Preparation method of ion-doped cellulose gas separation membrane and cellulose gas separation membrane

Abstract

The invention discloses a preparation method of an ion-doped cellulose gas separation membrane and a cellulose gas separation membrane. The preparation method comprises the following steps: preparinga metal salt liquid: preparing a mixed aqueous liquid of ZnCl2 and an inorganic metal salt; preparing a cellulose liquid: dissolving cellulose raw materials in the prepared metal salt liquid, and heating; scraping a membrane, and performing solidification: scraping the membrane on a substrate after vacuum defoaming to form a liquid layer, and soaking in a coagulation bath. The regenerated cellulose membrane prepared with the method is used for CO2 / O2, and CO2 / N2 separation, the separation factor for CO2 / N2 reaches 30 or more, and the separation factor for CO2 / O2 reaches 100 or more. Accordingto the invention, the loading of ions is realized by utilizing the salt liquid containing metal ions to dissolve the cellulose, coordination bonds exist between the ions and the cellulose, and the ions are high in content, uniform in distribution, and stable.

Description

technical field

[0001] The invention belongs to the technical field of cellulose membrane preparation, and in particular relates to a preparation method of an ion-doped cellulose gas separation membrane and the cellulose gas separation membrane. Background technique

[0002] with CO 2 The massive emission of greenhouse gases, which are the main ones, has aggravated the greenhouse effect and caused global warming, which has become one of the most concerned environmental issues in the world. Therefore, CO 2 The separation and recovery of waste has become the focus of everyone's attention. The existing membrane separation method is widely used due to the advantages of low cost, high efficiency, simple process and high reliability. Membrane technology is used for CO 2 / CH 4 and CO 2 / N 2 The separation has been more than 30 years old. Although metal ions can act as a catalyst for CO 2 Carriers for transport, however, to achieve high loadings of metal ions in membranes in...

Examples

Embodiment 1

[0031] Weigh 9.87g ZnCl 2 and 0.48g CaCl 2 Put it into a beaker, add deionized water to 15.00g, configure it as a mixed salt solution, add 0.25g of cotton linters (the degree of polymerization is in the range of 200-2000), heat to 80°C, and stir for 2 hours to obtain a uniform cellulose Solution, after vacuum degassing, scrape the film on the substrate to form a solution layer of 0.1 mm, soak it in an isopropanol coagulation bath for 10 minutes after vacuum degassing, shape it with a jig, dry it in the air, and store it in an airtight container to obtain a transparent Regenerated cellulose gas separation membrane. Its visible spectrum and physical photos are as follows: figure 1 shown, from figure 1 It can be seen that the high transmittance in the visible light region indicates its optical transparency, and the foldability indicates its good flexibility. The metal ion content and gas permeability of the regenerated cellulose membrane are listed in Table 1.

Embodiment 2

[0035] Weigh 15.00g ZnCl 2 and 1.00g CoCl 2Put it into a beaker, add deionized water to 20.00g, configure a mixed salt solution, add 0.61g of absorbent cotton (the degree of polymerization is in the range of 200-2000), heat at 70°C, and stir for 1 hour to obtain a uniform cellulose solution , after vacuum degassing, scrape the film on the substrate to form a solution layer of 0.2 mm, soak in methanol coagulation bath for 20 minutes after vacuum degassing, set the shape with the fixture, dry in the air, store in a closed container, and obtain transparent regenerated cellulose Membrane, its surface and cross-section photographs are shown in figure 2 shown, from figure 2 It can be seen that the surface and cross section of the product of the present invention are smooth and smooth without defects. The metal ion content and gas permeability of the regenerated cellulose membrane are listed in Table 1.

