煤 /重油加氢共炼中SDBS对煤担载铁镍催化剂的改性效果

以广西褐煤为载体煤,铁盐和镍盐为活性组分,考察了以十二烷基苯磺酸钠(SDBS)作为表面活性剂,对沉淀-氧化法制备煤担载型铁镍催化剂(FeNi/C)的影响以及制备的催化剂在煤/重油加氢共炼中的反应性能。采用XRD和TEM分析了FeNi和FeNi-SDBS的物相组成与微观形貌变化,并以SEM-mapping手段对比了Fe元素和Ni元素在FeNi/C及FeNi-SDBS/C表面的分散效果,采用高压釜实验评价了不同催化剂的反应性能,并对反应后的固体产物采用元素分析、FTIR和SEM进行组成和结构性质研究。结果表明:SDBS的加入显著降低了催化剂的平均粒径,α/γ-FeOOH和Fe0.67Ni0.33OOH等活性相的晶体结构特征减弱,在载体煤上得到了更好的分散效果;FeNi-SDBS/C催化剂相比FeNi/C催化剂有更高的油收率和干基无灰煤转化率,催化活性明显提高;采用SDBS改性的催化剂反应后得到固体产物的n(H)∶n(C)高、脂肪链长度低、芳环取代度大、结构疏松且平均粒径小,表面改性后的FeNi-SDBS/C催化剂拥有更强的促进煤加氢转化和抑制体系缩合生焦的作用。

Effect of SDBS on Modification of Coal-supported Iron-nickel Catalyst in Hydro-coprocessing of Coal and Heavy Oil

A kind of Guangxi lignite and iron and nickel salts were selected as support and active components, respectively, to investigate the influence of SDBS on the preparation of FeNi catalyst loaded on the coal(FeNi/C) via the sedimentation-oxygenation method and the reaction performance in the hydro-processing of lignite and heavy oil. Phase composition and micromorphology feature variations of FeNi and FeNi-SDBS catalysts were analyzed by using XRD and TEM. The dispersion effectiveness of Fe and Ni on the surface of FeNi/C and FeNi-SDBS/C was compared in terms of SEM-mapping. Reaction performance of different catalysts was evaluated in an autoclave, and the composition and structure properties of solid products were analyzed by using ultimate analysis, FTIR and SEM. Experimental results show that the average particle size of catalyst is reduced significantly, and the crystal characteristics of active phases of α/γ-FeOOH and Fe0.67Ni0.33OOH are weaken, whereas the dispersion of Fe and Ni on the supported coal is improved. FeNi-SDBS/C catalyst outperform the FeNi/C catalyst, with a higher oil yield and conversion efficiency, exhibiting the significant enhancement of the catalytic activity. The high n(H)∶n(C), low aliphatic chain length, high substitution degree in the aromatic rings, unconsolidated structure feature and small average particle size of the solid product are attributable to the modification of SDBS, which indicates the enhanced promotion effect on the coal hydro-conversion and the inhibition of condensation and coke formation in the reaction system.