Recovery of lignin and furfural from acetic acid-water-HCl pulping liquors.

The feasibility of the HCl-water-acetic acid pulping technology (Acetosolv process) depends on the efficiency of solvent and byproduct recovery. Experimental data and computer simulation calculations are presented to assess these points. The recovery of precipitable, dissolved solids derived from lignin by mixing pulping liquors and water in various proportions was studied. Computer simulation of selected operational strategies enabling the recovery of furfural from the liquors obtained in the lignin-precipitation stage are also presented.