▎ 摘　　要

NOVELTY - Preparing carbon dioxide by purifying liquid carbon dioxide comprises (i) transferring 99.5% liquid carbon dioxide in the cryogenic liquid storage tank to the high-purity liquid carbon dioxide purification device for the first purification, introducing purified carbon dioxide to the vaporizer for gasification, introducing vaporized carbon dioxide to the purifier for the secondary purification, and providing gas outlet pipe of the high-purity liquid carbon dioxide purification device with a gas-permeable membrane including 50-70 pts. wt. aromatic polyamide solution, 30-50 pts. wt. melamine derivatives, 1-2 pts. wt. nano-graphene, and 3-5 pts. wt. nano-silver; (ii) subjecting carbon dioxide to purification testing and testing, after passing the inspection, introducing purified carbon dioxide to the diaphragm compressor, pressurizing at 0-15 Mpa, and filling into a vacuum bottle; and (iii) testing carbon dioxide in the vacuum bottle, and qualifying and storing in the warehouse. USE - The method is useful for preparing carbon dioxide by purifying liquid carbon dioxide. ADVANTAGE - The method can meet the market's demand for carbon dioxide and realizes the requirement for the purity of carbon dioxide, so the purity of carbon dioxide reaches 99.999%. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic representation of the preparation of carbon dioxide by purifying liquid carbon dioxide (Drawing includes non-English language text).