Principles of Ethanol Organosolv Lignin Precipitation: Process Simulation and Energy Demand

Abstract

This study focuses on ways to precipitate lignin, and how the choice of pr-econcentration technique affects an ethanol organosolv (EOS) processes’ energy and chemicals demand. Experiments were performed in order to precipitate lignin from an EOS treatment liquor by a) direct precipitation with sulphuric acid, b) vacuum-assisted evaporation and acid precipitation, and c) concentration by nanofiltration and acid precipitation. Utilizing the process simulation tool ASPEN Plus ®, supported by experimental data, energy and chemical demand were calculated. It was shown that chemicals demand decreased significantly by preconcentration and that the energy demand for the nanofiltration case was considerably lower than in the evaporation case.