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    Pure racemic- and meso-tartaric acids prepd from alkali maleate - and hydrogen peroxide with alkali metal tungstate catalyst
    2.
    发明专利
    Pure racemic- and meso-tartaric acids prepd from alkali maleate - and hydrogen peroxide with alkali metal tungstate catalyst 未知

    公开(公告)号：DE2508228A1

    公开(公告)日：1976-09-09

    申请号：DE2508228

    申请日：1975-02-26

    Applicant: DEGUSSA

    Inventor： PRESCHER GUENTER DIPL CHEM DR ,  SCHREYER GERD DIPL CHEM DR

    IPC: B01J23/92 ,  C07D301/12 ,  C07C59/14

    Abstract: Pure racemic tartaric acid and mesotartaric acid are prepd. by reaction of an alakali metal maleate with aq. H2O2 in the presence of an alkali metal tungstate with a mole ratio of H2O2:maleic acid greater than 1 and the alkali salts of cis-epoxysuccinic acid formed with the alkali metal tungstate, opt. after decompsn. of excess H2O2, are converted to free cis-epoxysuccinic acid and free tungstic acid by passage through a strong acid cation-exchanger and hydrolysis of the cis-epoxysuccinic acid into the desired prodt. is effected either in the presence or absence of the tungstic acid, the tungstic acid being sepd. by an anion-exchanger, and the racemic tartaric acid is then sepd. by crystallisation in known manner from the hydrolysate free of tungstic acid, opt. by evapn. of water and lowering of the temp., after which the mesotartaric acid remaining in the mother-liquor is obtd. by crystallisation by evapn. to dryness opt. in a mixt. with racemic tartaric acid, unreacted cis-epoxy-succinic acid and maleic acid, whilst the anion-exchanger charged with tungstic acid is regenerated in known manner by a dilute alkali soln. and the alkali metal tungstate obtd. is opt. directly recycled to the epoxidation stage, after treatment with active carbon. The mole ratio of H2O2:maleic acid is pref. 1.01-5:1 esp. 1.1-1.3:1. The process is pref. carried out in a series of circulating reactors. Suitable alkali metal maleates and tungstates are of K, Na and ammonium. Racemic tartaric acid is obtd. at very pure state suitable for use in foodstuffs and in high yield.

    6.
    发明专利
    未知

    公开(公告)号：DE2363867A1

    公开(公告)日：1975-09-04

    申请号：DE2363867

    申请日：1973-12-21

    Applicant: DEGUSSA

    Inventor： GEIGER FRIEDHELM DIPL CHEM DR ,  HEIMBERGER WERNER DIPL CHEM DR ,  SCHMITT HERMANN ,  SCHREYER GERD DIPL CHEM DR

    IPC: C07D251/28 ,  B01D15/00 ,  B01D53/02 ,  B01D53/28 ,  B01J19/00 ,  B01J20/08 ,  C01C3/00

    Abstract: Cyanogen chloride is purified and the service life of activated carbon is increased in the subsequent trimerization of the cyanogen chloride to cyanuric chloride by process comprising reacting hydrogen cyanide with chlorine, in a given case in the presence of cyanogen chloride produced in the presence of water, which in a given case contains chlorine. The improvement comprises passing the cyanogen chloride over granular gamma aluminum oxide with an alkali metal or in a given case an alkaline earth metal content of 0 to 3 weight % at 20 DEG -100 DEG C., preferably 30 DEG -60 DEG C.

    Cyanogen prepn from hydrogen cyanide and cupric ions - in the absence of oxygen then oxidising and recycling cupric solution
    8.
    发明专利
    Cyanogen prepn from hydrogen cyanide and cupric ions - in the absence of oxygen then oxidising and recycling cupric solution 未知

    公开(公告)号：DE2461204A1

    公开(公告)日：1976-07-01

    申请号：DE2461204

    申请日：1974-12-23

    Applicant: DEGUSSA

    Inventor： HEIMBERGER WERNER DIPL CHEM DR ,  SCHREYER GERD DIPL CHEM DR ,  SCHMITT HERMANN

    IPC: C01C3/00

    Abstract: Cyanogen is prepd. by oxidising hydrogen cyanide, using cupric ions opt. with the addition of ferric ions as catalysts, in a first reactor free from oxygen after which the cyanogen formed is removed from the solution opt. by evaporation; the solution contg. cuprous and opt. ferrous ions is then re-oxidised in a second reactor using oxygen or an oxygen contg. gas pref. air at >=5 (20-30) atmospheres and is then recycled to the first reactor. The oxidation stage is pref. carried out at pH 0 to 1 partic. 0.3 to 0.5 and the re-oxidation stage is pref. carried out in a packed column. Processes using oxygen to effect the oxidation of HCN give impure cyanogen whereas the above process gives cyanogen over 95% pure in very good yields.

    9.
    发明专利
    未知

    公开(公告)号：DE2363866A1

    公开(公告)日：1975-09-04

    申请号：DE2363866

    申请日：1973-12-21

    Applicant: DEGUSSA

    Inventor： GEIGER FRIEDHELM DIPL CHEM DR ,  HEIMBERGER WERNER DIPL CHEM DR ,  SCHREYER GERD DIPL CHEM DR

    IPC: C07D251/28 ,  B01D15/00 ,  B01D53/02 ,  B01D53/26 ,  B01J19/00 ,  B01J20/18 ,  C01C3/00

    Abstract: Cyanogen chloride is purified and the service life of activated carbon is increased in the subsequent trimerization of the cyanogen chloride to cyanuric chloride by process comprising reacting hydrogen cyanide with chlorine, in a given case in the presence of cyanogen chloride produced in the presence of water, which in a given case contains chlorine. The improvement comprises passing the cyanogen chloride over granular commercial sodium aluminum silicate or a molecular sieve of the mordenite type, at 20 DEG -100 DEG C., preferably 30 DEG -60 DEG C.

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