| 摘要 |
In a production method in which an acrylic acid-containing solution obtained from an acrylic acid-containing gas (or an acrylic acid-containing liquid obtained simply by subjecting the acrylic acid-containing solution to a separation process of reaction by-products) is directly subjected to a crystallization process, the crystallization process can't be carried out smoothly in an unsteady state (when the concentration of water in the acrylic acid-containing solution is high). The present invention aims to provide a method for collecting the purified acrylic acid having high purity in good yield even in an unsteady state. When the acrylic acid-containing solutions 18 and 16 have a concentration of water higher than 10 mass % (unsteady state), the purified acrylic acid 20 and 22 or the acrylic acid-containing solution 23 containing 10 mass % or less of water is mixed therewith to make the concentration of water 10 mass % or less [a] [b]. Alternatively, when the acrylic acid-containing solutions 18 and 16 have a concentration of water higher than 10 mass %, it is used as an absorption liquid [c]. Thereafter, the crystallization process is carried out.
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