Method for the fractional condensation of a hot gas mixture containing acrylic acid or methacrylic acid and having a high proportion of non-condensable constituents
AssigneeBASF SE
InventorsBernd Eck, Otto Machhammer, Theo Proll, Volker Schliephake, Joachim Thiel, Klaus Bröllos
Life of this patent
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Abstract
A process for the fractional condensation of a gas mixture which, in addition to acrylic acid or methacrylic acid, also contains at least one further condensable component and additionally a high proportion of one or more noncondensable components, wherein the gas mixture is passed through a column having separatory internals and the condensable components are condensed by cooling.
Claims14
A process for the fractional condensation of a gas mixture comprising acrylic acid or methacrylic acid, at least one further condensable component, and additionally a high proportion of one or more noncondensable components, the process comprising passing the gas mixture through a column having separatory internals, condensing the condensable components by cooling, and removing acrylic acid or methacrylic acid having a purity of more than 95% by weight from the column.
A process for the purification of acrylic or methacrylic acid comprising:
- cooling a hot gas mixture comprising acrylic or methacrylic acid, at least one additional condensable component selected from the group consisting of water, acetic acid, formaldehyde, maleic anhydride, benzoic acid, acrolein, phthalic anhydride, propionic acid, maleic acid, allyl acrylate, benzaldehyde, fufural, and phenothiazine, and 20-98% by weight of a noncondensable component selected from the group consisting of nitrogen, oxygen, carbon monoxide, carbon dioxide, methane, propane and propene;
- injecting the cooled gas into a column comprising separatory internals at a lower portion of the column;
- removing the heat of condensation from the lower portion of the column with a heat exchanger, thereby removing a condensed high boiler fraction comprising one or more compounds selected from the group consisting of maleic anhydride, benzoic acid, stabilizers, monomeric and oligomeric acrylic acid from the column;
- recirculating a portion of the condensed high boiler fraction into the column;
- removing a medium boiler fraction comprising acrylic acid or methacrylic acid at a middle portion of the column;
- removing the heat of condensation from an upper portion of the column with a heat exchanger, thereby removing a condensed low boiler fraction comprising one or more compounds selected from the group consisting of water, acetic acid, and formaldehyde from the column;
- recirculating a portion of the condensed low boiler fraction into the column;
- removing uncondensed gases from the upper portion of the column.
Dependencies are inferred from the claim text.