WO/2008/144903 is referenced by 45 patents.
A process for concurrent production of lignins, fuel alcohol, and biogas from lignocellulosic feedstocks. The process comprises: (1) pretreating a lignocellulosic feedstock to produce a solubilised liquid components stream comprising lignins, lignin-derived compounds, and a cellulosic pulp stream, (2) separating the liquid stream from the cellulosic pulp stream, (3) processing the liquid stream to separate and recover at least lignins, lignin-derived compounds, and semi-solid waste material, (b) processing the cellulosic pulp stream to saccharify and ferment the cellulose pulp to produce a beer which is then separated into fuel-grade alcohol and a waste stillage material, (4) anaerobically digesting the semi-solid waste material from the liquid stream and the waste stillage material to produce a biogas. The rate of anaerobic digestion can be manipulated by controllably supplying a portion of the monosaccharides produced from the cellulosic pulp. The cellulosic pulp stream may also be anaerobically digested.