不同介质下松脂蒸馏中松香树脂酸的异构化反应

Isomerization of Resin Acid Under Desorption-distillation Processes with Different Medium

探讨了以H2O、N2和CO2等作为蒸馏介质,松脂蒸馏所得产品松香树脂酸发生异构化反应的变化规律。考察了蒸馏时出锅温度、介质类型和流量对树脂酸异构化反应的影响,结果表明:水蒸气作为蒸馏介质时枞酸型树脂酸的异构化反应较为激烈,而N2和CO2作为蒸馏介质时异构化反应较为温和,介质流量对异构化反应的影响不明显。采用气相色谱(GC)和气相色谱-质谱联用(GC-MS)分析了发生异构化反应的松香的树脂酸组成,并对产品松香的结晶趋势进行了检测观察,采用GC分析技术对低温阶段的结晶松香进行了树脂酸组成分析。结晶趋势检测显示低温阶段3种蒸馏介质都呈现出不同程度的结晶趋势,其中N2作为蒸馏介质时,蒸馏温度较低,产品松香的结晶趋势最小;结晶机理探讨显示,枞酸和长叶松酸含量的高低及其比值决定了产品松香结晶趋势的大小。

The variation regularity of isomerization reaction of rosin resin acid was discussed after desorption-distillation dissolution of rosin liquid with H 2O,N 2,CO 2 as distillation medium. The effects of desorption-distillation temperature, kinds of medium and medium flow rates on the isomerization of resin acid were investigated. The results showed that the isomerization reaction of abietic resin acid was more intense when water vapor was used as desorption-distillation medium, while the isomerization reaction was mild when N 2 and CO 2 were used as desorption-distillation medium, and the effect of medium flow on isomerization reaction was not obvious. The resin acid composition of rosin was analyzed by gas chromatography（GC） and gas chromatography-mass spectrometry（GC-MS）.The crystal tendency of the product was observed. The resin acid composition of the crystalline rosin at the low temperature stage was analyzed by GC. The results of crystallization tendency showed that the three kinds of desorption-distillation medium showed different degrees of crystallization tendency at the low temperature stage, the desorption-distillation temperature of N 2 desorption-distillation medium was the lowest, and the crystallization tendency of the product rosin was the smallest; Crystallization mechanism showed that the abietic acid and palustric acid content level and its ratio determined the size of the product rosin crystallization tendency.