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    Alkali amino-polyacetate continuous prodn. - from formaldehyde, cyanide and opt. polyamine; using air aspiration to remove ammonia
    2.
    发明专利
    Alkali amino-polyacetate continuous prodn. - from formaldehyde, cyanide and opt. polyamine; using air aspiration to remove ammonia 未知

    公开(公告)号：DE2625974A1

    公开(公告)日：1977-12-22

    申请号：DE2625974

    申请日：1976-06-10

    Applicant: BASF AG

    Inventor： HOCK KARL-LUDWIG DIPL CHEM DR

    IPC: C07C101/20 ,  C07C99/00

    Abstract: In the continuous prodn. of alkali aminopolyacetates (I) from HCHO and alkali cyanide (II) and opt. non-aromatic di- or tri-amine (III) in aq. soln. at elevated temp. 2 consecutive reaction zones, the ammonia (IV) formed in all reaction zones is removed continuously with an air stream, which is sucked through all zones at 15-150 (pref. 15-80) mbar below the ambient pressure in an amt. of 50-150 vol./mole (II) per hr. The process is simple, operates at only very slightly reduced pressure, and gives (I) with a low content of impurities, i.e. a colour value of 30-50 APHA, cf. 100-150 APHA obtd. in the discontinuous process. In an example, ethylene diamine, aq. NaCN and aq. HCHO soln. were passed through a cascade of 5 reactors, with addn. of more NaCN and HCHO in the second, third and fourth reactors. (IV) was removed with air at a pressure reduced by 65 mbar; 95-96% pure tetra-Na salt of EDTE was obtd. in the form of a 45% aq. soln., free from cyanide, with a colour value of 50 APHA.

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