochemical cycle

Citation Formats

Frederick F. Stewart. Evaluation and Characterization of Membranes for HI/H2O/I2 Water Separation for the S-I Cycle. United States: N. p., 2005. Web. doi:10.2172/911782.
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Frederick F. Stewart. Evaluation and Characterization of Membranes for HI/H2O/I2 Water Separation for the S-I Cycle. United States. doi:10.2172/911782.
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Frederick F. Stewart. Thu . "Evaluation and Characterization of Membranes for HI/H2O/I2 Water Separation for the S-I Cycle". United States. doi:10.2172/911782. https://www.osti.gov/servlets/purl/911782.
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@article{osti_911782,
title = {Evaluation and Characterization of Membranes for HI/H2O/I2 Water Separation for the S-I Cycle},
author = {Frederick F. Stewart},
abstractNote = {In the Sulfur-Iodine (S-I) thermochemical cycle, iodine is added to the product of the Bunsen reaction to facilitate the separation of sulfuric acid (H2SO4) from hydriodic acid (HI). The amount of iodine can be as high as 83% of the overall mass load of the Bunsen product stream, which potentially introduces a large burden on the cycle’s efficiency. Removal of water from the HI and I2 mixture would substantially reduce the amount of required additional iodine. In this work, Nafion® membranes have been studied for their use as de-watering membranes. Specifically, two thicknesses of Nafion membranes have been found to be effective in this application. The thicker membrane, Nafion-117®, produces moderate fluxes of water with very high separation factors. On the other hand, the thinner membrane, Nafion-112®, yielded very large fluxes of water, however with smaller separation factors. All membranes were found to be durable and did not degrade in contact with the feed stream over periods of time up to three months.},
doi = {10.2172/911782},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Sep 01 00:00:00 EDT 2005},
month = {Thu Sep 01 00:00:00 EDT 2005}
}
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DOI:  10.2172/911782
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