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过程工程学报 ›› 2020, Vol. 20 ›› Issue (1): 116-122.DOI: 10.12034/j.issn.1009-606X.219167

• 环境与能源 • 上一篇    

Zn改性对Ni/ZSM-22催化剂费托重柴油异构降凝性能的影响

白宜灵1,3， 范立闯3， 李 涛2， 陈会民2， 张怀科3， 杨 勇2,3， 张光晋1*   

  1. 1. 中国科学院过程工程研究所，北京100190 2. 中国科学院山西煤炭化学研究所，山西 太原 030001 3. 中科合成油技术有限公司，北京 101407
  • 收稿日期:2019-03-25 修回日期:2019-04-24 出版日期:2020-01-22 发布日期:2020-01-14
  • 通讯作者: 张光晋 zhanggj@home.ipe.ac.cn

Effect of Zn modification on hydroisomerization performance of the Fischer?Tropsch heavy diesel over Ni/ZSM-22 catalyst

Yiling BAI1,3, Lichuang FAN3, Tao LI2, Huimin CHEN2, Huaike ZHANG3, Yong YANG2,3, Guangjin ZHANG1*   

  1. 1. Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China 2. Institute of Coal Chemistry, Chinese Academy of Sciences, Taiyuan, Shanxi 030001, China 3. Synfuels China Technology Co., Ltd., Beijing 101407, China
  • Received:2019-03-25 Revised:2019-04-24 Online:2020-01-22 Published:2020-01-14
  • Contact: ZHANG Guang-jin zhanggj@home.ipe.ac.cn

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摘要： 采用离子交换、成型、负载方法对ZSM-22分子筛进行改性，得到不同Zn负载量的ZSM-22分子筛载体，通过X射线衍射、N2物理吸附?脱附及吡啶吸附红外等表征其物化性质。以改性ZSM-22分子筛为酸性组分、Ni为金属组分制备Ni基加氢异构催化剂，以费托重柴油为原料对其异构降凝性能进行评价。结果表明，离子交换对分子筛结构影响较小，且Zn在分子筛表面呈高度分散状。分子筛负载Zn可降低Br?nsted (B)酸与Lewis (L)酸的酸量比值(B/L)，且随Zn负载量增加，B/L值降低，异构烃收率提高，有效抑制裂解反应，提高柴油收率。负载Zn可明显降低重型柴油冷滤点，随Zn负载量逐渐提高，冷滤点上升。在金属加氢性能相同时，减少B酸含量有利于提升催化剂上金属位与酸性位的匹配及重型柴油异构性能。以所制Zn负载量为0.42wt%的Ni基分子筛催化剂在柴油的冷滤点达到国六车用柴油标准-10#柴油要求(冷滤点?5℃)时，柴油收率仍高达90.65%。

关键词: Zn改性, ZSM-22分子筛, 费托重柴油, 加氢异构

Abstract: The hydroisomerization catalyst is a metal-acid bifunctional catalyst that provides addition dehydrogenation function by metal component, and acidic component provides isomerization function. Hydroisomerization can effectively reduce oil pour point, provide low-temperature flow performance, and improve oil quality. The ZSM-22 zeolite was modified by ion exchange, molding and loading methods to obtain different Zn loadings. The physicochemical properties were characterized by X-ray diffraction (XRD), N2 physical adsorption-desorption (BET), X-ray fluorescence (XRF) and pyridine adsorption infrared (Py-IR). Ni-based hydroisomerization catalyst was prepared by using modified ZSM-22 zeolite as an acidic component and Ni as a metal component. The heterogeneous pour point depressing performance was evaluated by using Fischer–Tropsch heavy diesel oil as a raw material in the fixed bed reactor. Liquid and gas products were measured by off-line gas chromatography and on-line gas chromatography to calculate diesel yield. The results showed that ion exchange had little effect on the zeolite structure, and Zn species were highly dispersed on the surface of the zeolite. The Br?nsted (B) acid content of the catalyst had a significant effect on the activity. The higher B acid content, the higher activity of the catalyst. The introduction of Zn in the zeolite reduced the acidity ratio of B acid to Lewis (L) acid (B/L). With the increase of Zn content, the B/L value decreased, the yield of isomeric hydrocarbon increased, the cracking reaction was effectively inhibited, and the diesel yield was improved. Loading Zn could significantly reduce the cold filter point of heavy filter, and the cold filter point rose with Zn load content increased gradually. When the metal hydrogenation performance was the same, the matching of the metal and acid sites on the catalyst and the heterogeneous performance of the heavy diesel were improved with the decrease of B acid content. When the cold filter point of diesel reached the requirement of -10# diesel of China VI National Standard (cold filter point –5℃), the yield of prepared HI-3 catalyst reached 90.65%.

Key words: Zn modification, ZSM-22 zeolite, Fischer–Tropsch heavy diesel, Hydroisomerization