Hollow fiber permeating and vaporizing film and preparation method

Abstract

The invention discloses a double-layer hollow fiber permeating and vaporizing film and a preparation method. The double-layer hollow fiber permeating and vaporizing film is characterized in that by controlling the formulas of a film casting liquid of an outer layer and a film casting liquid of an inner layer, the prepared double-layer hollow fiber permeating and vaporizing film is of a particularskin layer structure; a selective separating layer for hollow fiber permeating and vaporizing is arranged between an outer protecting layer and an inner support layer. The double-layer hollow fiber permeating and vaporizing film has the advantages that the outer protecting layer is used for protecting the selective separating layer, so that the separating efficiency and stability of the hollow fiber permeating and vaporizing film are improved; the hollow fiber permeating and vaporizing film is prepared by a one-step double-layer extruding technology, and the preparation technology is simple.

Description

technical field [0001] The invention relates to the field of pervaporation membranes, in particular to a hollow fiber pervaporation membrane and a preparation method thereof. Background technique [0002] Pervaporation (PV) is an emerging membrane separation technology. It uses the chemical potential difference between the upstream and downstream of a certain component of the feed liquid as the driving force to achieve mass transfer, and uses the membrane to have affinity for different components in the feed liquid. Selectivity can be achieved by the difference in property and mass transfer resistance. It can be used for the separation of azeotropes and near-boiling systems, the removal of trace water and the removal of trace organic matter in water, which are difficult to handle by traditional separation methods. It has high efficiency and energy saving. , simple process and environmental friendliness. Among them, the membrane is the core of the pervaporation separation pr...

AI Technical Summary

Problems solved by technology

However, these two pervaporation membranes also have their own defects in practical applications:

[0004] 1. The main defects of cross-linked polyvinyl alcohol film are: (1) The production process is complicated, and post-treatment processes such as coating and cross-linking are required; (2) The flux per unit area of ​​the film is small and the processing capacity is low; (3) The plate and frame membrane module has a small effective filling area per unit volume; (4) the membrane is easy to swell and the separation efficiency is low

[0005] 2. The main defects of zeolite molecular sieve inorganic membranes are: (1) The cost of materials is too high; (2) The production process is extremely complicated, and it is necessary to coat crystal grains on the inorganic base membrane and undergo a series of steps such as crystal growth and heat treatment, and the production cost High and long period; (3) Tubular membrane module, the effective filling area per unit volume is very small, and the processing capacity is low; (4) The molecular sieve selection layer is unstable and easy to hydrolyze

Images