Method for recovering di-trimethylolpropane by distillation

Distillative process for obtaining ditrimethylolpropane from solutions comprising ditrimethylolpropane, consisting of:

• (a) producing the solution comprising ditrimethylolpropane from the residues of trimethyl propane with the addition of water and separating the comprising ditrimethylolpropane in a first distillation unit into a first tops fraction comprising low-boiling compounds having a lower boiling point than ditrimethylolpropane and a bottoms fraction;
• (b) introducing the bottoms fraction as obtained after step a) into a second distillation unit having at least 5 theoretical plates, said unit being configured as a thin-film evaporator with a column attachment, and drawing off a second tops fraction comprising intermediate-boiling compounds having a lower boiling point than ditrimethylolpropane is, and withdrawing a bottoms fraction;
• and
• (c) introducing the bottoms fraction as obtained after step b) into a third distillation unit having at least 4 theoretical plates, said unit being configured as a thin-film evaporator with a column attachment, in which ditrimethylolpropane is obtained as a third tops fraction and high boilers are removed as a bottoms fraction.

Distillative process for obtaining ditrimethylolpropane from solutions comprising ditrimethylolpropane, consisting of:

• (a) treating the solution comprising ditrimethylolpropane with an ion exchanger and separating the solution comprising ditrimethylolpropane in a first distillation unit into a first tops fraction comprising low-boiling compounds having a lower boiling point than ditrimethylolpropane and a bottoms fraction;
• (b) introducing the bottoms fraction as obtained after step a) into a second distillation unit having at least 5 theoretical plates, said unit being configured as a thin-film evaporator with a column attachment, and drawing off a second tops fraction comprising intermediate-boiling compounds having a lower boiling point than ditrimethylolpropane, and withdrawing a bottoms fraction;
• and
• (c) introducing the bottoms fraction as obtained after step b) into a third distillation unit having at least 4 theoretical plates, said unit being configured as a thin-film evaporator with a column, attachment, in which ditrimethylolpropane is obtained as a third tops fraction and high boilers are removed as a bottoms fraction.