| 摘要 |
<p>PROBLEM TO BE SOLVED: To increase the mol.wt. of ethylenic polymer by installing a fixed bed-type adsorption tower filled with an adsorbent such as a zeolite or the like between a separator and a compressor in a low-press. recycle process and/or between a separator and a secondary compressor in a high-press. recycle process, and consequently, by removing impurities. SOLUTION: By newly installing an adsorbent-filled apparatus to a high-press. polymerizer for ethylenic polymer prepn., remained impurities which are unable to be removed by a separator and work as a chain transfer and consequently reduce the mol.wt. of ethylenic polymer, are removed. As the adsorbent, a zeolite, activated aluminum, and activated carbon are cited. The operation condition for an adsorption tower, preferably. The press. is 30-260 kg/cm<2> , and the temp. is 60 deg.C or below. For adsorption removal, at least one of a low-press. recycle process and a high-press. recycle process are utilized, however, the both together use can achieve larger effect. A high-press. process with a reaction press. of 400-4,000 kg/cm<2> and a high concn. operation of vinyl acetate gains more considerable effect.</p> |
