氰乙酸及副产氯化钠提纯工艺研究
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摘要
氰乙酸通常以氯乙酸为原料,经过中和、氰化、酯化反应,再经过二次脱水合成。过程产生大量的副产氯化钠,氯化钠晶体包裹氰乙酸导致产品收率减少,氯化钠固废中有机物含量大,后期处理成本较大。同时脱水后的氰乙酸仍然含有少量的水,对合成氰乙酸下游产品影响较大。为解决上述问题,进行了氯化钠震荡实验和氰乙酸提纯实验。结果表明,氰乙酸提纯实验中,选用无水甲醇作溶剂,m(氰乙酸)∶m(无水甲醇)=2∶1,旋转蒸发仪转速为200r/min,蒸馏时间为40min,氰乙酸纯度为98.8%;氯化钠震荡实验中,氯化钠质量分数为12.5%时,氰乙酸去除率为95.57%,提纯效果最佳。
This test group developed and produced cyanoacetic acid is based on chloroacetic acid,through neutralization,cyanide,esterification reaction and then after two times dehydration to form cyanoacetic acid.In this process,the following problems will occur,the synthesis of cyanoacetic acid will produce a large number of by-product sodium chloride,which will wrap cyanoacetic acid to reduce the output of products、product yield and purity.Furthermore,cyanoacetic acid still contains a small amount of water after dehydration,which brings difficulties in the later synthesis of cyanoacetic acid derivatives.In order to solve the above problems,the experimental team carried out the experiment of sodium chloride concussion and purification of cyanoacetic acid.The results showed that in the purification experiment of cyanoacetic acid,anhydrous methanol as the solvent,m(cyanoacetic acid)∶m(anhydrous methanol)=2∶1,the rotational speed of the rotary evaporator was 200 r/min,and the distillation time was 40 min,the purity of cyanoacetic acid was 98.8%.In the sodium chloride oscillation experiment.When the mass fraction of sodium chloride is 12.5%,the removal rate of cyanoacetic acid was 95.57%,the purification effect is the best.
This test group developed and produced cyanoacetic acid is based on chloroacetic acid,through neutralization,cyanide,esterification reaction and then after two times dehydration to form cyanoacetic acid.In this process,the following problems will occur,the synthesis of cyanoacetic acid will produce a large number of by-product sodium chloride,which will wrap cyanoacetic acid to reduce the output of products、product yield and purity.Furthermore,cyanoacetic acid still contains a small amount of water after dehydration,which brings difficulties in the later synthesis of cyanoacetic acid derivatives.In order to solve the above problems,the experimental team carried out the experiment of sodium chloride concussion and purification of cyanoacetic acid.The results showed that in the purification experiment of cyanoacetic acid,anhydrous methanol as the solvent,m(cyanoacetic acid)∶m(anhydrous methanol)=2∶1,the rotational speed of the rotary evaporator was 200 r/min,and the distillation time was 40 min,the purity of cyanoacetic acid was 98.8%.In the sodium chloride oscillation experiment.When the mass fraction of sodium chloride is 12.5%,the removal rate of cyanoacetic acid was 95.57%,the purification effect is the best.
引文
[1] 魏文德.有机化工原料大全[M].第2版.北京:化学工业出版社,1999.
[2] Pollakp,Lonza A G.Ullmanns encyclopedia of industrialchemistry[M].Weinheim:Wiley-VCH,1998.
[3] 邵洪福,赵明.氰基乙酸系列产品简介[J].山西化工,1996(1):47-50.
[4] 马建兵.氰乙酸的研究及应用[J].河北工业科技,2009,26(5):393-394.
[2] Pollakp,Lonza A G.Ullmanns encyclopedia of industrialchemistry[M].Weinheim:Wiley-VCH,1998.
[3] 邵洪福,赵明.氰基乙酸系列产品简介[J].山西化工,1996(1):47-50.
[4] 马建兵.氰乙酸的研究及应用[J].河北工业科技,2009,26(5):393-394.