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.