摘要
以应用于烯烃催化裂解工艺中的具有独特择形性和酸性的ZSM-5分子筛为研究对象,采用重力分析仪在275,288及300K下对碳四烃(以正丁烷和丁烯-1为代表)在不同硅/铝比ZSM-5分子筛内的吸附和扩散行为进行了研究.建立了正丁烷和丁烯-1在ZSM-5分子筛上的双朗格缪尔吸附模型.同时,运用Fick扩散模型关联得到了正丁烷及丁烯-1在ZSM-5分子筛内的扩散系数.结果表明,正丁烷及丁烯-1在ZSM-5分子筛内的扩散属于晶体扩散,二者的扩散系数在10-14m2/s数量级,正丁烷的扩散速率大于丁烯-1.正丁烷与丁烯-1在ZSM-5分子筛内的扩散速率均随温度的增加而增加,随着体系平衡压力的增加先增加后减小,而且二者的扩散系数随样品硅/铝比的增加而增加.研究结果为碳四烃催化裂解工艺提供了相关的基础工程数据.
Adsorption and diffusion behavior of C4 fractions （n-butane and butene-1） on special shape-selective and acidic ZSM-5 zeolite with different Si/Al ratios, which is used as catalyst in olefins catalytic cracking （OCC） technology, was investigated using an intelligent gravimetric analysis apparatus （IGA-003, HIDEN） at 275, 288 and 300 K. The double Langmuir model was applied to simulate the adsorption of n-butane and butene-1 on ZSM-5 zeolite samples. The diffusion coefficients of n-butane and butene-1 were correlated in terms of the Fick diffusion model. The results indicate that the diffusion of n-butane and butene-lon ZSM-5 zeolites are intracrystalline diffusion, and the diffusion coefficients are of the order of magnitude 10^-14 m^2/s. In addition, the diffusion coefficients of n-butane are larger than those of butene-1 on ZSM-5 zeolites at the same temperature and pressure. Moreover, the diffusion coefficients of n-butane and butene-1 on ZSM-5 zeolites all increase with temperature, and increase with pressure first and decrease at high pressure. In addition, the diffusion coefficients of n-butane all increase with the Si/Al ratio. The results are applicable in the C4 olefins catalytic cracking technology.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2007年第4期661-667,共7页
The Chinese Journal of Process Engineering
基金
国家自然科学基金重点资助项目(编号:20236010
20476004)
中石化基金资助项目(编号:X504023)
