Molecular sieve pervaporation membrane uses molecular sieve as the membrane material, and uses its regular channels to separate different components. NaA-type inorganic molecular sieve pervaporation membrane is formed by NaA-type molecular sieve particles on the tubular ceramic porous support, through crystal growth (growth) to form a layer of tightly packed membrane layer, the pore diameter is about 4.2A, which is larger than the dynamic diameter of water molecules ( ~2.9A) and smaller than the molecular diameter of most organic compounds, showing good shape selectivity for water molecules; on the other hand, the high aluminum content (Si/Al=1) in the molecular sieve framework makes it extremely affinity Water-based, making NaA-type inorganic molecular sieve pervaporation membranes especially suitable for dehydration of organic solvents.
According to the characteristics of the material system to be separated, the molecular sieve membrane with controllable performance is prepared through the pretreatment of the ceramic support, the control of the crystal seed, the crystal coating method, the composition of the membrane synthesis raw material, and the parameters of the membrane synthesis process.
At 75°C, for 90 wt% ethanol feed, the separation coefficient of the prepared membrane was >10000, and the membrane permeation flux was >3 kg/m 2 h. Product performance has reached the international advanced level.
NaA molecular sieve membrane SEM