Songbo He, Hero Reinder Goldhoorn, Zhuorigebatu Tegudeer, Anshu Chandel, Andre Heeres, Chuncheng Liu, Evgeny Pidko, Hero Jan Heeres*

Fuel Processing Technology, 2021, 221:106944.

https://doi.org/10.1016/j.fuproc.2021.106944

ABSTRACT: The use of H-ZSM-5 with various binders (Al₂O₃, SiO₂, and kaolinite, 10 wt% on catalyst formulation) for the catalytic conversion of glycerol to bio-based aromatics (GTA) was investigated in a continuous bench-scale unit at a pyrolysis temperature of 450 °C, catalytic upgrading temperature of 500 °C, WHSV of pure glycerol of 1 h⁻¹, and atmospheric pressure, and their performance was compared to H-ZSM-5 (SiO₂/Al₂O₃ molar ratio of 28). The latter gave a peak BTX carbon yield of ca. 31.1C.%, a life-time of ca. 220 min, and a total BTX productivity of ca. 312 mgBTX g⁻¹H-ZSM-5. The introduction of binders affects catalyst performance, which is the most profound and promising for the H-ZSM-5/Al₂O₃ catalyst. It shows a prolonged catalyst life-time of ca. 320 min and a higher total BTX productivity of ca. 518 mgBTX g⁻¹H-ZSM-5, compared to the H-ZSM-5 without a binder. Catalyst characterization studies show that the addition of the binder does not have a major effect on the specific surface area, total pore volume, and total acidity. Other relevant properties were affected, though, such as micropore volume (SiO₂), a reduced Brønsted acidity (Al₂O₃, and SiO₂), and reduced crystallinity (SiO₂). Coke formation causes severe catalyst deactivation, ultimately leading to an inactive catalyst for BTX formation. Catalyst characterization studies after an oxidative regeneration showed that the textural properties of the regenerated catalysts were close to those of the original catalysts. However, some dealumination of H-ZSM-5 occurs, resulting in decreased crystallinity and acidity, causing irreversible deactivation, which needs attention in future catalyst development studies.

摘要：

本研究在连续中型装置上考察了以不同粘结剂（Al₂O₃、SiO₂和高岭土，占催化剂配方10 wt%）与H-ZSM-5（SiO₂/Al₂O₃摩尔比为28）结合用于催化甘油转化为生物基芳烃（GTA）的性能，反应条件为：热解温度450 °C、催化升级温度500 °C、纯甘油重量空速1 h⁻¹、常压。未添加粘结剂的H-ZSM-5催化剂获得约31.1碳收率%的BTX峰值碳收率，寿命约220分钟，总BTX产率约312 mgBTX/g H-ZSM-5。粘结剂的引入影响催化剂性能，其中H-ZSM-5/Al₂O₃催化剂表现最为突出：其寿命延长至约320分钟，总BTX产率提高至约518 mgBTX/g H-ZSM-5。表征研究表明，粘结剂的添加对比表面积、总孔体积和总酸量影响不大，但会影响其他关键性质：SiO₂降低微孔体积，Al₂O₃和SiO₂降低布朗斯特酸量，SiO₂还降低结晶度。积碳是导致催化剂严重失活的主因，最终使催化剂丧失生成BTX的活性。氧化再生后的表征显示，再生催化剂的织构性质接近原始催化剂，但H-ZSM-5发生一定程度的脱铝，导致结晶度和酸量下降，引起不可逆失活，这在未来催化剂开发中需予以关注。