摘要
采用离心喷雾干燥机合成公斤级球形黏土(海泡石、硅藻土和凹凸棒石)介孔复合材料。并对球形黏土介孔材料进行X射线衍射结构分析、比表面积-孔径分布和透射电镜测试,表明球形黏土介孔材料具有介孔结构和高度有序孔道。扫描电镜分析结果表明,3种新材料球体度均匀、分散性好。研究雾化器转速和反应物配比对球形黏土介孔复合材料粒形的影响,得到最佳喷雾干燥条件。考察海泡石、硅藻土和凹凸棒石球形黏土介孔复合材料负载聚乙烯催化剂的组成、结构和微观形貌。结果表明,3种黏土介孔复合材料在负载聚乙烯催化剂后仍然保持较好的微观形貌及其特有的介孔材料孔道结构。离心喷雾干燥制备球形介孔材料的实验优化条件:进、出口温度200℃和100℃,黏土介孔浆料浓度30%,雾化器转速12000 r·min^(-1)。以3种介孔复合材料作为载体负载聚乙烯催化剂进行高压乙烯聚合小试试验,结果表明,3种催化剂对乙烯聚合的活性(4000~4300)gPE·(gcat·h)^(-1)均优于当前工业用载体955硅胶负载同样茂金属后的乙烯聚合的活性1005 gPE·(gcat·h)^(-1)。聚乙烯粉料重要物性参数堆密度、熔融指数、平均粒径D50及碎粉率均优于工业用955硅胶得到的粉料物性。
Kilograms of spherical clay mesoporous composites(sepiolite,diatomite and attapulgite)were synthesized by centrifugal spray dryer.X-ray diffraction structure analysis,specific surface area-pore size distribution,and TEM testing were conducted to verify mesoporous structure and highly ordered pores in the composites.SEM analysis results show that these three new materials have uniform sphericity and good dispersibility.The influence of atomizer rotation speed and reactant ratio on the particle shape of spherical clay mesoporous composites was also studied,and the best spray drying conditions were obtained.The composition,structure,and microscopic morphology of clay mesoporous composite polyethylene catalysts were investigated in the article.The test results indicate that the three types of clay mesoporous composite materials still maintain good microstructure and unique mesoporous material pore structure after loading polyethylene catalyst.The optimum conditions for the composites were entrance/exit temperature of 200℃/100℃,content of clay slurry of 30%,and atomizer rotation speed of 12000 r·min^(-1).Three new materials were used as carriers to load polyethylene catalysts for high-pressure ethylene polymerization in small-scale experiments.The results showed that the activity of the three catalysts for ethylene polymerization[(4000-4300)gPE·(gcat·h)^(-1)]was better than that of the current industrial carrier 955 silica gel loaded with the same metallocene for ethylene polymerization[(1005 gPE·(gcat·h)^(-1))].The important physical properties of polyethylene powder,including bulk density,melt index,average particle size D50,and crushing rate,are superior to those obtained from industrial 955 silica gel.
作者
亢宇
Kang Yu(Beijing Institute of Chemical Engineering,China Petroleum and Chemical Corporation,Beijing 100013,China)
出处
《工业催化》
CAS
2024年第3期61-67,共7页
Industrial Catalysis
基金
中国石油化工股份有限公司北京化工研究院院控项目(G6001-12-ZS0225)。
关键词
催化剂工程
黏土介孔复合材料
乙烯聚合
离心喷雾干燥
catalyst engineering
clay mesoporous composite material
ethylene polymerization
centrifugal spray drying
