| 摘要 |
<p>Recovery of (DMT) from a residue (obtd. as purge stream in mfr. of DMT from p-xylene) is carried out by mixing the H2O-and catalyst-free tarry fraction with a catalytic amt. of an alkali metal material (I) and heating the mixt. at 250-350 degrees C. (I) can be alkali metal or an alkali metal oxide hydroxide, carbonate, bicarbonate or carboxylate, esp. Na2CO3 or K2CO3; and is used in an amt. of 2ppm to 2% by wt. of the tarry fraction. The mixt. is pref. heated under reduced pressure (10-200 mm Hg) for 0.2-48 (esp. 2-18) hr. The process uses less expensive catalysts than prior art processes (c.f. JA48/39457, 48/96540, 49/11838 and 49/36648).</p> |
