Eco-friendly synthesis and environmental impact assessment of hierarchical Beta zeolite from kaolinite and recycled mother liquor

The development of sustainable techniques to produce high-performance zeolite is essential to achieve green production in industry. Herein, we report an eco-friendly route to synthesizing hierarchical Beta zeolite from kaolinite and recycled mother liquor. The results reveal that the unutilized species (such as silicon species and Na⁺) in mother liquor stayed in a stable concentration during eleven recycled experiments. Moreover, the synthesized Beta zeolites still have comparable physicochemical properties and catalytic performance in the esterification of levulinic acid with ethanol over the initial zeolite although eleven recycled experiments. Life cycle assessment exhibits that the synthesis of Beta zeolite with recycled mother liquor can reduce global warming potential by 23% and resource depletion-water use by 36% compared to that without recycled mother liquor. This quantitatively demonstrates that the approach proposed in this work is really a sustainable one, extremely increasing the utilization efficiency of raw materials and decreasing the environmental burden.