OPTIMAL GRADE TRANSITION IN CONTINUOUS POLYMERIZATION PROCESS

WANG Jingdai; CHEN Jizhong; YANG Yongrong

您当前的位置：

首页 >

文章列表页 >

OPTIMAL GRADE TRANSITION IN CONTINUOUS POLYMERIZATION PROCESS

更新时间：2025-12-10

- OPTIMAL GRADE TRANSITION IN CONTINUOUS POLYMERIZATION PROCESS
- CIESC Journal Issue 4, (2001)
- 作者机构：
  
  浙江大学化学工程系
- 作者简介：
- 基金信息：
- DOI：
  CLC：
- Online First：25 April 2001，
  
  Published：25 April 2001
- 稿件说明：
移动端阅览
WANG Jingdai, CHEN Jizhong, YANG Yongrong. OPTIMAL GRADE TRANSITION IN CONTINUOUS POLYMERIZATION PROCESS[J]. CIESC Journal, 2001, (4).
DOI：

WANG Jingdai, CHEN Jizhong, YANG Yongrong. OPTIMAL GRADE TRANSITION IN CONTINUOUS POLYMERIZATION PROCESS[J]. CIESC Journal, 2001, (4). DOI：

摘要

以流化床乙烯气相聚合工艺为例建立了产品牌号切换模型

通过同时优化聚合温度、氢气和共聚单体的浓度、催化剂流率和料位高度等 5个操作变量的变化轨迹

使产品牌号的切换时间最短

过渡料数量最少 .研究表明

聚合温度、氢气和共聚单体的浓度对树脂性能指标的控制起主要作用 .为了减少过渡料的数量

一般均需降低催化剂流率和料位高度 .通过在目标函数中增加熔流比控制项可以抑制操作变量的剧烈调节

达到控制分子量分布的目的 .同时发现

产品牌号的正向和反向切换所得到的操作变量的最优轨迹很不相同

反映了系统的非线性

Abstract

A model of grade transition is presented for the commercial fluidized bed gas-phase polyethylene production process. For two polyethylene products

the model-based dynamic optimization is used to determine optimal grade changeover policies. The quantity of off-specification product and the time of grade transition can be minimized by optimization of manipulated variable profiles

such as polymerization temperature

the ratio of hydrogen to ethylene

the ratio of co-monomer to ethylene

catalyst feed rate

and bed level. The results show that polymerization temperature

hydrogen and co-monomer are sensitive to the quality of resin. It is always recommended that catalyst feed rate and bed level decrease in order to reduce the grade transition time and the quantity of off-specification product. It is demonstrated that melt index and density are not sufficient to characterize the properties of polymer produced during grade transition. A new performance index

i.e. ratio of melt flow ( MFR )

is included into the objective function

which could restrain the sharp fluctuation of operation variables and narrow the distribution of molecular weight of resin. There are much difference between the transition and reverse transition of grade which indicates the non-linearity of operation.

关键词

Keywords

references

Views

211

下载量

CSCD

Alert me when the article has been cited

提交

Tools

Publicity Resources

Zn-doped PdO/ZrO2 with rich oxygen vacancies for the synthesis of diphenyl carbonate from CO2 and phenol

Thermal analysis of phase change suspension jet impinging on wall surface covered with variable-shape porous layer

Study on the residence time distribution characteristics of the TPMS-Diamond static mixer

Methods of adaptive prediction and abnormal states traceability for sulphur content in flue gas desulfurization process

Identification of gas-liquid two-phase flow patterns in a riser based on recursive characteristics and CNN

Related Author

No data

Related Institution

No data

⁰