Search

For integrated operation of the sulfur-iodine (SI) hydrogen production process, a HIx solution consisting of HI, I2 and H2O could be recycled as a reactant to the Bunsen reaction section from the HI decomposition section. In this study, characteristics of the Bunsen reaction using the HIx solution in a co-current flow mode were investigated experimentally. In particular, we studied the effects of the operating variables (feed rates of reactants, H2O and I2 feed concentrations, temperature and volume of reaction zone) on the characteristics of the Bunsen reaction under steady-state conditions. Increasing the H2O feed concentration and decreasing the I2 feed concentration improved the extent of the Bunsen reaction. When increasing the temperature, the purity of the Bunsen products improved, but the SO2 conversion decreased. Characteristics of the Bunsen reaction were not affected by the variation in the volume of reaction zone. We concluded that SO2/HI/I2/H2O feed molar ratio controlled in the ranges of 1/1.8–2.0/3.9–4.1/14.8–15.6 was advantageous to achieve high SO2 conversion and improve separation performance of the Bunsen products at 333 K.

Traditional anti-reflective (AR) coating films prepared using tetraethylorthosilicate (TEOS) as a precursor absorbs water easily in addition to having a weak abrasion resistance. To improve the transmittance, hydrophobicity and abrasion resistance of AR coating film, various AR coating films were prepared using methyltrimethoxysilane (MTMS) as a precursor in addition to in- troducing a fluoroalkylsilane, acid catalyst, base catalyst and acid-base two step catalyst. The prepared AR coating films were then characterized by UV-Vis spectroscopy, contact angle analyzer, atomic force microscope (AFM), pencil scratch hardness test and cross-cut test. As a result, the transmittance of bare glass was 90.5%, while that of AR coating glass increased to 94.8% at curing temperature of 300 ℃. When the fluoroalkylsilane was added, the water contact angle of AR coating film increased from 96.3° to 108°, indicating that the hydrophobicity of the film was greatly improved. The abrasion resistance of AR coating film was also improved by the acid catalyst, whereas the transmittance increased by the base catalyst. In the case of AR coating film prepared using an acid-base two step catalyzed reaction, both the transmittance and abrasion resistance of the film was synergistically enhanced as compared with those of AR coating films prepared without introduction of a catalyst.