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公开(公告)号：MY117551A
公开(公告)日：2004-07-31
申请号：MYPI9700437
申请日：1997-02-05
Applicant: BASF AG
Inventor： ALEXANDER WECK D I FH , TONI DOCKNER DR , MATTHIAS GEISENDORFER DR , HOLGER HERBST DR , GERHARD NESTLER DR , WILLI SCHMIDT
Abstract: IN A PROCESS FOR THE CONTINUOUS PREPARATION OF ALKYL ESTERS OF (METH)ACRYLIC ACID BY REACTION (METH)ACRYLIC ACID WITH ALKANOLS HAVING FROM 1 TO 8 CARBON ATOMS IN A HOMOGENEOUS, LIQUID, SOLVENT-FREE PHASE AT ELEVATED TEMPERATURE AND IN THE PRESENCE OF AN ACID ESTERIFICATION CATALYST, IN WHICH THE (METH)ACRYLIC ACID, THE ALKANOL AND THE ACID CATALYST ARE FED TO A REACTION ZONE (5,6), THE WATER FORMED IS REMOVED BY RECTIFICATION DURING A RESIDENCE TIME AS CONSTITUENT OF A MIXTURE COMPRISING STARTING ALKANOL IN A RECTIFICATION UNIT (III) SUPERPOSED ON THE REACTION ZONE (5,6), THE DISTILLATE OBTAINED IS SEPARATED INTO AN ORGANIC PHASE COMPRISING ALKANOL AND AN AQUEOUS PHASE COMPRISING WATER, THE ORGANIC PHASE IS ESSENTIALLY COMPLETELY RETURNED TO THE RECTIFICATION UNIT (III), THE REACTION MIXTURE IS DISCHARGED FROM THE REACTION ZONE (5,6) AND CONVEYED INTO A DISTILLATIVE SEPARATION ZONE COMPRISING FURTHER RECTIFICATION UNITS (I,II) AND IN THE LATER THE ALKYL (METH)ACRYLATE FORMED IS SEPARATED OFF. A) (METH)ACRYLIC ACID AND ALKANOL ARE REACTED IN A MOLAR RATIO OF FROM 1 :0.75 TO 1 :2, B) PART OF THE AQUEOUS PHASE OBTAINED AT THE TOP OF THE RECTIFICATION UNIT (III) IS RETURNED TO THE RECTIFICATION UNIT, C) THE REACTION MIXTURE DISCHARGED FROM THE REACTION ZONE IS FED TO A FURTHER RECTIFICATION UNIT (I) AND IN THIS THE REACTION MIXTURE IS SEPARATED INTO A PRODUCT (II) COMPRISING THE CATALYST AND A PRODUCT (I) COMPRISING THE ALKYL ESTER OF (METH) ACRYLIC ACID, REMAINING ALKANOL AND REMAINING (METH)ACRYLIC ACID, AND D) THE PRODUCT (I) IS FED TO A FURTHER RECTIFICATION UNIT (II) AND IN THIS THE ALKYL ESTER OF (METH)ACRYLIC ACID IS SEPARATED FROM THE REMAINING ALKANOL AND FROM THE REMAINING (METH)ACRYLIC ACID AND THE REMAINING ALKANOL AND THE REMAINING (METH)ACRYLIC ACID ARE RETURNED TO THE REACTION ZONE.
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公开(公告)号：CZ9700309A3
公开(公告)日：1997-10-15
申请号：CZ30997
申请日：1997-02-03
Applicant: BASF AG
Inventor： SCHMIDT WILLI , MATTHIAS GEISENDORFER DR , DOCKNER TONI DR , HERBST HOLGER DR , NESTLER GERHARD DR
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公开(公告)号：CZ30997A3
公开(公告)日：1997-10-15
申请号：CZ30997
申请日：1997-02-03
Applicant: BASF AG
Inventor： SCHMIDT WILLI , MATTHIAS GEISENDORFER DR , DOCKNER TONI DR , HERBST HOLGER DR , NESTLER GERHARD DR
Abstract: In the continuous production of alkyl (meth)acrylates (AA) by reacting (meth)acrylic acid with 1-8 carbon (C) monohydric alkanols in homogeneous liquid phase, free from solvent, at elevated temperature and in the presence of an acid esterification catalyst; (a) (meth)acrylic acid, alkanol and catalyst are fed to a reaction zone; (b) during a residence time, the water formed is separated in a rectification unit (RU) III above the reaction zone; (c) the aqueous distillate is separated into an organic phase containing the alkanol and an aqueous phase; (d) the organic phase is recycled to RU III; and (e) the reaction mixture is discharged from the reaction zone and passed to another RU, where AA is separated by distillation. The novel features are that: (i) the molar ratio of (meth)acrylic acid and alkanol is 1:(0.75-2); (ii) the aqueous phase from RU III is partly recycled to RU III; (iii) the reaction mixture is passed to RU I, in which it is separated into a product (II) containing the catalyst and a product (I) containing AA, residual alkanol and residual (meth)acrylic acid; and (iv) (I) is passed to RU II, in which AA is separated from residual alkanol and residual (meth)acrylic acid and the alkanol and acid are recycled to the reaction zone. Preferably the alkanol is 2-ethylhexanol. The catalyst is para-toluenesulphonic acid (p-TSA) and/or other organic sulphonic acids, e.g. methane-, benzene- or dodecylbenzene-sulphonic acid, and/or sulphuric acid (H2SO4). The catalyst concentration in the reaction mixture is 0.1-10, especially 0.1-6 wt.% p-TSA in the reaction zone and 2.5-50 wt.% p-TSA in the sump or an equimolar amount of organic sulphonic acid and/or H2SO4. The reaction zone consists of a cascade of NOTLESS 2, especially 2-4 consecutive sections, especially reactors with circulating vapourisers. All rectification units are rectification columns.
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