1 Division of Combustion Physics, Lund University, Sweden.
2 Strategic Development, Vattenfall AB, Älvkarleby, Sweden.
Appl Spectrosc. 2018 Sep;72(9):1388-1395. doi: 10.1177/0003702818763819. Epub 2018 Mar 28.
Spectrally resolved ultraviolet (UV) absorption cross-sections of gas-phase sodium chloride (NaCl), potassium hydroxide (KOH), and sodium hydroxide (NaOH) were measured, for the first time, in hot flue gases at different temperatures. Homogenous gas-phase NaCl, KCl (potassium chloride), NaOH, and KOH at temperatures 1200 K, 1400 K, 1600 K, and 1850 K were prepared in the post-flame zone of laminar flames by seeding nebulized droplets out of aqueous solution of corresponding alkali species. The amount of droplets seeded into the flame was kept constant, so the relative concentration of different alkali species can be derived. The broadband UV absorption cross-section of KCl vapor reported by Leffler et al. was adopted to derive the absorption cross-section curves of NaCl, NaOH, and KOH with the corresponding measured spectrally resolved absorbance spectra. No significant changes in the spectral structures in the absorption cross-sections were found as the temperature varied between 1200 K and 1850 K, except for NaOH at around 320 nm. The difference between the absorption spectral curves of alkali chlorides and hydroxides is significant at wavelengths above 300 nm, which thus can be used to distinguish and obtain the concentrations of alkali chlorides and hydroxides in the broadband UV absorption measurements.
首次在不同温度的热烟道气中测量了气相氯化钠 (NaCl)、氢氧化钾 (KOH) 和氢氧化钠 (NaOH) 的光谱分辨紫外 (UV) 吸收截面。在层流火焰的后焰区，通过将相应碱物种的水溶液雾化成液滴来制备同质气相 NaCl、KCl（氯化钾）、NaOH 和 KOH，温度为 1200 K、1400 K、1600 K 和 1850 K。 播种到火焰中的液滴数量保持不变，因此可以得出不同碱物种的相对浓度。Leffler 等人报告的 KCl 蒸气的宽带 UV 吸收截面用于推导出 NaCl、NaOH 和 KOH 的吸收截面曲线，其相应的光谱分辨吸光度光谱。除了 320nm 左右的 NaOH 外，当温度在 1200 K 和 1850 K 之间变化时，吸收截面中没有发现光谱结构的明显变化。碱氯化物和氢氧化物的吸收光谱曲线在 300nm 以上的波长差异显著，因此可用于区分并获得宽带 UV 吸收测量中碱氯化物和氢氧化物的浓度。
