| abstract |
A process for purifying (meth) acrylic acid with a process step for working up a composition Z1 comprising (meth) acrylic acid, water, (meth) acrylic acid dimers, protoanemonin, maleic acid and maleic anhydride, comprising the following steps: a) feeding the composition Z1 into a dimer gap reactor and cleavage of the (meth) acrylic acid dimers at a temperature in a range of 50 to 300 ° C; b) removing the overhead product of the dimer gap reactor as a composition Z2 and a bottoms product of the dimer gap reactor as a composition Z3; c) separating (meth) acrylic acid from the composition Z2 by converting the (meth) acrylic acid into the gas phase, whereby a (meth) acrylic acid-based composition Z4 is obtained as a separated product. |