摘要
采用浸渍法制备Cu-β/SBA-15复合分子筛,通过XRD、N2吸附-脱附、NH3-TPD、Py-FTIR等对其进行结构表征,结果表明:Cu-β/SBA-15具有微-介孔复合结构和表面弱酸性。以Cu-β/SBA-15为吸附剂,在间歇式微型反应釜中,进行静态吸附脱除二苯并噻吩(DBT)实验,考察了反应温度、反应时间和剂油质量比("剂"指吸附剂Cu-β/SBA-15,"油"指模拟柴油)对吸附量的影响,并对其吸附动力学进行了考察。结果表明,在反应温度120℃,反应时间120 min,m(剂)∶m(油)=1∶30的条件下,模拟柴油的脱硫率可达54.62%、吸附剂吸附硫容量为2.27 mg/g;在Cu-β/SBA-15对DBT吸附的初始阶段,准二级动力学方程和Elovich方程均能很好地反映吸附模式,而整个吸附过程中,准二级动力学相关系数R2>0.99,拟合计算出的平衡吸附硫容量qe=2.54 mg/g,与实际所测值相差很少,说明准二级动力学吸附模型能更全面的描述Cu-β/SBA-15对DBT的吸附过程,其吸附过程是液膜扩散和内扩散共同作用的结果。
The composite molecular sieve Cu-β/SBA-15 was prepared by impregnation method and characterized by means of XRD,N2adsorption-desorption,NH3-TPD,Py-FTIR. The results indicated that Cu-β/SBA-15 retained micro-mesoporous composite structures and had a good weak acidity.Subsequently,the static adsorption desulfurization experiments of β/SBA-15 in the dibenzothiophene/dodecane model oil at a bath micro-reactor were carried out. The factors affecting adsorption capacity,such as reaction temperature,reaction time,and mass ratio of adsorbent to model oil,were investigated.Moreover,the adsorption desulfurization kinetics was performed. The results showed that the desulfurization rate of simulated diesel oil and adsorption capacity of Cu-β/SBA-15 for sulfur reached54. 62% and 2. 27 mg/g at 120 ℃ for 120 min with a mass ratio of absorbent to model oil being 1∶30.The pseudo-second-order kinetics equation and Elovich equation could well reflect the initial stage of Cu-β/SBA-15 adsorption to dibenzothiophene. However, the entire absorption process of dibenzothiophene on Cu-β/SBA-15 followed a pseudo-second-order kinetics equation with a correlation coefficient greater than 0. 99,and the calculated equilibrium adsorption capacity qewas 2. 54 mg/g,which was close to the observed value,indicating that the pseudo-second-order kinetics equation could more comprehensively describe the adsorption process of Cu-β/SBA-15 for dibenzothiophene.Additionally,the adsorption process was controlled by both film diffusion and particle diffusion.
作者
杨静
沈健
石薇薇
YANG Jing SHEN Jian SHI Wei-wei(College of Petrochemical Engineering, Liaoning Shihua University, Fushun 113001, Liaoning, China)
出处
《精细化工》
EI
CAS
CSCD
北大核心
2017年第10期1153-1160,共8页
Fine Chemicals
