水溶性无机盐对三甘醇脱水性能影响的实验研究

Experimental study on the effect of water-soluble inorganic salts on the dehydration performance of triglycol

目的分析作为主要杂质之一的水溶性无机盐对三甘醇(TEG)脱水性能影响的原因,为三甘醇质量控制提供依据。方法通过分析废三甘醇水溶性无机盐的组分和质量分数,确定了NaCl、KCl、MgCl_(2)、CaCl_(2)、Na_(2)SO_(4)、NaHCO 3、FeCl_(3)、BaCl_(2)、NaF 9种水溶性无机盐作为杂质,分别在质量分数为15.5 mg/g、温度为182℃的条件下,循环再生50次和连续加热48 h,以模拟循环再生三甘醇和滞留在重沸器中三甘醇的再生过程,分析了再生三甘醇组分和性质变化。结果在多次循环再生的条件下,水溶性无机盐对三甘醇的组分和性质几乎没有影响,只是水含量有所增大。而在连续长时间加热再生的条件下,三甘醇有效含量下降,有机杂质增多。这些有机杂质并不适应三甘醇脱水系统的要求,造成再生后的三甘醇脱水性能和pH值下降、发泡性能增强。结论水溶性无机盐对三甘醇性质的影响主要取决于再生条件,循环再生不会影响三甘醇的性质。在再生温度下连续长时间加热,水溶性无机盐会使三甘醇性质发生明显变化,从而使三甘醇在脱水系统中的适应性下降。

Objective Analyze the reasons for the influence of water-soluble inorganic salts as one of the main impurities on the dehydration performance of triglycol(TEG),so as to provide a basis for the quality control of TEG.Methods By analyzing the composition and mass fraction of waste TEG water-soluble inorganic salts,nine water-soluble inorganic salts,such as NaCl,KCl,MgCl_(2),CaCl_(2),Na_(2)SO_(4),NaHCO_(3),FeCl_(3),BaCl_(2),and NaF,were determined as impurities.Under the conditions of mass fraction was 15.5 mg/g and the temperature was 182℃,by 50 times of cyclic regeneration and continuous heating for 48 hours,the regeneration process of cyclic regeneration of TEG and TEG retained in the reboiler was simulated,and the regeneration process of TEG was analyzed.Results The water-soluble inorganic salt had little effect on the composition and properties of TEG under the condition of multiple cycles of regeneration,but the water content increased.However,under the condition of continuous heating and regeneration for a long time,the effective content of TEG decreased and the organic impurities increased.These organic impurities didn’t meet the requirements of the TEG dehydration system,resulting in the decrease of the dehydration performance and pH value of the regenerated TEG,and the enhancement of the foaming performance.Conclusions The influence of water-soluble inorganic salts on the properties of TEG mainly depends on the regeneration conditions,the recycling and regeneration will not affect the properties of TEG.Continuous heating for a long time at the regeneration temperature,the water-soluble inorganic salts will change the properties of TEG significantly,resulting in the decline of TEG adaptability in the dehydration system.