Abstract:

Acetylene dimerization catalyzed by Nieuwland catalyst for the production of monovinylacetylene (MVA) is the crucial step for the manufacture of chloroprene from acetylene. The influence of the additives, DL-alanine content, acetylene gas hourly space velocity and internal diameter of the gas distributor on the reaction process were investigated. In addition, a continuous two-stage dimerization reaction was carried out. The result showed that DL-alanine would induce lower acetylene conversion and higher MVA selectivity. Higher acetylene gas hourly space velocity would cause shorter apparent residence time and strong back-mixing, which led to lower acetylene conversion and MVA selectivity. Small internal diameter of gas distributor favored the enhancement of mass transference through gas-liquid interface and the attenuation of back-mixing, which induced both high acetylene conversion and high MVA selectivity. In a continuous two-stage reaction process, both acetylene conversion and MVA selectivity kept in a high level. When the gas hourly space velocity of acetylene was 100 h^-1, the acetylene conversion and MVA selectivity were 32.5% and 95.3%, respectively.

Key words: Nieuwland catalyst, acetylene dimerization, catalysis, monovinylacetylene, bubble column reactor, reaction engineering

摘要：

纽兰德催化剂催化乙炔二聚反应生产乙烯基乙炔是乙炔法生产氯丁二烯的关键步骤。考察了添加剂种类、DL-丙氨酸助剂添加量、乙炔空速和气体分布器孔径对乙炔二聚反应过程的影响,并进行了两级串联乙炔二聚反应试验。结果表明,添加DL-丙氨酸对乙炔二聚反应有抑制作用,但有利于提高乙烯基乙炔选择性。较大的乙炔空速会降低气体停留时间和增加返混现象,从而造成乙炔转化率和乙烯基乙炔选择性同时降低。缩小分布器孔径有利于降低气泡尺寸、增加气液传质面积和减少返混,可同时提高乙炔转化率和乙烯基乙炔选择性。当采用两级串联反应时,乙炔转化率大幅度提高,并且使乙烯基乙炔选择性保持较高水平。在乙炔空速100 h^-1的条件下,乙炔转化率为32.5%,乙烯基乙炔选择性为95.3%。

关键词: 纽兰德催化剂, 乙炔二聚反应, 催化, 乙烯基乙炔, 鼓泡反应器, 反应工程