烟碱提取新方法研究

调节低、次烟叶的含水率,使w(H2O)=12%～13%。在密闭容器中,控制温度540～550℃,使低、次烟叶碳化脱羧。产生的气体和液体用w(H2SO4)=70%的硫酸吸收,可得到w(C10H14N2)=4%左右的硫酸烟碱稀溶液。负压下,将该溶液浓缩至w(C10H14N2)≥20%、用80～100℃的饱和Na2CO3水溶液碱化至无气泡冒出为止,再加入稍过量的Na2SO4·10H2O,使水相形成饱和溶液,密闭、静置24h,即可把烟碱从水相中盐析出来。分出烟碱,在氮气保护下,负压进行两次蒸馏,收集140～148℃/4 0×103Pa馏分,可得w(C10H14N2)=98%以上的烟碱产品,产率在83%以上。提取过程中基本没有三废排放。

New Technology for Extracting Nicotine

Adopting carbonization-decarboxylation and sulfuric acid absorption technology,nicotine can be extracted from tobacco of inferior quality.The detailed process involves four steps.Firstly,it is necessary to regulate the water content in tobacco at 12%～13%,and then the tobacco is subjected to carbonization and decarboxylation in a closed system at 540～550 ℃.The gas and liquid produced are absorbed in sulfuric acid (70%) to form nicotine sulfate solution (4%).Secondly,the nicotine sulfate solution is concentrated to 20% under reduced pressure and neutralized with saturated sodium carbonate solution at 80～100 ℃.Thirdly,Na_2SO_4·10H_2O is added to salt out nicotine from the aqueous phase.Finally,nicotine is distilled under reduced pressure of 4.0×10~3 Pa and the fraction of 140～148 ℃ is collected.Yield of the product is 83% with purity of 98%.This new method realizes clean production without waste solid,liquid and gas.