| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To construct a method for producing meta-xylene of a purity of at least 99.5% by combining a simulated moving-bed adsorption step and a crystallization step to separate the meta-xylene. <P>SOLUTION: The simulated moving-bed adsorption step (LM3) is operated under a mild condition and the purity of the meta-xylene discharged from the adsorbing apparatus is low, generally 75% to 99%. The apparatus has high productivity (amount of meta-xylene produced per unit volume of an adsorbent per unit time) and a raw material is rich in ortho-xylene (for example, 10% or higher) which lead to a decrease of the ratio of a solvent to the raw material. The yield in the crystallization (CD6, CD12) step is improved by concentrating the coming raw material in advance. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
