Synthesis of HZSM-5 zeolites with excellent DME aromatization properties by orthogonal test

Abstract

The synthesis conditions of HZSM-5 zeolite, including crystallization temperature, crystallization time and raw material ratio, were investigated by L₃₂ (4⁸) orthogonal test to specifically optimize its performance in dimethyl ether (DME) aromatization for the first time. Based on the total yield of aromatic products, the synthesis conditions of HZSM-5 zeolite with the best DME aromatization properties were obtained by comprehensive analysis and validation experiments. The relationship between the aromatization performance, crystalline structure, pore structure, and acidity of HZSM-5 zeolite were analyzed. The results showed that the HZSM-5 zeolite accompanied by hierarchical structure, an appropriate Brønsted and Lewis acid content and uniform crystal morphology, was successfully synthesized under optimized conditions. Over this unmodified and un-doped catalyst, the conversion of DME approached to 99.3% and the total yield of aromatics reached was 53.5%.

Graphical Abstract

Keywords:

• DME aromatization
• HZSM-5 zeolite
• orthogonal test
• hierarchical structure

Additional information

Funding

This work was supported by the National Fund Cultivation Project of Shantou University under Grant NFC 15001; Subject and Specialty Construction Special Fund of Guangdong Provincial Higher Education Institution under Grant 2012CXZD0024, 2013KJCX0081; and Science and Technology Planning Project of Guangdong Province of China 2014A020216045, 180917104960483.