JP2000178375A5

JP2000178375A5 -

Info

Publication number: JP2000178375A5
Application number: JP1998356030A
Authority: JP
Filing date: 1998-12-15
Publication date: 2004-08-26

Description

【００２２】
そこで、濾過体が目詰まりを起こし、入口と出口の差圧が一定圧力以上となったときに、濾過体を逆洗処理する。逆洗を行うべき差圧は濾過体の種類や除去すべき不溶性不純物の種類、粒径等により異なるが通常０．１〜１．０ＭＰａの範囲が好適に用いられる。逆洗処理の媒体としては２００〜５００℃の超臨界水または亜臨界水を用いる。逆洗処理媒体の温度が２００℃を下回るとテレフタル酸などの析出による濾過体の目詰まりが生じ５００℃を超えると例えばテレフタル酸の脱炭酸やエチレングリコールの縮合などの副反応を生じてモノマーの収率が低下する。逆洗処理の媒体として超臨界水または亜臨界水を用いることにより、テレフタル酸等の常温下で固体であるようなモノマーの固化が防止できるため、濾過面や配管を閉塞することがない。[0022]
Therefore, when the filter body is clogged and the pressure difference between the inlet and the outlet becomes equal to or higher than a predetermined pressure, the filter body is backwashed. Differential pressure to be subjected to backwashing kind or type of insoluble impurities to be removed of the filter body, varies depending particle diameters usually in the range of 0.1~1.0MPa is used to good suitable. Supercritical water or subcritical water at 200 to 500 ° C. is used as a medium for the backwashing treatment. When the temperature of the backwashing medium is below 200 ° C., clogging of the filter body occurs due to precipitation of terephthalic acid etc. When it exceeds 500 ° C., side reactions such as decarboxylation of terephthalic acid and condensation of ethylene glycol occur, resulting in monomers The yield is reduced. By using supercritical water or subcritical water as a medium for the backwashing treatment, solidification of monomers such as terephthalic acid which is solid at normal temperature can be prevented, and therefore, the filtration surface and piping are not clogged.

【００３５】
遠心分離器８で分離された液体分としての水は、蒸留器１０へ供給される。分離水は蒸留器１０で蒸留され、蒸留物は、メタノール等の低沸点有機溶媒および／または有機酸等の不純物を含む水と、重質分を含むエチレングリコールとに回収される。[0035]
Water as a liquid fraction separated by the centrifugal separator 8 is supplied to the distiller 10. The separated water is distilled in a distiller 10, and the distillate is recovered into water containing a low boiling point organic solvent such as methanol and / or an impurity such as an organic acid and ethylene glycol containing a heavy component.

【００３８】
水は、反応器３から分解生成物と共に処理流体として流出し、濾過体４、遠心分離器８、蒸留器１０、水処理装置１２、冷却器６、加熱ボイラ１５を経て、反応器３に送入され、この経路で循環する。[0038]
Water flows out as the processing fluid with decomposition products from the reactor 3, the filter body 4, a centrifugal separator 8, distiller 10, the water treatment device 1 2, cooler 6, through the heating boiler 15, the reactor 3 It is sent in and circulates through this route.

【００４６】
また、重縮合系ポリマーの分解処理装置から流出した廃水を河川または公共下水に排出するために、従来は必要であった廃水処理設備が不要になり、その設備費および運転費を省くことができるので、モノマーの回収コストを一層低減することができる。[0046]
Further, the waste water flowing out of the decomposition treating apparatus of the polycondensation polymers to be discharged into rivers or public sewage, conventionally becomes unnecessary wastewater treatment facilities were required, its capital and operating costs of omit- ted As it is possible, the cost of recovering the monomer can be further reduced.