Fabrication of hydrophilic and durable Beta zeolite membranes for dehydration of fuel n-butanol by adjusting Al spatial distribution

• Published in: Separation and purification technology 2024-12, Vol.351, p.128047, Article 128047
• Main Authors: Wu, Xiaowei, Li, Yuqin, Li, Yu, Peng, Mingyu, Yang, Zhengquan, Gui, Tian, Chen, Xiangshu, Kita, Hidetoshi
• Format: Article
• Language: English
• Subjects: Al spatial distribution; Beta zeolite membrane; Dehydration of n-butanol; Hydrophilicity; Long-term acid stability
• ISSN: 1383-5866
• DOI: 10.1016/j.seppur.2024.128047

[Display omitted] •A simple synthesis parameter adjustment strategy was proposed to modulate Al spatial distribution.•Beta zeolite membranes with high Al spatial distribution showed hydrophilic and durable properties.•The membrane was used in continuous dehydration to obtain anhydrous n-butanol (99.9 wt%).•The membrane showed long-term acid stability in dehydration of organic solvents with a pH of ca. 2.0. Highly hydrophilic and durable Beta zeolite membranes with high aluminum (Al) spatial distribution were synthesized on inexpensive α-alumina supports via an organic template-free synthesis gel. In the absence of organic templates, the Al spatial distribution of Beta zeolite membrane crystal was regulated by the synthesis parameters such as the Al2O3/SiO2 ratio, alkalinity, H2O/SiO2 ratio and crystallization temperature, and the crystal morphology, Si/Al ratio and dehydration performance of the membrane could be further effectively controlled. Under optimal synthesis conditions, the prepared Beta zeolite membrane had an excellent separation factor of over 22,000 and a high permeation flux of 3.02 kg m−2 h−1 in the case of a 90 wt% n-butanol/water mixture at 75 °C. The high-performance Beta zeolite membrane was applied for continuous dehydration to obtain anhydrous n-butanol (99.9 wt%) from a 90 wt% n-butanol/water mixture. Furthermore, Beta zeolite membranes showed long-term acid stability in pervaporation dehydration of a 90 wt% n-butanol/water mixture with a pH value of approximately 2.0 at 75 °C for 192 h, indicating that these membranes by adjusting Al spatial distribution exhibited excellent hydrophilicity and acid resistance, which had a broad promising prospect of industrial applications for dehydration separation of acid-containing organic solvents.