炔醛法1,4-丁二醇生产过程甲基1,4-丁二醇的生成机理与控制分析

Reducing Methyl 1,4-butanediol of Reppe Method from the Theoretical Point

1,4-丁二醇(BDO)是一种重要的有机化工原料,目前国内各生产厂家的主要合成方法是炔醛法(Reppe法)。然而在实际生产过程中常伴有较多副产物的生成,其中对产品质量影响最大的是甲基1,4-丁二醇。基于此,本文首先对1,4-丁二醇的整体反应机理进行了深入分析,然后通过对副产物的生成机理与工艺条件的分析,得出了副产物的产生主要是由于在酸性环境下,随着反应体系中甲醛的消耗,乙炔铜络合物易水合生成乙烯基醇和乙醛,从而促进了后续副反应的发生。另外,升高温度和压力也同样会促进副产物的生成。因此在实际生产中可通过控制pH值、适当降低温度及压力来减少甲基1,4-丁二醇的生成。

1,4-butanediol(BDO)is an important raw material for the production of a variety of chemicals.At present,Reppe method dominates the production of BDO.However,a variety of by-products exist in the main product using this method,of which the Methyl 1,4-butanediol has a significant effect on the product quality.Therefore,the mechanism of the whole reaction network including the main reaction and side reaction was constructed firstly.And then the reaction mechanism and condition of Methyl 1,4-butanediol formation was carefully analyzed,evidencing that it is acetaldehyde and vinyl alcohol arising from the hydration of acetylene in acidic solution that promote the side-reaction.Additionally,the side-reaction is more sensitive to temperature and pressure compared with the main reaction.Therefore,it’s suggested that the pH value of reaction should be controlled in the range of 5~6 and temperature and pressure should be reduced appropriately to reduce the formation of Methyl 1,4-butanediol.