甲醇中微量钠离子测定方法研究

Study on the Determination of Trace Sodium Ion in Methanol

甲醇制烯烃(MTO)工艺中,甲醇作为主要原料供给,对甲醇中碱金属有一定要求,要求甲醇中碱金属含量不大于0.1mg/L,碱金属(主要是Na^+、K^+)容易造成催化剂永久失活。通过对神木化学工业有限公司产品甲醇中钠离子测定方法进行总结,指出当需要准确测定甲醇中微量钠离子时,采用加热蒸干,除去有机质后测量,用二阶微分火焰发射光谱仪法和钠离子选择电极法测定,各有优缺点,用二阶微分火焰发射光谱仪法可准确测定钠离子含量在50μg/L以下的甲醇样品,用钠离子选择电极法可测定含量略高的钠离子的测定,可根据生产及用户需要进行测量。

In the MTO process,methanol is used as the main raw material.The process has certain requirements for the alkali metal in methanol.The alkali metal content in methanol is not more than 0.1 mg/l,and the alkali metal(mainly Na^+,K%)is easy to cause the catalyst permanent deactivation.This paper summarizes the determination method of sodium ion in methanol produced by Shenmu Chemical Industry Co.,Ltd.and points out that when When it is necessary to accurately determine the trace sodium ion in methanol,it shall be heated and evaporated to dryness to remove the organic matter,and then measured by the second-order differential flame emission spectrometer and the sodium ion selective electrode method.Each method has its own advantages and disadvantages.The secondorder differential flame emission spectrometer method can accurately determine the methanol sample with the sodium ion content below 50 ug/L,and the sodium ion selective electrode method can determine the sodium ion with slightly higher content It can be measured according to the needs of production and users.