67.
    发明专利
    未知

    公开(公告)号:DE19926082A1

    公开(公告)日:2000-12-14

    申请号:DE19926082

    申请日:1999-06-08

    Applicant: BASF AG

    Abstract: The invention relates to a method of purifying and producing acrylic acid or methacrylic acid by crystallization. As a result of the crystallization, a crystallized product and a mother liquor is obtained and the crystallized product is washed at a temperature of 15 to 40 DEG C with a wash solution that contains the acid. The invention further relates to a method of producing acrylic acid or methacrylic acid that comprises the above-mentioned purification method.

    69.
    发明专利
    未知

    公开(公告)号:DE19718088A1

    公开(公告)日:1998-11-05

    申请号:DE19718088

    申请日:1997-04-29

    Applicant: BASF AG

    Abstract: - Crystallisation of a material (I) to be recovered involves (i) evaporation of a fluid (II) from a melt or solution containing (I), (II) and optionally other components; and (ii) condensation or absorption of (II) vapour in a liquid material to form a liquid mixture, in which (I) and (II) are selected from (a) inorganic salts and salts of organic compounds and their solvates, preferably hydrates, in water and/or organic solvents; (b) organic components in a mixture of organic compounds and/or water with close boiling points, where the difference in concentrations of the gas and liquid phases in equilibrium at the crystallisation pressure and temperature is

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