Embodiment 3

[0039] Weigh 6.88g ZnCl 2 and 0.70g ZrOCl 2 Put it into a beaker, add deionized water to 12.0g, configure it as a mixed salt solution, add 0.95g of microcrystalline cellulose (the degree of polymerization is in the range of 200-2000), heat at 55°C, and stir for 20 minutes to obtain a uniform Cellulose solution, after degassing, scrape the film on the substrate to form a solution layer of 0.3mm, soak in an acetone coagulation bath for 30 minutes after vacuum degassing, shape it with a jig, dry it in the air, and store it in an airtight container to obtain a transparent regenerated fiber The plain film, its metal ion content and gas permeability are listed in Table 1. image 3 It is a comparison chart of thermogravimetric curves of the prepared regenerated cellulose film and cellulose raw material. The solid line is the cellulose raw material, the dotted line is the regenerated cellulose film, from image 3 It can be seen that two-step decomposition: from about 50 °C to 200 °...

technical field

[0001] The invention belongs to the technical field of cellulose membrane preparation, and in particular relates to a preparation method of an ion-doped cellulose gas separation membrane and the cellulose gas separation membrane. Background technique

[0002] with CO 2 The massive emission of greenhouse gases, which are the main ones, has aggravated the greenhouse effect and caused global warming, which has become one of the most concerned environmental issues in the world. Therefore, CO 2 The separation and recovery of waste has become the focus of everyone's attention. The existing membrane separation method is widely used due to the advantages of low cost, high efficiency, simple process and high reliability. Membrane technology is used for CO 2 / CH 4 and CO 2 / N 2 The separation has been more than 30 years old. Although metal ions can act as a catalyst for CO 2 Carriers for transport, however, to achieve high loadings of metal ions in membranes in...

Examples

Embodiment 1

[0031] Weigh 9.87g ZnCl 2 and 0.48g CaCl 2 Put it into a beaker, add deionized water to 15.00g, configure it as a mixed salt solution, add 0.25g of cotton linters (the degree of polymerization is in the range of 200-2000), heat to 80°C, and stir for 2 hours to obtain a uniform cellulose Solution, after vacuum degassing, scrape the film on the substrate to form a solution layer of 0.1 mm, soak it in an isopropanol coagulation bath for 10 minutes after vacuum degassing, shape it with a jig, dry it in the air, and store it in an airtight container to obtain a transparent Regenerated cellulose gas separation membrane. Its visible spectrum and physical photos are as follows: figure 1 shown, from figure 1 It can be seen that the high transmittance in the visible light region indicates its optical transparency, and the foldability indicates its good flexibility. The metal ion content and gas permeability of the regenerated cellulose membrane are listed in Table 1.

Embodiment 2

[0035] Weigh 15.00g ZnCl 2 and 1.00g CoCl 2Put it into a beaker, add deionized water to 20.00g, configure a mixed salt solution, add 0.61g of absorbent cotton (the degree of polymerization is in the range of 200-2000), heat at 70°C, and stir for 1 hour to obtain a uniform cellulose solution , after vacuum degassing, scrape the film on the substrate to form a solution layer of 0.2 mm, soak in methanol coagulation bath for 20 minutes after vacuum degassing, set the shape with the fixture, dry in the air, store in a closed container, and obtain transparent regenerated cellulose Membrane, its surface and cross-section photographs are shown in figure 2 shown, from figure 2 It can be seen that the surface and cross section of the product of the present invention are smooth and smooth without defects. The metal ion content and gas permeability of the regenerated cellulose membrane are listed in Table 1.

Embodiment 3

[0039] Weigh 6.88g ZnCl 2 and 0.70g ZrOCl 2 Put it into a beaker, add deionized water to 12.0g, configure it as a mixed salt solution, add 0.95g of microcrystalline cellulose (the degree of polymerization is in the range of 200-2000), heat at 55°C, and stir for 20 minutes to obtain a uniform Cellulose solution, after degassing, scrape the film on the substrate to form a solution layer of 0.3mm, soak in an acetone coagulation bath for 30 minutes after vacuum degassing, shape it with a jig, dry it in the air, and store it in an airtight container to obtain a transparent regenerated fiber The plain film, its metal ion content and gas permeability are listed in Table 1. image 3 It is a comparison chart of thermogravimetric curves of the prepared regenerated cellulose film and cellulose raw material. The solid line is the cellulose raw material, the dotted line is the regenerated cellulose film, from image 3 It can be seen that two-step decomposition: from about 50 °C to 200 °...

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