In this contribution a test distillation and a column model are presented for a quaternary system containing methyl isobutyl ketone, water, acetic acid and furfural. This chemical system is relevant for liquid-liquid extraction and distillation of extract and raffinate of wood hydrolysate, a potential source for valuable biorefinery products. The model is based on previous vapour-liquid and liquid-liquid experiments carried out in our laboratory. The laboratory distillation column was specifically designed for two liquid phase distillate and reflux stream. Temperatures, heating power, mass fractions and mass flows were measured during the experiments. The number of ideal stages in the column were determined with a separate two-component run. The simulated outlet compositions of all three products (bottoms, organic distillate and aqueous distillate) agree very well the experiments, and based on simulation model the heat loss was approximated. This work gives further confidence when large-scale separation sequences relevant to biorefinery operations are designed.