Patent ID: 8557000

Claim:
A process for converting lignocellulosic materials to a liquid biofuel comprising lignin dissolved in ethanol produced from cellulosic components, the process comprising: A) hydrolyzing lignocellulosic feed materials in three concurrent stages including a first stage operated at a temperature of about 400 K that produces a first product stream and a first remainder stream, a second stage operated at a temperature of about 400 K that produces a second product stream and a second remainder stream, and a third stage operated at a temperature of about 400 K that produces a third product stream and a third remainder stream; wherein the first remainder stream is fed into the second stage and the second remainder stream is fed into the third stage, wherein the three product streams are separately withdrawn, and each consists of solubilized fragments selected from the group consisting of hemicellulose components, lignin components, and cellulose components and mixtures thereof, wherein the hemicellulose component is removed in the first product stream in said first stage and is subjected to fermentation and then distillation to produce ethanol, wherein the lignin component is removed in the second product stream in said second stage and comprises a mixture of lignin, water, organic solvent vapors selected from methanol, ethanol, and acetone, or mixtures thereof, and catalyst comprising hydrochloric acid and iron (III) chloride, is subjected to filtration to produce a filtrate and a solid lignin component, wherein the lignin is washed with water and dried and the filtrate is passed through a pressurized thin film evaporator at a temperature of about 475 K, whereby volatile organic compounds are removed from the liquid stream as a vapor and the catalyst is separated and reused in the second stage, wherein the cellulose component is removed in the third product stream in said third stage wherein the third product stream is subjected to fermentation and then distillation to produce ethanol, and B) combining the processed product streams to recover a product containing lignin and ethanol and having a high calorific value suitable for use as a liquid biofuel.