包埋型SiO_2空心球对轻烃的吸附特性

Adsorption characteristic of embedded hollow SiO_2 spheres for light hydrocarbons

为了研究二氧化硅空心球对轻烃的吸附特性,将二氧化硅空心球置于微孔滤膜和耐油垫圈构成的固定化吸附床中,在相同实验条件下对五种轻烃(正戊烷、正己烷、正庚烷、正辛烷、正壬烷)的吸附性能进行固定床吸附实验,且将实验结果与吸附质的物性参数关联分析。结果表明:不同轻烃在二氧化硅空心球上的吸附容量及穿透时间均为:正壬烷>正辛烷>正庚烷>正己烷>正戊烷;同种轻烃在3种二氧化硅空心球(N_0、N和N_3)的吸附量及穿透时间均为:N_3>N_1>N_0。二氧化硅空心球对轻烃的饱和吸附量与吸附质的分子量、沸点、密度呈正线性关系,与饱和蒸汽压成反比关系;轻烃在3种二氧化硅空心球上的吸附能大小均为:正壬烷>正辛烷>正庚烷>正己烷>正戊烷。

To study the adsorption effect of silica hollow spheres on light hydrocarbons,the silica hollow spheres were placed in a fixed adsorption bed consisting of a microporous filter membrane and oil-resistant seal gaskets.The adsorption performance of the hollow SiO_2 spheres toward five light hydrocarbons（ n-pentane,n-hexane,nheptane,n-octane,n-nonane） was then investigated under a constant set of operational conditions. The correlation between the experimental results and the physical parameters of adsorbed substance were also analyzed. The results indicated that the adsorption capacity and penetration time for（ N_0,N_1,N_3） the silica hollow spheres toward the various light hydrocarbons obeys the following trend： n-nonane 〉n-octane 〉n-heptane〉 n-hexane 〉n-pentane. Furthermore,for a given light hydrocarbon,the adsorption capacity and penetration time for obeys the following trend： N_3〉 N_1〉 N_0. The absorption capacity of the hollow SiO_2 spheres increased with the molecular weight,boiling point,and density of the light hydrocarbons. The correlation between the absorption capacity of the hollow SiO_2 spheres and the above-mentioned parameters appears to be approximately linear; however,the vapor pressure and adsorption capacity are inversely related. The adsorption energy of these three hollow SiO_2 spheres for light hydrocarbons is ordered as follows： n-nonane 〉n-octane 〉n-heptane〉 n-hexane 〉n-pentane.