Determination of Water Content of Nitrogen Containing Hydrogen Sulfide by Karl Fischer Coulometric Titration
Determination of Water Content of Nitrogen Containing Hydrogen Sulfide by Karl Fischer Coulometric Titration
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DOI：
10.2116/analsci.18p575
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发表时间：
2019-03
影响因子：
1.6
通讯作者：
X. Zhi;Haifeng Wang;Baijun Liu;Xiaoping Song;Zhanyuan Li;Jia Li
中科院分区：
文献类型：
--
作者：
X. Zhi;Haifeng Wang;Baijun Liu;Xiaoping Song;Zhanyuan Li;Jia Li
天然气含水量的测量对安全生产具有重要意义，但复杂的基体使测量结果不准确。天然气中含有硫化氢（H_2S），它与碘（I_2）反应，使卡尔费休库仑滴定法（KFCT）给出较高的结果。研究了KFCT法测定含氮硫化氢中水分的方法。冷镜湿度计提供了一个参考水含量校准KFCT。根据ISO 10101的反应机理，通过扣除H_2S消耗的I_2，减少了H_2S的干扰，但修正后的结果仍然偏高。提出了H_2S与I_2的化学计量比为1：2.5的可能反应机理。改进后的KFCT法含水量误差不超过（3 + 2%. x）mg/kg（x，含水量单位为mg/kg），具有天然气在线监测的潜力。
Measuring the water content in natural gas is important for safety; however, complex matrixes make the results inaccurate. Natural gas contains hydrogen sulfide (H_2S), which react with iodine (I_2), causing Karl Fischer coulometric titration (KFCT) to give higher results. The KFCT method for the determination of water content of nitrogen containing H_2S was investigated. A chilled mirror hygrometer offered a reference water content to calibrate the KFCT. The interfering of H_2S was reduced by subtracting I_2 consumed by H_2S according to the reaction mechanism of ISO 10101; however, the modified results remained higher. A possible reaction mechanism with a stoichiometry of H_2S to I_2 of 1:2.5 was proposed. The improved KFCT method had an error of water content no more than (3 + 2%· x ) mg/kg ( x , water content in mg/kg) and had the potential of online monitoring of natural gas.