Membrane technology offers substantial economic and environmental benefits for energy-intensive chemical separations. Chabazite-type zeolite, possessing a 3-D channel system with molecular-sieving windows, can be an ideal membrane material, but conditions to synthesize zeolite-only membranes limit optimization strategies. Guided by advanced quantum chemistry calculations on inner-pore molecular interactions, zeolite properties are tailored for different separations and optimized particles incorporated in polyimide at very high loadings.
View Article and Find Full Text PDFMixed-matrix membranes (MMMs) have been investigated to render energy-intensive separations more efficiently by combining the selectivity and permeability performance, robustness, and nonaging properties of the filler with the easy processing, handling, and scaling up of the polymer. However, truly combining all in one single material has proven very challenging. In this work, we filled a commercial polyimide with ultrahigh loadings of a high-aspect ratio, CO-philic Na-SSZ-39 zeolite with a three-dimensional channel system that precisely separates gas molecules.
View Article and Find Full Text PDFIn this work we investigate the synthesis of alanine from lactic acid, a biobased platform chemical, using ammonia as a nitrogen source and Ru/zeolite catalysts. We report a high alanine selectivity when using Ru/BEA of 80-93%. Reaction side products were identified as ethanol, propionic acid or propanamide and the reaction mechanism was investigated.
View Article and Find Full Text PDF