Study on Concentrate Tannin from Gallnut Extract by Membrane Integrated Method

Gallnut products are widely used in pharmaceutical, chemical, food, printing, aerospace, national defense and microelectronics industries due to their irreplaceable superiorities. In this paper, membrane separation technology was used to concentrate the tannin in the gall extract. Separation efficiency was investigated by different NF and RO membrane model, and the optimized purity of extracted tannin was 98% with yield of 97.5% that achieve the industrial tannin standards. Moreover, the flux capacity of membrane can be restored by corresponding cleaning solution.