淤浆法聚乙烯装置反应釜中产物的特性

Properties of products in reactors of polyethylene plant by slurry method

在中国石油兰州石化公司17万t/a高密度聚乙烯装置上,采用三釜串联淤浆法生产工艺生产聚乙烯,利用扫描电子显微镜、凝胶色谱仪、差示扫描量热仪等表征方法,考察了3台反应釜中产物的粒径分布、相对分子质量分布、熔融-结晶性能等特性。结果表明:3台反应釜中产物的组分均呈不规则颗粒状,相对分子质量分布曲线均为单峰;第2、第3反应釜中的产物粒径分布趋于集中,相对分子质量分布较宽;第1、第2、第3反应釜中产物的熔融曲线和结晶曲线均只有1个峰,共聚单体的引入会降低共聚物的结晶能力。

Polyethylene was produced by slurry process(three reactors in series)in a 170 kt/a high density polyethylene plant in Lanzhou Petrochemical Company of PetroChina.The particle size distribution,relative molecular mass distribution and melt-crystallization properties of the products in three reactors were investigated by means of scanning electron microscope,gel chromatograph and differential scanning calorimeter,etc.The results showed that the components of the products in the three reactors were irregular particles,and the relative molecular mass distribution curves were all single peak.The particle size distribution of the products in the second and third reactors tended to be concentrated,and the relative molecular weight distribution was relatively wider.The melting curve and crystallization curve of the products in the first,second and third reactors had only one peak,and the introduction of copolymer would reduce the crystallization ability of copolymer.