石油化工
石油化工
석유화공
PETROCHEMICAL TECHNOLOGY
2009年
10期
1090-1094
,共5页
茂金属催化剂%乙烯聚合%聚乙烯%单颗粒传质模型%催化剂破裂
茂金屬催化劑%乙烯聚閤%聚乙烯%單顆粒傳質模型%催化劑破裂
무금속최화제%을희취합%취을희%단과립전질모형%최화제파렬
metallocene catalyst%ethylene polymerization%polyethylene%single particle mass transfer model%catalyst fragmentation
针对负载型茂金属催化剂催化乙烯聚合中的聚乙烯颗粒增长过程,采用改进的多粒模型建立了淤浆聚合条件下聚乙烯颗粒内部的单颗粒传质模型.采用该模型分析了负载型茂金属催化剂在聚合过程中的破碎行为,结合本征反应考察了传质对聚合反应的影响,计算出乙烯单体浓度和聚乙烯颗粒孔隙率在聚合过程中的变化.模拟结果表明,聚乙烯颗粒内部的传质阻力对聚合反应影响较大,聚合反应约200 s后,负载型茂金属催化剂由外至里逐层破裂.
針對負載型茂金屬催化劑催化乙烯聚閤中的聚乙烯顆粒增長過程,採用改進的多粒模型建立瞭淤漿聚閤條件下聚乙烯顆粒內部的單顆粒傳質模型.採用該模型分析瞭負載型茂金屬催化劑在聚閤過程中的破碎行為,結閤本徵反應攷察瞭傳質對聚閤反應的影響,計算齣乙烯單體濃度和聚乙烯顆粒孔隙率在聚閤過程中的變化.模擬結果錶明,聚乙烯顆粒內部的傳質阻力對聚閤反應影響較大,聚閤反應約200 s後,負載型茂金屬催化劑由外至裏逐層破裂.
침대부재형무금속최화제최화을희취합중적취을희과립증장과정,채용개진적다립모형건립료어장취합조건하취을희과립내부적단과립전질모형.채용해모형분석료부재형무금속최화제재취합과정중적파쇄행위,결합본정반응고찰료전질대취합반응적영향,계산출을희단체농도화취을희과립공극솔재취합과정중적변화.모의결과표명,취을희과립내부적전질조력대취합반응영향교대,취합반응약200 s후,부재형무금속최화제유외지리축층파렬.
Ethylene slurry polymerization on silica-supported metallocene catalyst was simulated based on a modified multigrain model. The modified model combined with the intrinsic reaction investigation was used to analyze catalyst fragmentation and polyethylene intraparticle mass transfer. The model can be used to calculate monomer concentration and growth of macro-particle during polymerization. The model can also be applied to predict the variations of particle porosity and monomer concentration distribution during the polymerization. Intraparticle mass transfer resistance has great effect on polymerization. The catalyst fragmentation happen shell-by-shell from surface to centre of catalyst at 200 s after starting of polymerization.
