Biomass ethanol production generates great amounts of residuals,
both liquid and solid. Among the liquid residuals are the pretreatment
liquor, rich in pentoses, soluble and insoluble lignin;
and the vinasse, the effluent after ethanol recovery. There are also
solid wastes from the hydrolysis process, composed mainly of lignin
and hemicelluloses that are not solubilized during pretreatment
and hydrolysis.