炔醛法合成1,4-丁炔二醇中催化反应网络的分析与调控

Analysis and Regulation of Catalytic Reaction Network in 1,4‐Butynediol by Reppe Method

在含26根烛式过滤器的气、液、固三相反应器内,甲醛与乙炔会发生多种副反应,生成的副产物成分复杂且会导致过滤器堵塞,影响反应器长周期运行.通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)、电感耦合等离子体发射光谱仪(ICP)、凝胶渗透色谱仪(GPC)、热裂解-气相色谱-质谱联用仪(Py-GC-MS)和原位红外光谱仪(in-situ IR)等对炔醛法合成1,4-丁炔二醇生产反应器内堵塞物成分进行定性和定量分析,探究生成堵塞物的催化反应网络并通过实验验证影响该网络的显著因素.结果表明,反应器内堵塞物由无机物(w=39.4%)和有机物(w=60.6%)组成,无机物为破碎催化剂颗粒,有机物为乙炔和含氧中间体的共聚物.相较于新鲜催化剂,堵塞物中破碎催化剂在宏观形貌和微观组成上发生变化,其中的活性成分Cu^(2+)转化为Cu^(0),并伴随着其他成分的流失,Bi成分显著流失.聚乙炔由乙炔在Cu^(0)上发生自聚形成,含氧聚合物为甲醛与乙炔亲核加成反应生成的中间体.基于堵塞物的组成分析与Cu物种的演变,提出1,4-丁炔二醇生产反应器内可能的催化反应网络,同时,使用工业催化剂并结合体系pH值、乙炔的体积分数、甲醛的体积分数等条件进行验证.该催化反应网络对协同调控催化剂活化及其反应过程具有一定的指导意义.

Within a triphasic(gas-liquid-liquid)reactor equipped with 26 candle filters,various side reactions occur between formaldehyde and acetylene,resulting in complex by-products that can cause filter blockage and affect the long-term operation of the reactor.The composition of the blockage material in the 1,4-butynediol production reactor was qualitatively and quantitatively analyzed using techniques such as scanning electron microscopy(SEM),transmission electron microscopy(TEM),inductively coupled plasma optical emission spectrometry(ICP),gel permeation chromatography(GPC),pyrolysis-gas chromatography-mass spectrometry(Py-GC-MS),and in-situ infrared spectroscopy(in-situ IR).The catalytic reaction network responsible for the the formation of blockage was investigated,and significant factors influencing the network were experimentally verified.The results revealed that the blockage consisted of inorganic matter(w=39.4%)and organic matter(w=60.6%).The inorganic matter comprised catalyst fragments and the organic matter constituted copolymers derived from acetylene and oxygen-containing intermediates.Compared to fresh catalyst,the catalyst particles within the blockage undergone changes in both its macroscopic morphology and microscopic com-position.The active component Cu^(2+)transformed into Cu^(0),accompanied by the depletion of other constituents and notably a significant loss of Bi.Polyacetylene resulted from self-polymerization of acetylene on Cu^(0).The oxygen-containing polymers were intermediates formed from the nucleophilic addition reaction between formaldehyde and acetylene.Based on the analysis of the blockage composition and the evolution of Cu species,a possible catalytic reaction network within the 1,4-butynediol production reactor was proposed,and was verified by industrial catalysts in conjunction with parameters such as pH values,the volume fraction of acetylene,and the volume fraction of formaldehyde.The above reaction network offers guidance for the synergistic regulation of activation and reaction processes.