Process for isolating acrylic acid from aqueous crude acrylic acid by extraction with a ketone and plural stage distillation
    1.
    发明授权
    Process for isolating acrylic acid from aqueous crude acrylic acid by extraction with a ketone and plural stage distillation 失效
    使用酮和提取液进行萃取,从水溶液中分离丙烯酸的方法

    公开(公告)号:US3689541A

    公开(公告)日:1972-09-05

    申请号:US3689541D

    申请日:1971-01-18

    摘要: Pure acrylic acid is isolated from an aqueous crude acid containing acrylic acid together with minor proportions of acetic acid, formaldehyde and high boilers boiling at a temperature higher than 220*C by liquid-liquid extraction with the use of 3,3,5-trimethylcyclohexanone and/or isophorone as the extractant(s). To this end, the aqueous acrylic acid-containing crude acid is subjected in an extraction zone to counterflow extraction with the use of the extractant(s) and with the resultant formation of an organic extract containing acrylic acid, acetic acid, high boilers and minor proportions of water, which are dissolved in the extractant; the extract is introduced approximately into the midsection of a first distilling column, which is operated under reduced pressure; the base product of said first distilling column, containing the high boilers and the extractant(s) is recycled to the extraction zone; distillate containing acrylic acid, acetic acid, water and minor proportions of extractant(s) is delivered approximately to the midsection of a second distilling column, which is operated under reduced pressure; a mixture of water and extractant(s) is distilled off; the base product of said second distilling column, containing acrylic acid and acetic acid is introduced into a third distilling column, which is operated under reduced pressure; and acetic acid is separated therein as a distillate and acrylic acid is separated therein as the base product.

    摘要翻译: 将纯丙烯酸与含有丙烯酸的含水粗酸以及少量乙酸,甲醛和高沸点沸点的高沸点物质分离,通过液 - 液萃取,使用3,3,5-三甲基环己酮 和/或异佛尔酮作为萃取剂。 为此,将含水丙烯酸的粗酸在萃取区中进行,使用萃取剂进行逆流萃取,形成含有丙烯酸,乙酸,高沸点和次要的有机萃取物 溶解在萃取剂中的水的比例; 将提取物大致引入到在减压下操作的第一蒸馏塔的中部; 含有高锅炉和萃取剂的所述第一蒸馏塔的基础产物被再循环到萃取区; 含有丙烯酸,乙酸,水和少量萃取剂的馏出物大致运送到减压下运行的第二蒸馏塔的中部; 蒸出水和萃取剂的混合物; 将含有丙烯酸和乙酸的所述第二蒸馏塔的基础产物引入在减压下运行的第三蒸馏塔中; 并将乙酸作为馏出物分离,丙烯酸作为基础产物分离。