使用不同催化剂转产过程中淤浆法HDPE脱气仓结块原因分析

在英力士淤浆环管工艺高密度聚乙烯(HDPE)装置上,由采用钛系催化剂生产PE100级管材专用HDPE转换成用铬系催化剂生产的过程中,使用钛系催化剂的停车期间以及使用铬系催化剂的开车期间,粉料输送至低压闪蒸脱气仓都会产生块状的聚乙烯,严重影响装置的正常运行;通过对块状聚乙烯进行密度与凝胶渗透色谱分析,发现结块的聚乙烯主要为低相对分子质量、低密度的聚乙烯粉料黏结物。停车期间,将第一反应器氢气进料量降低50%,提前终止1-己烯进料,从而完全消除结块的形成。

Cause analysis on agglomeration in degasser in HDPE slurry process during catalyst replacement

The normal operation of the plant was affected by the agglomeration occurred in the degasser during the shutdown and start-up of Innovene slurry loop high density polyethylene(HDPE)plant replacing titanium catalyst by chromium catalysts.The agglomerated products were analyzed in terms of density and gel permeation chromatography.It is found that the agglomeration is composed of low molecular weight and low density polyethylene.The agglomeration is eliminated by decreasing the feeding of hydrogen by 50%and stopping the feeding of 1-hexene in advance in the first reactor during the plant shutdown.