METHOD OF LAUNCHING THE PROCESS OF CLEARING OF ACRYLIC ACID CRYSTALS FROM SUSPENSION S WITH ITS CRYSTALS IN THE MOTHER LIQUOR Russian patent published in 2018 - IPC C07C57/07 C07C51/43 C08F20/06 

FIELD: biochemistry.

SUBSTANCE: invention relates to a process for the polymerization of acrylic acid with itself or with at least once ethylen-unsaturated compounds, with the acrylic acid crystals used as a starting material obtained by separating from the suspension S of its crystals in themother liquor, which are obtained by a separation process for purifying separation of acrylic acid crystals from the suspension S of its crystals in a mother liquor using a device, comprising a hydraulic washing column having a rotational symmetry about a longitudinal axis extending from the top to bottom of the working space, bounded by a cylindrical wall and two termini, lying on the axis of symmetry opposite to each other, and when starting the separation process for the initial formation of a layer of crystals in the working space of the circulation circuit of the melted crystals, including the space of the melted crystals, as well as the working space of the previously empty wash column, is first filled with the starting liquid AT, containing acrylic acid, such that the level of the working space filling with the starting liquid AT to be at least higher than the output device, then the filling of the wash column is continued, for which with the ST* stream of the slurry S from the source QS is supplied by the pump P2 through the supply connections E1, E2 through the distribution space and through the passages U into the working space of the washing column, and from the flow of waste mother liquor SM*, which was discharged through the filter tubes from the flushing column, as a source of QT* if necessary, the supply pump P3 is driven by a part of the flow as a flow of the regulating mother liquor SL* through the supply connections C1, C2 through the distribution space and the U passages and/or directly into the working space of the scrubbing column and continue this at least as long until the moment t_S, in which the pressure difference P_D = P_K – P_V, where P_K is the pressure, in each case, available at an arbitrarily chosen location in the crystal melt space at a certain time of flow ST*, and P_V – this is in each case the pressure available at an arbitrarily chosen location in the distribution space at the same time, does not increase depending on the duration of the flow of the flow ST* and does not remain constant, but drops sharply, and, that before the moment t_S the average surface load on the filters F, calculated from the arithmetic mean as a whole during the flow time ST* through filters F of the filter tubes up to the point in time of the current flow of the exhausted mother liquor SM*, divided into the total area of all filters F, is not more than 80 m³/(m²⋅h), the starting fluid AT containing acrylic acid is a liquid, upon cooling of which, prior to the start of crystallization, the crystals precipitating therefrom are acrylic acid crystals, and between the crystallization temperature T^KB of these crystals of acrylic acid in the starting liquid AT, indicated in degrees Celsius, and the temperature T^S of the suspension S of the ST* stream indicated in degrees Celsius, the relation T^KB ≤ T^S + 15 °C.

EFFECT: invention relates to a process for the polymerization of acrylic acid with itself or with at least once ethylen-unsaturated compounds.

27 cl, 3 dwg, 1 ex