Cu-β/SBA-15的吸附脱硫性能及吸附动力学

Adsorption desorption and adsorption kinetics of Cu-β/SBA-15

摘要:

（辽宁石油化工大学 石油化工学院，辽宁抚顺 113001） 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实验，考察了反应温度、反应时间和剂油质量比对吸附量的影响，并对其吸附动力学进行了研究。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%、吸附量为2.27 mg/g；在Cu-β/SBA-15对二苯并噻吩吸附初始阶段，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量qe=2.54 mg/g，与实际所测平衡吸附量2.27 mg/g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对二苯并噻吩的吸附过程，其吸附过程是液膜扩散和内扩散共同作用的结果。

Abstract:

The adsorbent of Cu-β/SBA-15 was synthesized by the impregnation method，and the samples were characterized by means of XRD，N2 adsorption-desorption，NH3-TPD，Py-FTIRThe results indicated that Cu-β/SBA-15 could retain the micro-mesoporous composite structure and has a good weak acidity.Using the β/SBA-15 as adsorbent，the static reaction of adsorption removal dibenzothiophene in a bath micro-reactor.The influences of reaction temperature、reaction time and reagent oil mass ratio to oil on adsorption capacity were investigated.Morever，experimental study of adsorption kinetics was performed.The results showed that the desulfurization rate of simulated diesel oil was 54.62% and the adsorption capacity was 2.27 mg/g at the reaction temperature of 120 ℃，reaction time of 120 min and reagent oil mass ratio of 1:30.In the initial stage of Cu-β/SBA-15 adsorption to dibenzothiophene，the pseudo-second-order kinetics equation and Elovich equation could well reflect the adsorption model.As well as，the correlation coefficient R2>0.99 in the entire stage，and the calculated equilibrium adsorption capacity qe=2.54 mg/g and the difference between the observed equilibrium adsorption capacity was 2.27 mg/g，which indicated that the pseudo-second-order kinetics equation could be more comprehensively describe the adsorption process of Cu-β/SBA-15 to dibenzothiophene and its controlled by both film diffusion and particle diffusion.