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A novel molecular sieve membrane was synthesized using graphene oxide/single-walled carbon nanotubes (GO/SWCNTs). The composite was characterized by transmission electron microscopy, field emission scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller-specific surface area analyzers. The results revealed that laminar GO was interwoven with tubular SWCNTs and the carbon nanotubes were attached onto the surface of GO or interspersed among GO to form a three-dimensional structure. Moreover, the interlayer spacing of GO/SWCNTs increased to 0.826 nm. On condition that the inlet pressure of N2 was 0.10 MPa and the temperature was 323 K, the N2 permeability of GO/SWCNTs was 1595 Barrer. With increasing temperature, the N2 permeability decreased while it increased with the inlet pressure. When the inlet pressure of CO was 0.10 MPa and the temperature was 323 K, the CO permeability was 109 Barrer. At the temperature of 323 K, the selectivities of N2/CO and CO2/CO were 32.8 and 37, respectively. These results indicated that GO/SWCNTs may be a promising molecular sieve for gas separation.

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The blast furnace gas separated by a membrane has a higher content of combustible components. In order to explore its secondary utilization in blast furnace production, numerical simulation is conducted by means of Fluent software, and the model is verified by experimental data. Results show that when the blast furnace gas separated by the membrane is used as pulverized coal carrier gas for blast furnace injection, the gas velocity in the furnace evidently increases, and the maximum injection velocity can reach 279 m s −1 . The formed high-temperature zone is closer to the centre of the blast furnace than those in the single injection of pulverized coal and in pulverized coal injection with general blast furnace gas as a carrier gas. The maximum temperature reaches 2610 K. Moreover, the pyrolysis reaction of pulverized coal is in advance, whereas the burnout rate of pulverized coal in the raceway presents a double-peak phenomenon.