Continuous counter-current organosolv processing of lignocellulosic feedstocks

A modular process for organosolv fractionation of a lignocellulosic feedstock into component parts and further processing of said component parts;

• the modular process comprising:
• a first processing module provided with a first series of steps for receiving, physically screening, and physico-chemically digesting a lignocellulosic feedstock by commingling and circulating therethrough an organic solvent separately provided thereto thereby extracting component parts therefrom, and separating said component parts into a cellulosic solids fraction and a first liquid fraction;
• a second processing module provided with a second series of steps for producing at least a fuel-grade ethanol and a stillage from said cellulosic solids fraction and separating a plurality of a first class of lignin derivatives from said stillage;
• a third processing module provided with a third series of steps comprising at least a first step for separating the first liquid fraction into a first filtrate and a second solids fraction comprising a plurality of a second class of lignin derivatives, a second step for separating the first filtrate into a second filtrate and a third solids fraction comprising a plurality of a third class of lignin derivatives, and a third step for separating furfurals from said second filtrate, a fourth step for recovering a portion of the organic solvent from the second filtrate by distillation thereby producing a stillage;
• and
• a fourth processing module provided with a fourth series of steps for separating the stillage from the third processing module into at least an acetic acid-containing liquid fraction, a plurality of a fourth class of lignin derivatives, a lipophylic extractives fraction, a monosaccharide sugar syrup, and a solid waste material.