构筑Ni/ZnCo2O4@ZnO复合金属氧化物脱硫剂及其反应吸附脱硫-再生性能研究

Preparation of Ni/ZnCo2O4@ZnO composite metal oxide adsorbent and its adsorption desulfurization and regeneration performance

  • 摘要: 采用共沉淀法在ZnO中引入金属Co并使其形成复合金属氧化物,通过共沉淀-浸渍法构筑了不同Co含量的复合金属氧化物脱硫剂,考察其脱硫活性和再生性能。采用XRD、TEM、N2低温吸附-脱附、XPS和H2-TPR等对脱硫剂的结构和性质进行系统表征,证实得到了Ni/ZnCo2O4@ZnO结构的复合金属氧化物脱硫剂。复合金属氧化物脱硫剂中ZnCo2O4的形成有利于脱硫剂的颗粒尺寸减小、分散度提升、比表面积增大。反应后XRD显示,ZnCo2O4也可作为H2S的吸附剂,从而提高了脱硫剂的硫吸附容量。所有的复合金属氧化物脱硫剂的脱硫性能显著优于Ni/ZnO,其中,Zn∶Co物质的量比为1∶1的脱硫剂NZCo-3具有最优的脱硫性能,该脱硫剂在反应温度300 ℃,氢压3 MPa,质量空速2.2 h−1,氢油体积比300的条件下脱硫率为100%,且经过六次循环后仍能够保持优异的脱硫性能。该研究结果为合理设计Ni/ZnO脱硫剂以提高其脱硫性能和再生性能提供新的思路。

     

    Abstract: Metal Co was introduced into ZnO by co-precipitation to form composite metal oxides as the desulfurization agent with different Co contents, with which the desulfurization activity and regeneration performance were investigated. The systematic characterization of the structure and properties of the desulfurization agent using XRD, TEM, N2 adsorption and desorption, XPS and H2-TPR confirmed that the composite metal oxide desulfurization agent had the Ni/ZnCo2O4@ZnO structure. The formation of ZnCo2O4 in the composite metal oxides desulfurization agent facilitated the particle size reduction, dispersion enhancement and specific surface area increase of the desulfurization agent, which also acted as an adsorbent for H2S indicated by the XRD analysis, improving the sulfur adsorption capacity of the desulfurization agent. The desulfurization performance of all the composite metal oxide desulfurization agents was higher than that of Ni/ZnO, in which the desulfurization agent NZCo-3 with a molar ratio of Zn∶Co of 1∶1 exhibited the optimal desulfurization performance, and the desulfurization rate was 100% at a reaction temperature of 300 ℃, a hydrogen pressure of 3 MPa, a mass-air velocity of 2.2 h−1, and a hydrogen-oil ratio of 300, and the excellent desulfurization performance was maintained after 6 cycles. The results of this study provide new ideas for the rational design of Ni/ZnO desulfurization agent to improve its desulfurization and regeneration performance.

     

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